Do I need to recalibrate z-probe offset every time I switch to a different layer height? It occurs to me that I'm never really thinking about layer height when I calibrate my z-probe offset. This is obviously an oversight, because I'll want my nozzle to start higher for 0.3mm layers than for 0.1mm layers.

After this realization comes the question: Do I need to recalibrate every time I switch to a different layer height? Or can slicers store a reference layer height + probe offset and just deduce the proper starting height for every print? Or is it smartest to keep the 1st layer height constant throughout my prints to spare myself this frustration?

If it matters, my printer is the Printrbot Simple Metal, and my goto slicer is Cura.

All modern slicers adjust the nozzle position for the first layer in accordance with your chosen layer height. You can see this in your gcode if you slice files with different layer heights. Before you add special slicer settings and offsets, if you print 0.1mm layers, the nozzle will start at Z=0.1mm, and if you print 0.3mm layers, the nozzle will start at Z=0.3mm.

There are two reasons this is more complex and less reliable than it seems:

Different slicers assume different initial tramming gaps. And your actual tramming gap may not match that assumption. If the slicer thinks your nozzle is leveled at Z=0 with a real physical gap of 0.1mm to start with, that means gcode Z=0.1mm is actually a 0.2mm gap that must be filled with plastic. So the slicer must compensate by starting lower than the nominal layer height.

So what works perfectly for one slicer won't necessarily work correctly for another slicer. And if you tram with a thinner object than the slicer expects (say a post-it note instead of business card) then your first layer will be off.  This is why I personally prefer physical build plate leveling mid-print using screws while watching the strands go down. It bypasses all the assumptions about tramming gaps and just gives you the correct result. (Or you can do the same thing with babystepping in firmware that supports that.)

The other issue is that people use lots of weird, ad hoc slicer tricks to get their first layer to stick. Things like printing the first layer much hotter, or at half speed, or squashed way down and over-extruded, or at 60% layer height, or at 200% extrusion width, will all affect the extrusion volume calibration and the space-filling behavior of the molten plastic flowing onto the bed. The slicer doesn't really have the ability to understand "your" first-layer adhesion recipe.

The combination of incorrect/unknown tramming gap and person-specific first-layer settings is why the slicer can't always get the first layer height and extrusion volume correct across all layer heights. Within some fairly reasonable assumptions, the slicer is smart enough to always correctly relate extruder flow and nozzle position so it fills the space between the nozzle and whatever surface you're printing onto. But if you break those assumptions, it may perform differently for different settings.


Hotend on a Neutron printer: E3D vs MK8 I own a Creality Ender 3 printer, and have been printing on it for about a year.

I thought it might be fun and instructive to build a Neutron printer (https://cobyhuang.com/ATOM-Neutron) using my Ender 3 to print the parts.

The Neutron printer can use either an E3D hotend, or an ATOM 2.5 MK3 hotend.

I think that the E3D hotend is more common, so I think that is the one I'll go with.

It occurs to me that the heater block for an E3D hotend uses an M6 thread for the heat break and the nozzle. Likewise, my Ender 3's heater block also uses M6 threads.

Here is my question, it is possible to replace the heater block and nozzle on an E3D hotend with a heater block and nozzle from an Ender 3? Not that I'd disassemble my Ender 3 mind you, but it would be nice to have one set of interchangeable parts.

Yes, but...
Technically, you can reuse your old heater block and nozzles and just buy a new heartbreak and cooling body or the other way around. However, you might run into problems under working conditions, especially if you install the heater block together with its native heating cartridge and thermosensor. Installing a thermosensor to which the printer is not adjusted to can lead to all kinds of problems - Firmware update is a must!
Another source of trouble could stem from not taking care in the change itself. The Makerbot MK8 seals the hotend by pressing the liner against the nozzle, which itself is seated against the heartbreak, just like the e3D lite6 seals itself. On the other hand an all-metal e3D v6 seals itself by seating the heartbreak against the nozzle on a larger area. If the seal is imperfect, the Makerbot Mk8 style tends to leak out through the top. Such a leak can leave plastic in the threading which has to be removed carefully before reusing.


Which resolution is needed for bricks compatible with Lego? I found a story about someone 3D-printing equipment for their Lego minifig, using an Ultimaker. (Article is in Dutch, but accompanied by photographs).

I noticed that what they made weren't the actual connecting bricks, but the tools used by the minifig. And that even so, some filing and a dremel were needed afterwards to make them fit properly.

I'm told that to make something connect properly with real Lego, the machine needs to be tuned very precisely.

So, what resolution is needed to print bricks that will connect with normal Lego bricks?

It's really more about calibration than resolution -- a poorly calibrated printer will have dimension errors that prevent mating with true LEGO bricks or other printed bricks.

Also, "resolution" is an incredibly loaded term for 3d printers, because it can mean a lot of different things. But we don't need to get into that right now. There are really two big things to worry about: layer height and extrusion width.

Layer heights of 0.1mm or 0.2mm should be fine. Coarser layers may run into surface finish issues that make the bricks difficult to put together or take apart. There probably isn't much reason to go finer than 0.1mm for this application. Almost all FFF printers can do 0.1mm layer heights as long as it is reasonably well-tuned.

Any typical household FFF printer with a "normal" nozzle size can print fine enough for the bricks to work. It just needs to be tuned well. The smallest "must have" feature in a standard lego brick is the 1.6mm thick wall around the sides. The typical minimum printable feature size for an FFF printer is 2x the extrusion width, because the slicer will place a path on the inside edge of the shape and the outside edge of the shape. (Some slicers will allow single-extrusion features, but this is not generally recommended because it makes weak parts.)

So, how wide is the extrusion width? It's adjustable, and different slicers auto-recommend different values, but as a safe rule of thumb it needs to be between 1x and 2x your nozzle size. There are some volume calculation quirks in different slicers that may encourage larger or smaller sizes, so sometimes people recommend [extrusion width = nozzle size + layer height] particularly with Slic3r. This is very system-specific.

Assuming you have the most common stock nozzle with a 0.4mm orifice, and also set the extrusion width to 0.4mm, the slicer should put four strands in the walls of the LEGO brick. That's good.

Where it gets tricky is if you have an extrusion width that does not evenly divide into 1.6mm. Say you are printing with an extrusion width of 0.6mm. There is enough room in the wall of the part to place two full 0.6mm perimeter strands... but then a gap 0.4mm wide will be left in the center. You can't put another 0.6mm strand into that 0.4mm gap. Different slicers handle this different ways. Some will leave an empty space between the walls, and you get a very weak print. Some will mash an excessive amount of plastic into the gap, causing poor print quality as excess material builds up more and more on each layer. Some will push a smaller-than-commanded strand to try to properly fill the volume.

So, the general advice with small features is to make sure your extrusion width goes into the part's minimum thickness a reasonable number of times.

[Feature size / extrusion width < 2] is BAD
[Feature size / extrusion width = 2] is GOOD
[2 < Feature size / extrusion width < 3] is BAD
[Feature size / extrusion width > 3] is GOOD

Although these will vary somewhat by slicer -- older slicers like Skeinforge tend to have more issues with this than newer slicers. What you should do in practice is check your slicer's print previewer to see whether it is leaving a gap between the strands. Then adjust extrusion width and perimeter/shell count to try to get an intelligent output. There's some trial and error involved.


Infill pattern comparison I'm relatively new to 3d printing, and wanted to get a few things understood.
Firstly, I am unclear on how Hexagonal infill is stronger than, say, diamond pattern.

Can anyone explain how the different shape causes the structure to be stronger? I saw a few places that hex is stronger; usually, more vertices means 'weaker' shape (i.e. a triangle is stronger than a square), so how does that work with hex vs diamond?

Also, in small objects, where the printer makes only a single dot as the infill (a dot instead of a line in larger objects), does the infill strengthen the object at all?

EDIT: I am trying to understand the effect of the infill pattern on the strength of the print, regardless of print time.

Hex grids are used for different reasons than triangular grids (such as you often see on bridges and roof systems). Triangles are especially good at being rigid, while hex grids are very material-efficient for a given strength. The second reason ($) is typically more important for 3D printing.

Triangles do have fewer vertices than squares, but it's not always true that "fewer vertices" means stronger. Vertices are one kind of weak point. But in a triangle, vertex "angle-holding" failures simply don't matter. You can fasten 3 bars together with hinges or other joints that have little resistance to changing angle, and the triangle is still rigid.

In contrast, rectangular grids can (and do -- https://www.youtube.com/watch?v=5t9MpNTSbYg) completely collapse if their vertices aren't rigid enough. That combines badly with the fact that vertices concentrate forces, so have to be much stronger than sides in comparable settings.

A triangle cannot change without changing multiple things -- at least 2 angles and a side, or all three sides. Intuitively, the sides and vertices of a triangle work together for strength. This advantage of triangles doesn't transfer to hexagons, but hexagons have two other advantages: First, if you want to fill a space with a repeating shape, hexagons use less material than other shapes. And second, hexagons keep all the individual "walls" shorter compared to others shapes, which makes them less prone to bend.

The material efficiency was proven by Thomas Hales in 1998, according to http://www.slate.com/articles/health_and_science/science/2015/07/hexagons_are_the_most_scientifically_efficient_packing_shape_as_bee_honeycomb.html. His paper "The Honeycomb Structure" is available at https://www.communitycommons.org/wp-content/uploads/bp-attachments/14268/honey.pdf


Probe instead of nozzle centres on the bed Problem is that the probe is in the center of bed instead of the nozzle. How fix it on my Tronxy X5SA?
Those are my current settings and the nozzle is shifted from the centre (X: 35 mm, Y: 3 mm):
#define NOZZLE_TO_PROBE_OFFSET { -37, 3, 0 }
#define Z_SAFE_HOMING

(Marlin 2.0 configuration)

TL;DR You don't need to fix it, it is by design.

When using a probe, defined the correct probe X (xxx) and Y (yyy) offsets (#define NOZZLE_TO_PROBE_OFFSET { xxx, yyy, 0 }) and having enabled #define Z_SAFE_HOMING will cause the probe to home in the middle. That is how it is supposed to work!
If the nozzle would be in the center, then you wouldn't probe the middle of the bed, but the offset from the nozzle.


Acceleration with Marlin I expected that the movement of an axis would start slowly, become faster and then run at a constant speed when reaching the maximum speed, then slow down slowly and arrive at the target point at the lowest speed.

