FEA in 3d printed solids I would like to get a pretty accurate method to do finite element analysis (FEA) on my 3d designs considering the infill. I use Autodesk Inventor to design parts but the FEA can only be applied to a solid body (100% infill). Does anyone know software that can convert a 3d design to another but considering the infill so I can use FEA more accurately?

Rhino will let you create a custom lattice structure inside the solid object, this can in turn be used to create infill using grasshopper (an inbuilt scripting tool):

create a standard cell size and apply the lattice,
convert the whole thing to solid,
reimport into inventor


3D printing extruder not warming up I faced some problem with my 3D printer device. It seems the bed warms up without any problem, however, the hotend does not warm up!

Could you please help me identify what the problem is?

I really hope the extruder doesn't warm up as this would be a problem with your stepper motor :)

I'm sure you mean the hotend doesn't heat up. This could be a number of things but i would start to double check the pinout in your code vs the pins on your mainboard and measure if it gives 12v/24v (depending on your PSU) output.

There's a lot more info required to properly help you.
What board are you using?
What OS are you using? Marlin or something else?
Share the relevant code of the OS for the hotend config/pinout
potentially share pictures of your wiring


Isn't using the Extrusion Multiplier like cheating? One thing I never understood is the so-called Extrusion Multiplier (EM) or Flow setting in slicers like Simplify3D (S3D) or CURA.

The description for this setting reads...

S3D: Multiplier for all extrusion movements (...)
CURA: The amount of material extruded is multiplied by this value. (...)

I always believed that this parameter is just an ugly way to fix an underlying miscalculation or misconfiguration, because using it feels like doing a calculation, getting the wrong result and "correcting" it afterwards by a multiplier - isn't that cheating?

But, recently I thought a bit harder about this setting, now I am not sure anymore. One of the main reasons is, that S3D suggests different values for the EM, depending on the type of plastics used, 0.9 for PLA and 1.0 for ABS.

This somehow implies that there is a physical property that justifies the EM, but I cannot think of one because 1 m feeded would lead to 1 m extruded - no matter what kind of platics used, right?

No, the Flow rate or Extrusion multiplier is to compensate for different materials and temperature ranges.
Where does the factor come from?
Let's say we calibrated our nozzle for work at 200°C with PLA, so 100 mm extrusion are correct and want to print ABS. ABS behaves differently and we get bad prints. What is wrong? Well, they do behave differently in the heat, and print at different temperatures. One easily noticeable difference between the two is the heat expansion coefficient.
Now, I had to scrounge through research papers and Material/Technical Data Sheets for PLA, so take that one with a grain of salt. But we can clearly compare the various plastics heat expansion coefficients:

PLA: $41 \frac{\text{µm}}{\text{m K}}$ a TDS
ABS: $72 \to 108 \frac{\text{µm}}{\text{m K}}$
Polycarbonate: $65 \to 70 \frac{\text{µm}}{\text{m K}}$
Polyamides (Nylons): $80 \to 110 \frac{\text{µm}}{\text{m K}}$

Those are just three randomly picked plastics that clearly are printable. If we heat one meter of them by one Kelvin, they'd expand by that length (a couple micrometer). We heat the later three printing materials to about 200-240 K over the room temperature (~220-260 °C), so we'd expect these the materials to expand by the following ranges:

PLA: 6.97 to 7.79 mm (1)
ABS: 14.4 to 25.92 mm (2)
Polycarbonate: 13 to 16.8 mm (2)
Polyamides (Nylons): 16 to 26.4 mm (2)

1 - using 170 K and 190 K temperature difference for its normal print temperature range of ca 190 to 200 °C2 - first: low expansion at 200 K increase, then high expansion at 240 K
You have calibrated your printer for one of these values somewhere in there. And now you get a different filament that has a different color and a different blend or even you swap from PLA to ABS or switch from one brand to another - the result is: you get a different heat expansion coefficient somewhere in that range and you have almost no chance to know it. The heat expansion coefficient, in the end, has an effect on the pressure in the nozzle and this the speed the material leaves the nozzle, which impacts die swell and so the overall printing behavior.
Remember that heat expansion is not the only thing that is happening in the nozzle. Other big factors are for example the viscosity of the polymer at its printing temperature, its compressibility (which depends for example on chain length or embedded fillers), the geometry of the nozzle, the length of the melt zone... they all play a role in how exactly the print gets to come out.
We can sum all those up under a general "behavior in the nozzle" tag, and as a result one gets vastly different flow/extrusion multipliers, like the 0.9 for PLA/1 for ABS in Simplify3D.
Other Factors?
There are also other factors that play a role.
The distance between the extruder and the melt zone and how the filament behaves there are somewhat obvious: A ductile filament can bunch up some in a Bowden tube while in a direct drive there is much less space for that.
The extruder can have an influence depending on the geometry of the drive gear and how much it bites into the filament. The depth of the deformation is again dependant on the hardness of the filament and the geometry of the teeth. Tollo has a great explanation how this has an effect on the need to alter the extrusion multiplier.
gaining the factors
Most of these are determined by trial and error using a factor of 1 and dialing up manually until proper printing is achieved on the machine, then putting that factor back into the software.
As a side note: Ultimaker Cura has (in its filament database) the ability to save flow rates into each different filament, but does initialize all with 100 % default.
TL;DR
It is a way to adjust to the relative difference between the behavior of filaments (using one of your filaments