At my DIY machine, however, I achieve a constant, very low speed at the beginning, then jumpy change to the maximum speed, finally a also jumpy change to the low speed, which also happens at the beginning.

I've been working on the Marlin settings for days, but I haven't had the slightest success.

Why don't I get any rising and falling ramps, why the sudden change?

These are my current Marlin settings:

G21    ; Units in mm
M149 C ; Units in Celsius
Filament settings: Disabled
M200 D1.75
M200 T1 D1.75
M200 D0

Steps per unit:
M92 X800.00 Y640.00 Z800.00 E500.00

Maximum feedrates (units/s):
M203 X200.00 Y200.00 Z12.00 E25.00

Maximum Acceleration (units/s2):
M201 X5000 Y5000 Z1000 E10000

Acceleration (units/s2):
P<print_accel> R<retract_accel> T<travel_accel>
M204 P3000.00 R3000.00 T3000.00

Advanced: S<min_feedrate> T<min_travel_feedrate> B<min_segment_time_ms> X<max_xy_jerk> Z<max_z_jerk> E<max_e_jerk>
M205 S0.00 T1000.00 B20000 X10.00 Y10.00 Z1.00 E5.00

What's the secret of a beautiful ramp?

Your steps/mm settings are very high. Assuming you are running an ATMEGA based controller, like RAMPS, you will only be able to move at very slow feed rates (<20mm/s). There are also many hardware factors that influence your maximum speed at a given steps/mm (which is typically referred to a your maximum step rate):

Supplied voltage. Using too high/low voltage can cause poor stepper performance or create unexpected faults at high/low step rates.
Motor specifications. Stepper motors come in a dizzying number of models with varying specifications. This is because each one is tailored to a specific use case.
Stepper Driver. There are a bunch of driver designs and manufacturers out there and none of them should be considered equal. It also matters how you setup the driver in terms of current/voltage limits, microstepping, decay modes, heat syncing, etc.
Wiring. At high step rates the inductance of the wires between your controller and motors start to matter more, as does interference to/from other electrical devices.

If you aren't sure how to set/select/tune the things above it's best to just mimic what is done on common printers like the Prusa i3, which have robust designs.

In more direct regard to your Marlin settings, your acceleration and feedrate values are very high for an untested printer. It's best to start with conservative values (Accel ~500mm/s^2, Feedrate <10mm/s) and work your way up 10% at a time until you start having issues, then back off ~20% from there.


Printer extrudes too little filament at beginning and end of extrusion I've bought a new type of filament (GreenTEC Pro Natural) for my Anycubic Mega i3 to print some food-safe cookie cutters. Now I have changed the print settings to an extruder temperature of 210 °C and a heated bed temperture of 60 °C and everything works well.

But when I look at the print, I see that too little filament is extruded at the beginning of an extrusion and at the end. So every time the nozzle is lifted to move without extruding, it takes too long for the filament to correctly start extruding again (see picture).

What can I do? Is there a setting to print slower at these points (I'm currently using Cura)? Maybe change retraction distance? Different extrusion temp? Before I used PLA from Anycubic and everything worked fine...

I think there's a retraction issue(had the same issue). You need to change retraction and check whether there are any improvements. Some times different filament types need slight filament setting calibration.


How to decide print orientation? Please Note: This question is not about the design. It's about deciding print orientation after the design.

I have a small, but complex piece which I need to print. Here are two images of different orientation for you:

No matter how I orient it, it will require a support structure. Any which way I print it, I believe there will be pros/cons to doing so. My question is, Is there a thought process for how to orient the part for printing? What are some of the things to consider when deciding print orientation?

Note-1: For a size reference of the part, looking at the second image, it is approximately 60 mm from the top of the long bottom part with the two "claws" point down, to the top of the vertical piece which has the two larger chamfered holes in it. In the same image, the left part will be at the bottom when put into use, though will be suspended (the chamfered holes will have wood screws in them, with a block of wood on the other side from the chamfers.

Note-2: For this example, I will be using Priline PLA filament on an Anet-A8 printer.

To answer the generic question "Is there a thought process for how to orient the part for printing?", I would say "Yes there absolutely is such a process!".

Part of this though process can be aesthetics, structural strength, limiting filament waste, print duration, etc.

For the given example I would try to think of the load case (if it has to bear a load) that subjects the part and prevent a perpendicular load to the deposition plane. If the load is low or non existent, you could orientate the print such that you minimize wasting material, or get the best aesthetics (removing supports can leave its scars).


Best way to fix ABS corner curling on enclosed Prusa style printer with PEI heatbed? I'm trying to set up an enclosed (custom enclosure) Prusa i3 style printer for ABS, but having a fair amount of difficulty preventing the part corners from curling.

Detailed specs:

Geetech A10 (generic Prusa clone) w/ PEI heatbed
Custom enclosure
Slic3r software
ABS filament (obviously!)
247 °C hotend temp
115 °C heated bed first layer, 110 °C for others
Fan on for layer 3 and above

Verified heatbed temperature with calibrated IR imager.

Thus far I have been unable to prevent parts from separating from the heatbed during print, primarily at the corners where stress is concentrated.  I've tried various heatbed temperatures from 90 °C to 115 °C, lower hotend temperatures (which just made the problem worse and caused complete print failure), cleaning the PEI surface with alcohol, etc. to no avail.  I'm even seeing this to some extent with Benchy, it shows up as a lift to the stern and bow (slight bend parallel to the keel) -- the print is otherwise basically perfect.

I've attached an image of the more extreme curling -- yes, I should probably be using mouse ears on a part like this, but I see the same thing on parts that shouldn't require mouse ears.

What is the best way to fix this particular problem?  Temperature adjustments, brims, rafts, something else?

Adding 20mm mouse ears was sufficient to resolve the problem using the original extrusion / heatbed settings.  I did not expect mouse ears to be required on the Benchy model, but given the lack of better advice it seems this may be a poorly documented "feature" of ABS.

Results on the original worst-case test model:

Note that the brims will not help if the bed is insufficiently leveled -- the brim has to actually merge with / melt into the base part layer, so the extruder height has to be perfect at the brim to part interface.

Example of extruder too far away from bed:


Will glue sticks form a barrier on a build surface to prevent PETG from damaging the surface? Will glue sticks, such as Elmer's All Purpose, Cra-Z-Art washable or Scotch Permanent, form a barrier on a build surface to prevent PETG from damaging the surface?  While forming a barrier that holds the PETG print down, does it allow the PETG to separated after the print finishes, so that the build surface isn't damaged?
I found in the description of a glue stick designated for 3D-printers: "these 3D printer glue sticks can be applied to remove 3D models much easier .. made of quality PVP material ... have nice adhesion to hot plate or hot bed, easy to remove the printing models ..."
I'm now using an Elmer's washable school glue stick (PVP).  It is working consistently at bed temperatures of 30°C and 80°C. It both holds the PETG print and releases the print without destroying the build surface.

I don't know about PVP but PVA sticks more at room temperature and gets weaker at higher temperatures, see "Influence of temperature on the strength of bonded joints"

I remember using hairspray with PVA for PETG and it was really difficult to detach large parts.


Shell doesn't cover the entire inner wall at some areas How do I improve/increase shell coverage so that it covers the entire inner wall?
I've experimented with shell settings, but I can't seem to get it right.
I'm using Creality Slicer 4.2.1 (Cura)
Picture showing the areas in question below:

You should increase the top layer thickness according to Ultimaker Cura support:

Top/bottom thickness
With the top/bottom thickness you can set the thickness of the solidly printed top and bottom layers of the print. A higher value ensures all gaps on the top and bottom layers are closed completely. However, this can also increase the print time and amount of filament used.
It is advised to always use a multiple of the layer height for the thickness of the top and bottom. This means, for example, that with a layer height of 0.15 mm, it’s better to set the top/bottom thickness to 0.6 mm rather than 0.7 mm.


Can you print at low speeds with e3D Volcano hot end? The e3D volcano features an extended heater block of length 20 mm with the cartridge heater running parallel to the filament.

The purpose of this is to increase the speeds at which filament can be printed (of course the extruder and other factors may still be limiting factors).

My question is how capable would this heat block be of printing at slow speeds with a 0.4 mm nozzle?

Is printing still possible at lower speeds or is the filament heated too much that jams occur? Is the retraction performance okay?

Speaking from first hand experience running a Volcano hotend, mostly using a 0.6 mm nozzle, but I have used 0.4 mm as well. I can't really complain about any lower printing speed limit (low speeds are usually a solution to high speeds problems for me).

Just for completeness: I am using a DaVinci 1.1 Plus with custom firmware (modified Marlin) and an E3D Volcano hotend. No problems with the nozzle, clean prints! Note: I am using the Titan Aero as extruder but not using the included pancake motor! Went with the original motor of the DaVinci.

And as always: the parameters are key! Given a bit of tuning you can get amazing results! For PLA and ABS I can work without stringing. Although ABS seems to be prone to pitting (slight underextrusion at start of path). TPU and other flex are sometimes a bit of a challenge, but that's mainly due to my own lack of experience there.

The one important caveat here would be to also reduce the nozzle temperature. A possible theory here might be that the filament has more time and surface to heat up.

(Sometimes I go as much as 15 °C lower as compared to normal/high speeds! Usually lower speeds means small pieces for me and in term means a limit to the layer cooling time.)


Is 3D printing feasible for a coaxial rotational joint? In a design that I need to prototype, I have a coaxial, rotational joint between 2 cylinders connected to another coaxial rotational joint between 2 cylinders by a hinge. I have attached the individual part files as well as their assembly where you can use your mouse cursor to check how they move.
Click here for the SolidWorks parts and assembly files

Initially when I 3d printed them by splitting them in half, the outer tube did not close, even after filing the inner tube sufficiently.

Could you tell me an alternative method to get this complicated joint working? I need to 3D print them. I plan to use ABS for the 3D printing.

Thanks for your patience :)

EDIT:
Lubrication: I plan to use grease to lubricate the sliding surfaces.

Clearances:
I printed them without clearances initially (this is my first ever 3D print and I wanted to know how accurate it would be). I then used Dremel and filing tools to file away about 0.5 mm of both the surfaces. It should have been enough for mating the parts. The gap between the edges of the outer shell while trying to close it around is 3-4 mm which doesn't suggest 3D printing inaccuracy. I suspect that the outer tube isn't circular enough in cross section. It meets the inner tube at the the two ends of the semicircle and not inside its belly (you can see it in the picture). I have already tried the obvious, which is removing material from the surfaces wherever the parts touch. The model seems to be too warped for any success. The parts were printed upwards from the bottom, so it is not the warping due to gravity.

Have you considered to use a service to have the part printed? You can print almost anything in one "pass" using selective laser sintering, typically done in nylon. I am currently un-boxing an SLS printer, so I cannot currently offer to print it, but the capabilities of SLS are substantial for parts of this nature. I've read of entire planetary gearboxes being printed, fully assembled, with appropriate clearances for operation, once removed and "dusted," or cleaned of residual powder.

The printer I hope to be assembling soon has 80 micron powder, so the resolution is quite high, although I forget at the moment the x/y/z figures.

Do you think such a method would suit your purposes?

Edit (add):

because FDM printing by nature causes "oozing" especially in the x/y directions, I would not be surprised to learn that your outer piece has a smaller inside diameter than your design has specified. You may have to make adjustments to the design to compensate. Those adjustments would be specific to a particular printer/filament combination as well. Calibration prints would make the task slightly easier.


BLTouch wiring and pin assignments I’m in the process of installing a BLTouch on a Velleman Vertex K8400. The board doesn’t have a dedicated servo pin, so I’ll assign one. No problem there.
The board only has a Z-min pin, so it’s my understanding that I’m supposed to unplug my Z-min cable and plug the BLTouch into the Z-min port.
My question is: "Can't I assign another unused pin as a Z-max, plug the BLTouch into that, adjust the firmware, and leave the existing Z-min sensor plugged in?"
Upon further review, I probably shouldn't have said Z-max, and will be more specific.
This is a Mega 2560 board with 2 available PWM pins. Anything wrong with this setup?
Pins.h:

  #define SERVO_0_PIN 15 //PH3 (PWM)

  #define Z_MIN_PROBE_PIN 16 //PH4 (PWM)

Configuration.h:

=======Z Probe Option=======

  #define Z_MIN_PROBE_ENDSTOP

  #define BLTOUCH

I want be able to keep my Z-min sensor plugged in as a backup to prevent a bed crash just in case the BL touch doesn't trigger. From what I see this should work as long as I make sure the BLTouch triggers before the Z-min. Any issues that anyone can see?

Note: The question has changed after posting this answer. This answer answered the previous question, but is now out-of-date with respect to how the question has changed; I'll update it later, as it is possible what is asked now.

You can change the Z-min and the Z-max pin assignment in Marlin Firmware in the pins_<boardname>.h file, you basically exchange the Z-min and the Z-max. Note that the switch connected to the old Z-min port now becomes a Z-max sensor if you enable that in the firmware; you should therefore remove it (the actual switch) from the minimum Z position.

To enable a BLTouch sensor you require 2 pins free on the microprocessor. One registers the signal of the trigger, the other triggers the servo to stow/deploy the sensor.

You can connect the white/black to the Z-min signal (Z-min pin) and ground of the Z-min connector (or if pins are swapped in the firmware to the Z-max). The other wires need to be connected to +5 V (red), ground (brown) and orange/yellow to a free analog pin (PWM pin):

  BLTouch can be operated in the following condition.
  - One I/O for control (PWM or Software PWM)
  - One I/O for Zmin (Z Probe)
  - GND and +5 V power

The PWM pin should be defined in your pins_<boardname>.h file, e.g.:

#define SERVO0_PIN         5 // RUMBA board

or

#define SERVO0_PIN         27 // ANET board

The Z-max signal pin is no PWM pin for the servo.


Could nail polish damage pure PLA? I would like to use nail polish to paint and smooth a PLA model. Could nail polish damage a model made out of pure PLA?

This is an ugly question, and an ugly answer.

Nail polish doesn't come with an ingredient list. Nor are there MSDS's available to refer to what solvents are in it. So it's "unknown 1"
Most every filament company will not give you a list of compounds for colorants or plasticizers used. MSDS is off the table. So, even though we do know what PLA and ABS is inherently, we have no clue about the other ingredients used to make your particular filament. This is "unknown 2".

What both of these comes down to is a very nasty situation indeed. We know for a fact that ABS dissolves into acetone. PLA does not.... Except we have had reports of PLA that does. When we look further into those responses, and ask them to do a burn test, they smell popcorn and something acrid (ABS).

This guarantees unless we have virgin material and MSDS in hand, you only have a close guess at what material you have. And that's to say nothing about "nail polish", and its components.

There are also other solvents that will dissolve PLA. MakerBot back before they turned evil, noted a solution called Beta Solution (90% isopropyl alcohol, 9% KOH, 1% Al(OH)3  ). This stuff is noted for dissolving PLA and leaving ABS intact.

Long story short: "Could Nail Polish damage pure PLA?" We can't guarantee purity of PLA, we can't guarantee contents of nail polish's solvents. The only answer is to print a swatch and test yourself. Calibration cubes are quick and easy.


How do I enable Expert mode in the Craftware slicer? I'm using craftware, and I'm trying to figure out how to enable expert mode so that I can adjust the extruder/bed temps. I looked all over the application, the user manual, and googled it, but I cannot find the setting to enable it. Any help is appreciated.

I figured it out, you must click the slice button, then among those options, there is s button to switch to Expert mode. Hope this helps someone in the future.


How can I improve the overhang angles my printer can successfully print? Using an FDM printer and PLA or ABS, without adding support material. What modifications can I make to improve how steep an overhang my printer can print before it starts having problems?

The obvious first answer is to add a cooling fan, increasing the airflow over the freshly-extruded material ensuring it solidifies. What other things can improve it?

Does lowing the temperature help? Raising it?

Does speeding up or slowing down the print head help?

Does increasing/decreasing the extrusion diameter, or layer height help?

The two most important things you can do are:

Provide adequate cooling to solidify the plastic quickly
Minimize layer height

Cooling is really obvious. You need the plastic to solidify before it has a chance to sag. PLA in particular has to shed a lot of heat before it is fully solid. A fan and air guide setup using a "squirrel-cage" radial blower around the nozzle is optimal. A little 30mm or 40mm axial fan will not provide optimal performance.

Low layer height when slicing is less obvious, but is extremely effective. When you use thinner layers, two things happen:

There is less melted plastic per pass and a higher surface area to volume ratio, so the fresh material cools faster.
A larger percentage of each strand in the overhang is supported by the previous strand. If you do 0.2mm thick by 0.4mm wide, half of each strand is unsupported. But if you do 0.1mm thick by 0.4mm wide, only a quarter of each strand is unsupported.

When you combine these two effects, it is possible to exceed 70 degree overhangs with good surface quality.

Another lesser factor is printing shells/perimeters inside-out rather than outside-in. This helps anchor the outermost strand a little better as the overhang is built. This is pretty minor though.


What are the advantages of gyroid infill? I've seen a few print time-lapse videos lately which use gyroid infill: wavy lines, which deform across layers so that the waves end up alternating between the two axes. Other than making the time-lapse videos look much cooler, what are the benefits of this infill style compared to the more common hatching or cross-hatching?

From this reference you can read that:

  A gyroid is a naturally occurring structure which be found in
  butterfly wings and even within membranes inside cells. In 2017, MIT
  researchers discovered that when graphene was shaped into a gyroid
  structure, it had exceptional strength properties at low densities.
  They then discovered however, that the crucial aspect of this was
  actually the gyroid structure itself, and that other materials such as
  plastic could benefit from this.

It is assumed that this type of infill has better properties against failure than the normal types of infill we know.

A test conducted by an author named Martin is found here. He printed test specimen and subjected them to bending to test the resistance against shear stress.

From the figure can be concluded that the gyroid infill has a better resistance against bending for a lower weight.

The advantages of gyroid infill over the tested infill types are:

high shear strength, and
low weight (so less filament needed).

On top of these advantages Gyroid infill prints relatively fast with respect to some other infill types and is close to isotropic (i.e. uniform in all orientations), meaning that is very suitable for flexible prints.


Pushing Text into surface - Google Sketchup In Google Sketchup, I have text on a surface that I'd like to push / pull so that the text is etched into, rather than placed upon the surface.  I can't seem to figure this out, the text disappears when I try to push it into the surface and I'm not quite sure what else to try.  Any advice?

Definitely you have to perform substract operation.
Take a look here

Extrude text and then substract it from the object to etch in.


BOSL2 alignment precision problem in OpenScad Why my small cuboids are not perfectly aligned with the big one?
include <BOSL2/constants.scad>
include <BOSL2/std.scad>
use <BOSL2/shapes.scad>

diff("remove")
cuboid([1, 0.5, 0.2], anchor=BOTTOM){
    attach(RIGHT) cuboid([0.2, 0.4, 0.1], anchor=TOP, $tags="remove");
    attach(LEFT) cuboid([0.2, 0.4, 0.1], anchor=TOP, $tags="remove");
}

from Revar Desmera:

The attach() module by default overlaps the attached with the parent by a slight amount (0.01). You can do attach(RIGHT,overlap=0) for an exact alignment.
The overlap is so that CGAL correctly can union shapes.

and the attach() documentation :

Attached objects will be overlapped into the parent object by a little bit, as specified by the default $overlap value (0.01 by default), or by the overriding overlap= argument. This is to prevent OpenSCAD from making non-manifold objects. You can also define $overlap= as an argument in a parent module to set the default for all attachments to it.


Ender 3 Y Layer Shifting My school started a robotics club this year and one of the teachers gave us an Ender 3 printer to use, they assembled it the year before but never actually used it so it was sitting in their garage, I attempted to print several different objects but all of the larger ones seem to suffer from layer shifting on what seems like the Y axis. I've looked at other threads and tried stuff such as changing the binder clips (add adding more), leveling the bed (again), tightening the belts, moving the print position to a corner, using a different slicer, and reslicing the models which all fail, when I print smaller objects, it prints fine. What could the problem be and what can I do to resolve this? I'm using Cura 4.4 currently.

Failed print:

What it should look like:

Successful print (smaller object):

Edit: I'm also using OctoPrint on a Raspberry Pi for remote control but the issue still occurs when printing from an SD card.

Fixed it finally, seems that the X axis was not level. Thank you to everyone who commented.


Music from the printer? Harking back to the days of "singing disk drives," I am wondering if anyone's written music to be performed on a 3D printer. Most of us have noticed in passing that the servo motors for X and Y drive generate a different pitch depending on motion speed. With some care and experimentation, one could write g-code to produce not only a tone but even a 2-tone chord.  So -- has this been done? Does anyone want to do so? (Note that there's no need to simultaneously produce a print, but that would be even classier).

Yes, it has been done before, see here and here.

The README file of the first repository linked above contains a detailed explanation of the basic idea/calculations involved.  A short excerpt:

  As you can set the parameters of G1 in such a way as to precisely control the velocity and the distance of a movement along a certain axis, you can control the operation frequency of the stepper motors as well as the actual time to complete a movement.

On another note (pun intended), you can also play music by using the code M300.


Extruder temperature failure I've never made solid prints since I purchased a TEVO Tarantula in December 2019, but since I'm totally new to this sport, I didn't realize I had an issue until after many failures.  I kept upping extruder temperature and nothing seemed to change, parts printed but fell apart.  Using a hand held temperature gauge to check bed and extruder (on the sensor screw), bed temperature was perfect, extruder only warm, stepping 10 degrees Celsius at a time (200, 210, 220, 230, 240, 250 °C) always resulted in 18.3 °C/65 °F

I looked for broken wires on extruder heat and sensor, but they were okay. TEVO support thinks it's a sensor problem, but it won't arrive for 1 month or more. I purchased a spare extruder from AliExpress when I bought the machine and replaced the complete unit but now I get an error E1 Heating Fail, Printer Halted.

The first extruder unit appears to have an error the firmware can't detect, which is why TEVO thinks the issue with that extruder is the heat sensor. If the sensor's reading hot relative to actual temp, the block will be too cool to reliably extrude, while the printer won't think anything's wrong and won't try to heat the block more.

However, I'm surprised the extruder can push any amount of any type of fil through the nozzle at room temp, which makes me think there's also some user error here. Non-contact temp gauges like IR guns can be bad at accurately checking very localized temperature; I'd recheck the extruder at what the printer thinks is working temp, but use a contact thermometer like a multimeter with a thermocouple (the Extech MN35 is inexpensive and works well for most hobbyist uses).

The second extruder has a detectable error. Either the sensor is again faulty, but this time reading 0 V (which usually equates to 0 °C), or the heating element is faulty and can't warm the block. Either way, the printer can command as much extruder heat as it wants, the sensor never gets above room temp much less to operating temp, so the printer eventually gives up and tells you there's an extruder heating problem.

This printer-detected heating error is a little easier to troubleshoot because the printer can help you. If the hotend gets to working temp as measured externally, but the sensor reads well below it, the sensor is the problem. If the hotend does not heat, or heats very poorly (like only getting into the 150-ish range when trying to heat to 200), it's the heating element. Both the heater and sensor could be faulty, but the combination of two failures is less likely by simple probability, and it's easier to diagnose the sensor issue with a working heater, so if the heater's not heating, fix that first.

It's possible, even probable, that a combination of parts from the two extruders will give you a working hotend, however you have to know which parts are working, and those parts have to be separable (as in you can remove the needed part from one assembly and put it in the other without destroying the part or either assembly), which at this pricepoint is honestly not a guarantee. The info provided in the question isn't quite enough to say which pieces of each assembly should be combined to give you a working extruder head, but the above tests will tell you.


Printrbot going off axis when initializing I have a strange problem with my Printrbot Simple Metal.

When I start printing it's suddenly trying to go off axis before starting to print. All is fine once it actually starts to print, but it's very annoying to hear the sound on the start and end of each print.

That can't be good on the motors and chains either, something is going to give out at some point.

Here's what that sounds like: YouTube - IMG 5600.

My OctoPi settings are:

It is very common that FDM 3D printers "home" their position at the start of each print (as defined by the slicers preprint g-code). This is done by deliberately running the end effector towards its expected X=0, Y=0 position until it hits the endstop switches for each axis. Could it be this behaviour you are seeing? If so, I would suggest checking that your endstops are functioning correctly.

You can manually activate this homing action using the G-code G28 in (for instance) Pronterface. Alternatively, you can verify that your endstops are actually working using the M119-command while pressing each switch manually.


single point z-correction after 3-point auto-leveling On my Monoprice Delta Mini, autoleveling is performed based on three push buttons, on which the printer platform rests: The nozzle moves downwards until one of the buttons detects being pushed down. Using the G29-gcode, this is performed automatically at three points close to the locations of these sensor buttons.

However, even after this calibration, the printer expects the platform at one of the test points to be lower than it actually is. Thus, when printing close to the front right sensor button, the printer "smears" the plastic onto the platform. At the other locations, the printing works fine. Therefore, I cannot simply adjust the overall z-distance. (Multi-point auto leveling gives even worse results since the platform tilts during the probing.)

Is there a gcode-based option to modify the z-height of just one of the calibration points of the autoleveling?

Edit: The bad leveling seems to be a common problem of this printer:

https://www.reddit.com/r/mpminidelta/comments/73xcxg/leveling_doesnt_seem_right/

https://www.reddit.com/r/mpminidelta/comments/6tqe7f/follow_up_on_bed_leveling_issue/

Till now, nobody seems to have a solution.

There is no "standard" g-code, especially for the auxiliary functions of calibration, and even more so for the calibration of delta-class printers.  I find that the Reprap Wiki includes a fairly comprehensive list: http://reprap.org/wiki/RepRap_Firmware_G-Codes and http://reprap.org/wiki/G-code.  These lists address the RepRap firmware, although they include some g-code functions which are specific to other types of applications.

If the Monoprice Delta firmware is based on the RepRap firmware, the lists might be helpful, although detailed documention from Monoprice would be the best reference.

Assuming there is no available or known g-code to adjust this, you work from the hypothesis that your three switches are not responding identically.  If possible, use a micrometer to measure the difference between the "idle" position of the bed and the point where the switch actuates.  It could be that the front switch requires more travel before actuation, which would then cause the leveling calculation to have a lower point for the front switch.  In the alternative to measuring, it may be possible to exchange the front switch with a rear/side switch and see if the problem moves.

Delta machines are more difficult to calibrate because everything interacts.  The three actuator delta machine is a simplification of a more complex 6-axis Stewart platform.  As I see it, a delta machine is a 6-actuator machine in which pairs of actuators operate "identically", except that minor variations cause unexpected positioning errors.  Sometimes these are modeled as a bowl shape with positive or negative curvature, although measurements I've made on my home-brew delta show an error that looks more like a carpet in a high wind.  Some factors improve the design, such as longer actuator arm pairs and smaller build diameter, which may help you with the Monoprice.


How to turn off supports in Z-Suite (Zortrax slicing software) I would like to print a model without supports on the Zortrax M200. To do this it is mandatory to use the proprietory Z-Suite slicer. I am certain that at some point I found an option to turn off support struts (I specifically remember the text "(not recommended)" appearing in the UI somewhere), but it seems not to be there now. Is my memory playing tricks on me, or is there a way to enable a "no supports" option in Z-Suite?

I've found the answer for myself by playing around a bit more. It seems that in selecting the "support angle", a higher angle means more supports. This was confusing me, because I had assumed "support angle" meant the maximum angle of overhang before a support would be generated. I guess it does actually mean that, but it counts 90º rather than 0º as vertical. In any case, supports are turned off simply by changing it to 0, in which case the text "not recommended" does indeed appear.


How to offset my probe so it's not hanging off the bed at 0, 0 position when printing I had my printer printing fine when using the stock trigger switch as I used it to print the green bracket you see in the picture.

My problem now is when I do a print with the sensor, it moves to 0,0 position. However in this position the sensor is hanging off the bed hence there is nothing for it detect so it crashes into the bed.

As far as I can tell the nozzle is homing in the right place.

How do I tell Marlin the new minimum position it needs to be in so it doesn't crash into the bed?

It is not a problem that the sensor is not above the build plate during printing as long as it is above the build plate during the auto bed levelling sequence.

Homing does not necessarily need to be the (0,0) coordinate. Usually, a printer homes on the endstop switches, from that coordinate an offset is defined in the firmware to move to the origin. This implies that (depending on the position of the sensor), the sensor may be outside the bed area when the nozzle is at the origin (0, 0)). Therefore, similarly, you need to tell the printer the location of the Z sensor with respect to the nozzle position in order for the printer to keep the sensor on the bed when levelling by setting boundaries for the sensor to reach.

E.g. for Marlin firmware the offset from homing to the bed origin is defined for an Anet A8 by:

#define X_MIN_POS -33
#define Y_MIN_POS -10

The values you should use need to correspond to the actual offset from the homing point to the origin of the bed (0,0).

When using an auto bed leveling sensor like you are using you should consider this remark:

  If using a Probe for Z Homing, enable Z_SAFE_HOMING also!

Un-comment the proper line in the configuration file to read:

#define Z_SAFE_HOMING

This will make the printer aware of the sensor, and home Z in the middle of the bed (default behavior, but can be changed), so that your sensor is never off the bed when probing the bed for Z homing.

Furthermore, you need to set the offset values of the center of your sensor to the nozzle center:

 *   Z Probe to nozzle (X,Y) offset, relative to (0, 0).
 *   X and Y offsets must be integers.
 *
 *   In the following example the X and Y offsets are both positive:
 *   #define X_PROBE_OFFSET_FROM_EXTRUDER 10
 *   #define Y_PROBE_OFFSET_FROM_EXTRUDER 10
 *
 *      +-- BACK ---+
 *      |           |
 *    L |    (+) P  | R <-- probe (20,20)
 *    E |           | I
 *    F | (-) N (+) | G <-- nozzle (10,10)
 *    T |           | H
 *      |    (-)    | T
 *      |           |
 *      O-- FRONT --+
 *    (0,0)
 */
#define X_PROBE_OFFSET_FROM_EXTRUDER XXX   // X offset: -left  +right  [of the nozzle]
#define Y_PROBE_OFFSET_FROM_EXTRUDER YYY   // Y offset: -front +behind [the nozzle]
#define Z_PROBE_OFFSET_FROM_EXTRUDER 0   // Z offset: -below +above  [the nozzle]

Where XXX and YYY are your actual values.

And set the boundary of the probing section:

// Set the boundaries for probing (where the probe can reach).
#define LEFT_PROBE_BED_POSITION 15
#define RIGHT_PROBE_BED_POSITION 190
#define FRONT_PROBE_BED_POSITION 15
#define BACK_PROBE_BED_POSITION 170

Note that the values should match your bed size!

And:

// The Z probe minimum outer margin (to validate G29 parameters).
#define MIN_PROBE_EDGE 10

Details on setting the boundaries of the bed to keep the sensor on the bed is described in question "How to set Z-probe boundary limits in firmware when using automatic bed leveling?".


Is the 110 m length accurate for 3.0 mm 1 kg spool? I've been seeing the 330 m and 110 m length estimates for 1.75 and 3.0 mm spools (of PLA, presumably). But a moment's thought staring at that will raise an obvious question.

Using πr², we get the area of the filament in square millimeters (rounding to two decimal points)

For 1.75 it's 2.41 mm²

For 3.00 it's 7.07 mm²

Then taking the ratio and multiplying:

(2.41/7.07) * 330 m = 112 m which is close enough to 110 m.

BUT as all makers of filament and makers of extruders know, 3.00 mm is just a rounding off of the real dimension, which is 2.85 mm. Now do that:

For 2.85 it's 6.38 mm²

and:

(2.41/6.38) * 330 m = 125 m which is at least 120 m.

So, whoever calculated the approximation of 110 m did the calculation based on the rounded rather than actual dimension. What am I missing here?

My point is not that the 330 and 110 would be inaccurate given the dimensions of 1.75 and 3.00. Rather, my point is that the 3.00 mm diameter is not what is really so; it's actually 2.85 mm and therefore the answer is longer than 110 m.

Let's go about this scientific:

$A_r=\pi{r}^{2}=\pi{\frac{d}{2}}^{2}$

As a result the crossections are $A_{3}=7.06858\text{mm}^2=0.0707\text{cm}^2$, $A_{2.85}=6.3794\text{mm}^2=0.0638\text{cm}^2$ and $A_{1.75}=2.40528\text{mm}^2=0.024\text{cm}^2$.

Volume of a cylinder is $V_{A_d,l}=\times {A_d} {l}$. Turned around to get a length from Volume and Area we get $l=\frac {V_m}{A_d}$, but what is V?

We know the density of comercial PLA is about $\rho=1.25 \frac{\text g}{\text{cm}^3}$, and we know $m=\times V \rho$. So: $V_m=\frac{m}{\rho}=\frac{1000}{1.25}\text{cm}^3=800\text{cm}^3$.

Taking this Volume and using the $l=\frac {V_m}{A_d}$ we get:

$l_{d=1.75}=33333.33\frac{\text{cm}}{\text{kg}}=333.33\frac{\text{m}}{\text{kg}}$

$l_{d=2.85}=12539.18\frac{\text{cm}}{\text{kg}}=125.39\frac{\text{m}}{\text{kg}}$

$l_{d=3}=11315.41\frac{\text{cm}}{\text{kg}}=113.15\frac{\text{m}}{\text{kg}}$

If the filament is more on the dense side $(\rho>1.25\frac{\text g}{\text{cm}^3})$, then it will have a smaller volume and thus be shorter than this estimate.

To show this better, a graph: This is the length of a filament spool in dependancy of the density. The values were calculated for the usual diameters with their closest neighbors rounded to 0.1 as absolute diameters and run over a broad range of densities commonly used in plastics - 0.7 g/cm³ to 2 g/cm³.


Ender 3 Extruder Speed / Upgrade I am attempting to make my Ender 3 Pro print significantly faster than it is intended it I fear.
I hear a clicking noise coming from the extruder above 130 mm/s in Cura when it is going in long straight lines (I think my acceleration settings prevent it on shorter lines).  I have seen this before when the bed is too close to the nozzle but I have auto bed leveling now and it is happening on all layers.
I have a standard extruder + Bowden tube setup.  What can I do to make things go faster?  I am less concerned about the quality of the print and more concerned about the speed.

I am still somewhat of a noob, but I have heard that your problem may be because the extruder is not getting the filament out fast enough. You are trying to extrude filament before it is sufficiently fluid. Try increasing your hotend temperature by 5 degrees.


What is causing 'droplets' on first layer? I recently changed filament and for starters it worked perfectly well, but quickly I got some problems with my first layer. It's like droplets are forming on the surface (finished item + 3 undersides):

The final part is (for me) okay but I'd like to get rid of those pesky 'drops'.

As the defect is quite stable and quite recognizable and it happens all the time, I bet somebody more experienced than me knows what's going on!

Info:

I'm using a 1 week old eSun filament, a E3D V6 Hotend 1.75mm on my scratch CoreXY printer, short Bowden direct drive, Repetier, Marlin, Linear advance (M900 K60 so quite low).

The print is done using a 0.4mm diameter nozzle at 0.2mm height at:

50°C(122°F) heat-bed and 214°C(417°C) hot-end for first layer, then lower a bit to

40°C(104°F) heat-bed and 211°C(412°F) hot-end.

I use Blue-painter tape.

Worked perfectly well with my black eSun and my white eSun.

What's my problem?

Thank you all!

[Edit]

Tried about everything (more temp, less temp, fan on item, more / less bed temp, underextrude, moving around z delta, removing linear advance, radically lowering speed) but the only thing that worked about okay (problem was quite reduced but didn't go away totally) was to bump up the layer thickness to 0.3mm

[Edit 2] Finally it seems it was, as it usually is, a conjuncture of several problems that I will list here:

The bed was not perfectly flat
The heatbed moved/bended when going from a hot first layer to a colder second (and on) layer
Maybe the speed was a bit high for the first layer (25mm/s)

I fixed this by installing a borosilicate glass bed on top of the heat bed which ensures a perfect flatness.

I had to change my inductive sensor to an 8mm one (insteéad of the 4mm I had previously added) to make this function. I think it is not as good as it can be as it detects the heatbed under the glass (which is not perfectly flat), but it's enough for now. I'm thinking about how to make the glass conductive, like aluminium or something, but that's for another day/post.

I also put blue tape on the glass because the first layer was tricky. This might be because the inductive sensor doesn't do its job that well (see above).

Heatbed temperature for first layer: 70°C

Extruder temperature anywhere from 190°C to 220°C works fine, that was not the problem, or it is no longer a problem.

I also lowered the first layer speed to 20mm/s because the first layer didn't stick easily directly onto the glass, with blue painters tape it sticks even too much so I'll try higher speeds. It did mitigate problems though so it might be a path to try if you run into similar problems.

And now it seems that it works even amazingly well, I just have to print something really big to see!

---------------Old:

Moving z up made spaghetti :-) and different temperatures made quite extreme warping:

Mine is more of an educated guess than a definitive diagnosis, but it looks to me like if your printer may be overextruding (it's difficult to say with certainty with this particular picture, but your top layers too do not look as good as they should).

I wonder if you have calibrated your extrusion for this particular spool of filament?  This is something that you should do for each and every new spool of filament, regardless of whether you have already used the same brand and material, as different batches and colours may differ slightly in diameter or hardness, and both factors can lead to a different overall flow out of your nozzle (I just checked eSun website, and they state "Accuracy:1.7-1.8mm", and 6% variance is quite a lot).

Possibly unrelated, but 211+°C is also quite on the high end of the correct temperature for printing PLA (if that is what you are using).  Still in the range recommended by the manufacturer - so it should be ok - but you may wish to try bringing it down a notch (205°C perhaps?).


Define coordinates for Z homing I have a printer with the following dimensions: L300 x W300 x H400. After flashing Marlin software, the extruder keeps homing at X77 Y50 instead of X150 Y150 that is the center of the printing area for me. Where can I find the appropriate line in config file in order to edit it with preferred coordinates. Unfortunately I can only find info on how to change offset of origin point. In my case origin point is correcty set.

If you enabled Z_SAFE_HOMING, then automatically the printer homes Z at the middle of the build plate, if the bed size dimensions are correctly defined (in your case X_BED_SIZE and X_BED_SIZE should be defined as 300).
In Configuration.h you can find:
#define Z_SAFE_HOMING

#if ENABLED(Z_SAFE_HOMING)
  #define Z_SAFE_HOMING_X_POINT ((X_BED_SIZE) / 2)    // X point for Z homing when homing all axes (G28).
  #define Z_SAFE_HOMING_Y_POINT ((Y_BED_SIZE) / 2)    // Y point for Z homing when homing all axes (G28).
#endif

If Z_SAFE_HOMING was enabled, and the bed properly dimensioned, it could be that the steps/mm are incorrectly defined.
Note that if a probe is used, the offset of the probe to the nozzle center is taken into account, this implies that the probe is moved to the center, not the nozzle. The code responsible for this is found in G28.cpp:
/**
 * Move the Z probe (or just the nozzle) to the safe homing point
 * (Z is already at the right height)
 */
destination.set(safe_homing_xy, current_position.z);

TERN_(HOMING_Z_WITH_PROBE, destination -= probe.offset_xy);

I.e. the ternary operation (TERN_) determines the addition of the probe offset.


Connecting my OctoPrint to a Google drive folder Is there a way where my upload folder on my OctoPrint server would be a folder on my Google drive so that I could save my G-code that was generated using Simplify3d to an existing folder on my desktop at which it would then automatically be uploaded into my RPi via the internet.

Or maybe a watched folder that can be accessed via internet?

You could mount your google drive using gdrivefs on your pi following this tutorial: https://www.raspberrypi.org/forums/viewtopic.php?t=109587
However, I have to ask: why send the file to the internet? Is your printer/pi on a separate network than your desktop where you are slicing?

If they're on the same network, you'd be better off setting up a samba share on your raspberry pi (https://www.raspberrypi.org/magpi/samba-file-server/) and then mounting that directory from your desktop (https://www.techrepublic.com/article/how-to-connect-to-linux-samba-shares-from-windows-10/).

In either case, you could set the directory (the gdrive directory or the samba share) as the watched folder in octoprint's config.yaml (http://docs.octoprint.org/en/master/configuration/config_yaml.html#folder).


What makes 3D printing noncompetitive for medium production runs? I've been 3D printing as a hobby for a couple of years now, and have always heard how 3D printing is great for prototyping, but once you get beyond 10 or 20 pieces it's just not cost competitive with other technologies.  I just accepted this to be truth, and have even told some of the customers I've gotten through 3DHubs and other marketplaces the same thing.

Now I'm creating an item for resale and am 3D printing the case.  As I'll need 40 - 50 cases at a time I thought I would shop around for other options.  But I just received some quotes back on injection molding.  The mold price (for half the case) was \$15k, plus \$10 per unit at a quantity of 50 and \$4 per unit at a quantity of 500.  Even in the case of the latter, the cost of tooling plus production is \$34/piece.  3D printing the same part myself costs $7 in filament, and paying someone else to 3D print it cost \$28.

Keeping in mind that 3D printing allows me to make changes to the design on the fly and print the exact number I need without having to worry about volume discounts, I now wonder if I've just been repeating a common misconception.  Is 3D printing really noncompetitive for medium (10-500 pieces) production runs?  If so, what makes it noncompetitive, given the extremely high up-front cost of IM?

TL:DR

3D printing is great for low quantities of items, but terrible for large quantities of items.  This is a continuous scale and as your quantity grows, the drawbacks of 3D printing become more pronounced.  In your situation, you seem to be dancing in the nebulous zone where there isn't really a good answer as to which production method is better.  It's more of a question of price vs speed.

There are several factors that limit additive manufacturing technologies (in this answer I'll just talk about FDM since you're asking about a plastic item) from being practical in large scale manufacturing.

Time

Compared to injection molding, 3D printing takes a very long time.  An injection mold can make 72 plastic caps in 3 seconds.  While I don't have a source, I would expect a similar item to take at least 5 minutes to be printed.  In order to produce an average of 24 caps/second, you would need 7,200 3d printers working without down time.  That doesn't take into consideration ...

Labor

Every 3d printed object needs to be removed from the print bed by hand.  That requires a person to be there ready to remove the item.  It's possible to have automated print removal, but for now I've yet to see it as a standard option on any machine.  An injection model machine can just pop the parts out into a box.  Even with the capability to remove the parts extra labor is still required for 3d printing because ...

Quality

Injection molded parts are as smooth as the mold they were made in.  While failures still exist even for molded items, their relatively cheap production cost and very quick production time ensure that an occasional failure won't be problematic.  3D printing on the other hand is still prone to variations in the final product.  For a few items, it's sensible to hand finish the parts with filing, sanding, or other reductive manufacturing techniques, but for many items this quickly become burdensome. Also, given the long production time compared to injection molding, even 1 discarded product will result in a long time required to produce a replacement.


How to remove exess filament from bed after removing model Recently got an Anycubic I3 Mega Printer and I've been playing with what it can do, but after a model is done it leaves residue on the build plate behind that is bugging me. Do I NEED to remove it? If so, how? Thanks! (I'm using PLA if that matters)

My Problem:

You should remove it because it can and will affect the quality of future prints. Residue can mix up with new filament and create a ugly of colors and also prevent adhesion in places, thus potentially ruining your next print.

You have several solutions to clean up the bed:

Scrape it off: usually works, but you risk chipping the surface if you're not careful or if you stumble upon a bit of residue that is stubborn and you need to apply strength to get rid of it. I think a scraper is included with the printer.
Sponge and soap: Since the bed cannot be removed, as far as I can tell, you'll need to make sure that the sponge isn't dripping or put towel paper around to avoid damaging the components below, including the heating unit. Rub it gently on the residue until it soften and detaches. It might take a bit to work.
Yellow glass cleaner from Karcher: my favourite, the one I use on my printer and it never failed me. Spray it on a cloth or something, and rub it on the bed until the residue softens and detaches. It might take a bit to work, but you don't run the risk of dripping liquid on any component, and it works way better than soap and without the risk of chipping the bed like when you use a scraper.


Filament jam on the tube entrance I have a problem in regards to filament jam, however I don't think that my case is any related to the extruder nozzle.
After 30 to 40 minutes printing my filament bends and get stuck on the tube entrance.
To print a nut wheel which comes as a demo file, I had to repeat the operation 4 times, and I had to stop printing when it got stuck, and continue with the printing, which led to a small imperfection.
What's the problem? The filament? The printer? Myself?
I have a Voxelab Aquila (completely new) and the filament u just a generic PLA from Amazon.

Something is stopping the filament from going down the tube 30 to 40 min. after you start printing.  You are correct that this doesn't sound like a clogged nozzle.  It could be deformed filament, but the closeness of the timing after the start sounds like heat creep.  Other possibilities are also listed at the linked stackexchange article.
Note: with heat creep the filament will not jam in the tube.  It will jam just above the nozzle on a Bowden tube extruder; thus the filament stops going down the tube.  The tube entrance is probably the largest location the tube can kink, although not very large.
What are ways to avoid heat creep?


How to draw cube with cone (Dreidel like), using Onshape? I want to draw a cube with cone using Onshape.

I need the cone to "shave" the corners of the cube, till it gets to the middle point.

This is diagram I made:

What is the best way to do it?

After rejecting the intense interrogation process for signing up with Onshape, I've settled for a general description based on common practices in 3D modeling.

You would create the rectangular solid representing the cube, as well as another rectangular (or cylindrical) solid slightly larger than the first one.

Create also a cone shape with the dimensions appropriate to the segment you wish to have remaining on the first solid.

Using Boolean operator or the equivalent, subtract/difference the cone shape from the second solid, resulting in a "pencil point" shape of empty space in the second solid.

The skirt of the cone is barely visible in the image above and is transparent, the TinkerCAD™ version of subtraction.

Once grouped in TinkerCAD™, the entire cube becomes a subtractive body.

Place it in the appropriate position over the first solid and perform a second subtraction/difference or Boolean equivalent.

As one may note, the original cube was not tall enough and had to be stretched to provide the desired result. Not visible in this image is that the subtractive shape was not centered on the cube and resulted in an off-center final solid. Easily corrected with alignment tools, but an important aspect when performing Boolean operations. Control-Z is your friend.

The above steps work with OpenSCAD™ as well as Fusion360™ and even within TinkerCAD™ but the specific steps/sequence varies from one program to the other, of course. This example was performed in TinkerCAD™ because it was the fastest method. Fusion360™ would have stretched my abilities to accomplish the same result, due to my minimal experience with that platform.

I am not surprised to discover and easily locate an exact tutorial for OnShape™ that covers the boolean subtraction process. The images are complex within the tutorial, but the process and concepts are identical. The video accompanying the tutorial is also well done and explains clearly the steps involved.


What does the trimpot on my Switching Power Supply do? On my Switching Power Supply there is a little orange trimpot that's marked VR1; what does that do, and does it work similar to the ones on the stepper drivers?

No doubt it's just a final tuning potentiometer. Even on the pictures you linked it's described as V adj which stands for voltage adjustment.
It's a way to tune your power supply's output as it can vary depending on temperature/humidity/wall-plug voltage/etc.

It's usually set properly and doesn't need to be touched. But you can connect a multimeter to check if your power supply gives the voltage you need.

If you are not familiar with the subject but still want to do it yourself, it's good to set your multimeter to the highest available range and make sure that AC/DC is properly chosen.  Now you can measure voltage. You can set the range closer to the expected values then. Usually multimeters have a range around 20 or 30V DC which is propbably what you expect from your power supply. In such a range you should see something like 12.000. If it varies from 12.000 you can then precisely adjust it to get as close as possible to this value. But watch out... cheap power supplies can cheat you. When the are have a load on the output (your 3D printer for example) they can reduce voltage.


Robotdigg linear guide not smooth motion I recently bought the MGN12H linear guide and rail from robotdigg, which is supposed to be the copy of the Hiwin.
I have noticed that the motion is very smooth when moving fast, but if I move it very slowly, it gets stuck and the motion is not smooth at all. I think this will cause problems on my prints once I assamble the printer.
Am I missing something? Should I put some king of oil on the balls?

Difficult to say with the given data, but here are a couple of ideas:
First theory:

The belt is too thin/flexible for the linear guide.

Linear guides remove the backslash by adding quite some pressure in the ball system: The block is slightly too small (compared to the rail) and thus it compress the balls and rail. The backslash is avoided until you reach this force.
This pressure require a little bit of force to move the block along the rail, so if your belt is too thin or flexible, the belt will start to move until the elasticity of the belt reach the force required to move the block, then the block move a little bit and stop again.
In a fast movement, your block never get to stop, while in a slow movement, it has time to start and stop. Maybe what you feel like "not a smooth movement"
If you identify this case, I suggest you the following solutions:

Lubricate correctly the guide, this could be enough to reduce the issue to an acceptable level.
Change the belt to a larger one, with fibre glass inside (not only rubber).
If I am correct, the "H" of your MGN12H stand for the pressure of the block. H is for high pressure, switching to a C is far enough for a 3D printer and will reduce the drag.

Second theory: (Thanks to FernandoBaltazar)

You got some dust, rust inside

Remove the belt and move the block with the hand, if you are able to feel the movement is not smooth, then it's probably this case.

Add some grease (Never in your life use cooking oil)
Clean the dust of the rail and exterior of the block
Move the block from one side to the other of the rail until the movement become smooth.


Re-homing Z: trouble resuming a print, what if I can't re-home? Running Marlin 1.1.2, printing from Octoprint on Linux PC. So, the PC freezes up and I have to pause the print and reboot. It's a 36 hour print with 11 hours left to go and I'd rather not start over.

I have the X, Y, and Z coords of where I need to begin again, and I've deleted all the GCode to that point. In the several tutorials I read on how to resume a print, they all assume that the printer - which in my case had a restart of its own - knows where Z is. I can safely rehome X and Y, but when I try to rehome Z the print head moves to the center of the plate, which of course would cause a collision with the model.

On my printer the Z-axis switch is over to the side of the frame holding the print bed, so I can home Z with the print head anywhere. Is there a way I can home Z without the head moving to center? Or, barring that, some offset I can enter for Z so I can resume at the same height I started? I can't wrap my mind around what I need to do here.

Was able to make it happen, though I fear that I may have misjudged exactly where zero was, but we'll see in a few hours.

Anyway, for those who may come along later, here's what I figured out:

I already knew what my X, Y, and Z positions should be.

I kept the heat on for the bed so the print wouldn't shrink and break loose.

With the plate lowered and the print well out of harm's way, I homed X and Y. Then moved X10 Y0, a convenient place to work.

I set relative positioning on, G91, and moved Z up toward the print head until a business card was firmly clamped between the head and the plate.

I then set Z at zero, G92 Z0. Apparently Marlin (or Octoprint? idk) will let you print without homing Z as long as it knows where zero is.

I moved to print head to my desired X, Y, and Z positions and checked it against the model, which seemed to be right. I fear that I may have not zero'd down enough, so there will be a noticeable gap/weak spot, but I won't know that until I get more layers on than there are at this moment. I suppose if that's true, then I could just shave off the new layers and reset zero a couple of layers tighter.

The rest of the steps for resuming a print (editing the G-Code and what-not) are readily available in a dozen or more tutorials, so I won't cover that here.

Follow-up: yep, left too much room. I shaved off the new layers (having a kiridashi really helped there) and re-zero'd, but this time, after doing so I entered my initial Z value so that the nozzle touched the model and adjusted from there. Note that aesthetics aren't an issue: these are mechanical parts to all they need is to not snap in the middle. Having a seam there isn't a problem.


How to calculate linear Y rod length for a larger replacement bed? I have an Anet A8 which I want to convert to an aluminium frame printer like the AM8 (rebuild of Anet A8 parts):

This should give a much more stiff frame with respect to the acrylic frame to aid in a better print quality.

Since the bed (220 x 220 mm) has a slight warp, I want to use a larger build platform (200 mm x 300 mm) I have laying around. My plan is to use the 300 mm in the Y direction.

Knowing the maximum outer distance of the current Y bearings to be 105 mm, is that too short for such a large bed?
How do I calculate the length of the Y axis rods? (especially if you take another distance than 105 mm)

Basically, your setup is the following:

The overhang of the bed, assuming the bearings are in the center, equals (300-105)/2 = 97.5 mm on each side. So the distance from the leftmost bearing face (when bed is at y = 0 mm) to the center of the Y rods assembly equals 300 - 97.5 = 202.5 mm. Knowing this distance for the other side of the center to the right when y = 300 mm is the same, the minimum length of the rod will therefore be 2 x 202.5 = 405 mm which equals the addition of the bed length and the outer bearing distance 300 + 105 = 405 mm.

Please note this excludes extra length for e.g. a limit switch, and some extra space around the bed. Basically the extra length of the bed 300 - 220 = 80 mm needs to attributed to each side of the bed, so 40 mm on each side extra.

For a 220 x 220 mm bed, the minimum length would be 2 x (220 - (220 - 105)/2) = 325 mm. When I measure the rods between the acrylic flanges it measures about 365 mm, about 40 mm extra for clearance around the bed (20 mm on each side).

The overhang for the 300 mm bed is not that much, and a construction under the heated plate will be used to fasten the bed at the corners, as long as that construction is not to flimsy, the current distance will be alright. For other distances you should change the value of 105 in the formulas above. E.g. for an outer flange distance for the bearings of 120 mm, you would require rods of at least 420 mm.


Ender 3 v2 printing problem Last week, my printer worked really well, but after a print it started having some printing problems. The printer stops extruding mid-print or under extrudes.
After this happened, I

leveled the bed again
increased hotend temperature from 200 to 215 °C (PLA)
changed slicer (I was using Ultimaker Cura), now I'm using Creality slicer
changed the transmission ratio 93 to 106 according to this video

After making adjustments according to the video, the printer still stops extruding mid-print or under extrudes. What should I do to fix this?

One common reason for extrusion to stop in the middle of a print is heat creep.  See What are ways to avoid heat creep?


Stepper does not move smoothly I have a problem with the y movement of my machine.

When i select y+1 in repetier, it moves, but with a very strange noise.

I have a video to show the problem here

I have:

Set the voltage of the stepper drivers to 0.6V

Set the voltage of the power supply to 12V

Tightened the belts (but not too tight!)

Does anyone know what this is? Is it a problem with my belts or are my stepper motors too weak?

Fixed. One of the two was movign in the wrong direction. Problem solved!


What are the advantages/disadvantages of using synchromesh cables instead of belts? Some 3d printers use synchromesh cables instead of belts. For example, the Deezmaker Bukito (http://bukito3d.com/) and a number of RepRap conversions.

Photo from http://christophergranz.com/?p=449

Are they significantly better than GT2 belts? What are the challenges?

Looking at the specs for both the GT2 belt and the Synchromesh I'm very hesitant to recommend a Synchromesh over a belt.

The first thing that sticks out is that there are both error and cumulative error specifications for the Synchromesh. For a device like a 3D printer, I don't like the idea that of my axes can accumulate up to ±0.16 in. of error over 100 pitches (the pitch is between 0.12 in. and 0.25 in. so that is 12 to 25 in.).

Contrast this to a belt where the only way you have a cumulative error is if you skip a tooth and I think the winner is the GT2.

Looking at the non-cumulative pitch error both products are comparable but again the belt wins. For the Synchromesh we have an accuracy of ±0.002 in. versus ±0.0003(1) in. for a 2 mm GT2 belt and ±0.0012(1) in. for a 3 mm GT2 belt.

Note: I can't be certain about exact values for error since there are no numbers for the GT2 - only a stupid chart. I also have a hard time believing that error is not a function of total length for both the Synchromesh and the GT2 belt but I'm not the manufacturer. However, since both products are made by the same company I wouldn't be as concerned about them trying to oversell one product over the other.

In conclusion, I don't see of any reason to choose a Synchromesh over a belt if your physical layout is compatible with both. As pointed out in the marketing material for the Synchromesh, it can be routed along 3 axes whereas a belt works best along a single axis. The Synchromesh seems to be a product designed for a very specific application...

Sources

http://www.sdp-si.com/PDFS/Technical-Section-Timing.pdf

http://www.sdp-si.com/PDFS/Synchromesh-Cable-and-Attachment-Inch.pdf


How do the E commands in G-code work, exactly? I've tried looking online but haven't quite found the answer to what I'm confused about, exactly. Consider the following 3 lines of G-code:

G1 X129.000 Y126.322 E7.90758

G1 X128.349 Y125.707 F7800.000

G1 X128.476 Y125.548 E7.92045 F1800.000

Does the absence of an E command in the second line mean that no material is to be extruded from line 1 to line 2? As I understand it, the E parameter controls how much material has been extruded up to that line.

The reason why I am asking is because I'm trying to understand on the code level how to identify when a printer will travel without extruding any material, in the case of moving in the Z direction, or if you are printing multiple disconnected parts in one print. Since none of the Z lines seem to have any E commands, I'm inclined to believe that the absence of an E command means that when moving to the given position from the previous line, no material will be extruded. I've tried quite a few different queries online to try to discover if this is the case, but haven't found a simple answer, so I was hoping someone on this board could enlighten me.

Yes, the absense of an EX.XXX (or an EX.XXX with the same value as the previous one) means nothing will be extruded during the move. The extruder is treated as an imaginary fourth axis and works exactly the same as any other axis: if in a G1/G0 no new coordinate for it is specified, it retains its original position.


Heat sensor problems with Makerbot Replicator 2X We have a Makerbot Replicator 2X at our school.  I have a class in the computer lab and one of our focuses is using the printer. Currently, it is not printing properly.  We are using PLA at 210 degrees Celcius.  The built plate is not heated (using Build Tak).  This has worked very well in the past.  The problem is that when the extruder goes to lay down plastic, the filament is too hot and curls up in a clump around the extruder.  This is characteristic of when we first tried PLA at a higher temperature.  I think that our heat sensor is not working properly.  Does anyone know how we can fix this problem?  Is there a way to calibrate the sensor is should we install a new one?

Overall, it is unlikely that the problem is temp sensing accuracy. There are only a few things that will throw off the thermocouple's reading:

Poor thermal coupling between the tip and the hot block, such as if the tip has partially pulled free of the brass thermowell crimp (this will make the hot block hotter than the reported temp)
Loss of electrical insulation between the tip and the hot block, plus some ground loop noise or stray voltage on the hot block (this will typically add noise to the reported temp)

You should be able to visually check for the first, and test for the second with a multimeter. The resistance between the board end of the thermocouple leads and the brass thermowell at the tip should be infinite / out of range.

To actually check the thermocouple calibration, you have a few options:

Easy: Look at the behavior of the printed plastic. PLA that is too hot will smell of pancakes/waffles much stronger than normal, or even smell burnt. The printed material may be more shiny than usual. It will string and ooze more as you print.
Moderate: Secure another reference thermocouple (such as might come with a digital multimeter) tightly to the hot block with some Kapton tape, somewhere the aluminum block is exposed. The external TC should read within a few degrees of the printer's TC. (Assuming you get it attached well enough.)
Hard: Place the tip of the TC in boiling water to check if it reads 100C (or slightly lower if you live at a high altitude). Repeat with well-mixed ice water to check if it reads 0C. Both measurements should be within a couple degrees. You will probably need to dismantle much of the extruder to detach the thermocouple for this test.

But, again, the problem probably isn't the TC. It's more likely either a bed tramming issue (eg too much gap between nozzle and surface) or the BuildTak is degraded and not adhering. This can happen if you do a large number of prints in the exact same place, or get the surface oily, such as with fingerprints. Try a fresh sheet of buildtak or cleaning it with rubbing alcohol and moving the print to a different location.

In some rare cases, low-quality filament or filament stored in very high humidity may not stick well. This is pretty rare though. For the most part, if your nozzle gap is right, any extruded plastic will stick to Buildtak.


How do you program a 3D printer? I'm thinking about building my own 3D printer/Laser Engraver/CNC. Since all use a standard Cartesian axis I wanted to be able to swap out tool heads depending on the purpose. I have everything thought out except the coding aspect of the project.

I currently own a 3D printer and am familiar with some of the coding aspects, gcode, stepper motor moment, axis zeroing, etc; but if I am to build a 3 axis system how do you go about coding it? Are there programs that automatically calibrate all the motors? Can I take existing 3D printer programs and adjust the stepper motor values and build plate area? or do I have to code a new printing program from scratch that can read gcode? For simplicity lets just talk about the printing aspect of the build as I realize that CNC's and laser engravers work on different vector systems. Thanks :)

The foundation of any 3D printer is the controller and the firmware. Many devices are based on Arduino type controllers, with stepper motor driver boards either integrated or added as a plug-in component.

Some manufacturers will use in-house or outside resources and develop their own boards and firmware.

You can search for 3D printer controllers and get a pretty comprehensive list of the various devices available for purchase.  Smoothieboard is one device, Raspberry Pi and Arduino as noted above, and others.

There can be found varying "flavors" of firmware to load onto these controllers as well.

The field is exhaustive.

To address your focus regarding the printing aspect, that's one stepper motor per print head/nozzle (usually) and involves calibrating the amount of filament dispensed from the nozzle per unit steps, or more easily understood, amount of steps per unit of filament movement. My stepper motor for the extruder has a planetary gear and moves 100 mm of filament for about 5000 steps.

All of the parameters you've noted are integrated with the firmware. Motor calibration requires movement per step or steps per millimeter to be entered, unless you purchase a turnkey system with the values loaded.

You can adjust many of the parameters from the slicing software, but it's more practical to determine the calibration settings, enter that information into your slicer and proceed with model management.

Look into instructables for others' build projects to see what they've accomplished and the steps involved in such a build. This can give you a starting point for your efforts.


What are the changes between BLtouch 3.0 and 3.1? I couldn't find a reliable source listing the improvements of BLtouch 3.1 vs 3.0.
I can see that BLtouch 3.0 is sold (original) for about 20 Euro, while 3.1 costs about 30 Euro. The difference is significant.
What are the improvements?

Best reference would be the original equipment manufacturer (Antclabs). It appears their sensor has had many versions:

So, from 3.0 to 3.1 is a software upgrade. Reported highlights are:

★ Smart V3.0 (Mar. 2019 ~ ) : S10, S60, S90, S120, S140, S150, S160,
PWM Wiring defect indication(Blue LED), QR, Molex 1.25, Plastic
Push-pin(PC), Power Wiring defect indication(Red LED)
★ Smart V3.1 (Mar. 2019 ~ ) : S10, S60, S90, S120, S130, S140, S150,
S160, PWM Wiring defect indication(Blue LED), QR, Molex 1.25, Plastic
Push-pin(PC), Power Wiring defect indication(Red LED)

If you look at the manuals you will see the differences:
V3.0

V3.1

As can be seen, timings are different and more PWM position G-code options are available in the V3.1.


Micro 3D filament food safe Before you put duplicate from this Which are the food-safe materials and how do I recognize them? please read

I need to know if this 3D Ink™ (PLA Filament) is food safe

In general, PLA is known as a "food safe" filament, especially Natural PLA. However, filament suppliers have different processes that may detriment the food safe quality.

Doing a little digging, I found an article on the M3D site which mentions the following about their filament

  All of our products, including our filaments are made from 100% non-toxic components and considered generally safe under normal use. They are not considered a chemical, or a hazardous material by OSHA standards. Therefore, OSHA defines it as an "article" and does not require MSDS sheets. You can see more information about that here: http://www.ilpi.com/msds/faq/partb.html#article

So, without contacting M3D directly to acquire an MSDS (or asking if its food safe), you will not find one online.

Here is an article on a few tips for printing food safe objects as well. In a nut shell, don't 3D print food handling objects with crevasses, using uranium, or intend to put in the oven (a.k.a common sense).


Should I Opt For Linear Rails With Belts OR Linear Rails With Ball Screws For A Cartesian Style Printer? I am building a medium-sized printer which needs to produce super-precise parts at a moderately fast print time. I frankly don't want to deal with belts or their tension issues but on the other hand, having ball screws on each axis will increase inertia...right?. I'm using Rexroth rails and will use (depending on what I decide) name brand belts or name brand ball screws.

In many years of building printers I only used ball screws for the Z-axis, and even then only for larger Makerbot and Ultimaker style designs that had a heavy platform.
Even for the Z-axis, a good thick trapezoid screw with the right anti-backlash configuration is often enough because most printers are light and most slicers only print upwards.
Modern belts are also very accurate, and if they are not load-bearing, and you stick to good closed-loop ones, they can be incredibly stable over time.
I tended to base my X-Y configuration around the available sizes of good quality closed-loop belts, and sized everything else to be compatible.


How sensitive are all-metal print heads? So my goal was to print in a variety of materials with my CR10, but all attempts up to now have failed. I've tried a variety of all-metal hot-ends (except Micro Swiss) with no success. For those with a similar Creality printer that successfully print with all metal ends, how sensitive are they? Do they only print with high temp materials? Is a head too close to the bed enough to jam it? Is a 5 mm retraction prone to jam it? Do I need to stick to a premium brand when it comes to all metal hot ends?

Full definite answers on your questions are hard be given, there are a few parameters affecting the clogging of all-metal hotends.

All-metal hotends are considered so-called "upgrades" for printers while in fact they usually cause more problems. For high temperature filaments, like PC and some Nylons, etc. (printing temperature above 250 °C)  you require a hotend that can withstand higher temperatures for prolonged use of the hotend. The problem is that heat creep (heat climbing up the throat/heat break) causes low temperature melting filaments to become prematurely soft and cause problems when retracted.

This requires the printer operator to provide enough cooling air to the coldend of the hotend assembly (usually the part where the cooling fins are) to dissipate heat creeping up the heat break and carefully tune printing temperature and retraction length.

Note that Ultimaker Cura uses quite large retraction values (default 6.5 mm), which work perfectly for the UM3E. This could be closely related to the compression effect of the filament in the Bowden tube. The all-metal hotends from the UM3 are perfectly capable of printing low temperature filaments, so if dialed in correctly, such hotends are not only to be used for high temperature filaments.


Glue for attaching PLA pieces to titanium I'd like to attach a piece I printed out of PLA to a small titanium rod. I've previously used Superglue (cyanoacrylate) to glue PLA pieces to each other with great success, but the problem is that if you don't apply it perfectly cleanly, it leaves very noticeable stains on the PLA.

Can anyone recommend a good glue for this application that won't leave stains like that?

I've been a fan of epoxies for unusual adhesion problems. I found on Amazon a product with titanium in the name, but there's a caution regarding polypropylene plastics.

PLA is not of that family of plastic, which gives it a good chance of success. Epoxy is typically more viscous than cyanoacrylates, giving you a bit more control of the application, but also creating the need for care with "ooze-out."

The big glue company, Gorilla, also makes an epoxy that includes plastic and metal in the adhesion listing.

As PLA is somewhat sensitive to heat, one would consider that fast-cure epoxies generate more heat than slow-cure epoxy, but the amounts you'll be using are not likely to create enough for concern.


Print layer shifting on Alunar M508 Prusa i3 clone [Edit: My specific question is firmware error or standard layer shifting. using 2 different versions of Cura were getting quite different results from the same stl file.]

Per the image below with Cura 15.4 the centered print both shifted to the bottom of the print bed for the first few passes and then did not build the proper internal structure of the bracket. the top loops were then skewed to the top of the bed.  The 2nd print in the corner was using Cura 3.1 and the first few passes like usual skewed off towards the bottom but it seemed to start printing normally after that.  I am trying to determine if it is a hardware calibration issue or bad firmware on the printer. Any suggestions on what's going on would be appreciated. For some reason the image flipped 180° when posting.

Center part completed its print and should be about an inch or so tall. It was not even able to build the internal structure like the 2nd one had started to do. the 2nd one I stopped after about 10 min since it clearly showed different behavior. from the layer shifting links the most likely cause would be over current stepping.

This effect is called layer shifting . Now that you know what it is called you could look at some other solutions fixing this issue; e.g. here, here or here. The answers of this question describe best what is causing this. Usually (most of all the cases) it means that your belts are not tight enough.

An edit of the question shows that the effect happens when a different version of Ultimaker Cura is being used. In such cases you need to check the speeds and acceleration settings. Too high values may lead to skipping steps causing layer shifting. Be sure it is not a mechanical issue, also note that the nozzle does not get caught up by the uneven tape on the bed. In that effect, you may want to look at this unaswered question.


How can I optimize my print for casting in metal? A fellow maker has tried printing a 3D model in clear PLA (<5% infill, 1 or 2 perimeters), burying it most of the way into casting sand, and then pouring molten aluminum. This melts and burns the PLA, and the aluminum takes the space that the printed model used to take.

There's plenty of room for improvement in his process, but I'm asking about what he can do in terms of the 3D printing process to make his prints more casting-friendly.

What print settings are (generally) best for use in this sort of casting?

What materials, if any, would work better than unpigmented PLA? (Must be a material that a typical thermoplastic FDM printer can handle.)

Any other tips or considerations?

Print a two part negative (mold) of your objects.
http://www.thingiverse.com/thing:31581

https://pinshape.com/blog/how-to-generate-a-3d-printed-mold-for-an-object/

Melt and pour wax into the mold. Praffin wax melts at only 37C, not an issue for both PLA and ABS.
Use the wax object for casting, not ABS/PLA/etc.
The mold is also reusable this way.

To prevent the wax from sticking to the mold, something might be applied to the surface. Oil maybe?


OpenSCAD to Flashprint ruins model based on number of fragments I'm trying to print a cylinder with Flashprint. Problem is, that the .stl file i created (with OpenSCAD) is totally ruined once loaded into Flashprint. With ruined I mean the round outline is now with spikes and steps everywhere. And by loaded I mean directly after loading, not even creating the .gx files. The output of OpenSCAD looks fine, also in other stl viewers I tried.

I figured out the problem occurs more when using certain number of fragments ($fn). If its very small, loading works better. But for numbers that make it acutally look like a round circle (eg 50), Flashprint is unable to load them correctly it seems.

It's obvious that its no slicing or printing problem, but simply a loading one, since the shown object (which does not look any round) also prints the way it is shown in flashprint before slicing.

Does someone know a way to load a cylinder with flashprint correctly, or do I have to switch to different software? I already installed some but am unfamiliar with the printer settings which I do not know in detail. I really though a cylinder should'nt be too complex for any 3D software.

Here is the OpenSCAD Code for Cylinder, just create .stl and load into Flashprint to reproduce the Error:

rotate_extrude($fn=70)
    translate([0, 0])
        square([20,2]);

See also this image (tried native cylinder code, problem remains the same however):

Your image is very helpful. I think you might find that the rendering in your slicer is intentionally degraded to minimize use of system resources. The image you see may not be an accurate representation of that which would be printed.

If you wish further confirmation, consider to create the g-code from the slicer and view it in a text editor. An even better option would be to use an online g-code viewer and observe the results of the created g-code.

The image above is the first line of print for a Marvin, showing that the base curves are smooth and clean. Your cylinder should appear in a similar manner, confirming that your slicer is degrading the image.


How does a UV LCD 3D resin printer work? I've been wondering this for a while, and have searched for hours and have found nothing except undetailed explanations and projects.

How does a UV LCD 3D resin printer cure resin exactly? I understand there is an LCD screen, but where does the UV light come from? Where is it placed?

I'm surprised your research hasn't answered your question, as the concept is relatively simple. You have most of the answer in the question. The missing item is a light source. Usually the source is an array of ultraviolet LED modules. There are resin printers that would not be called LCD printers, as they use computer display projectors to generate both the image and the UV to cure the resin.

A rather extensive list of various resin printers can be found at aniwaa.com along with a clear explanation of the technologies.

The image below is courtesy of the link in the previous paragraph.

The light source that answers your question is visible in the third picture. As noted, the LCD panel blocks the light based on the image to be cured. I think the "uses its own light" is somewhat misleading, unless the builder has found a high-UV output LED LCD panel or is using daylight resins and has configured for long burn-in times.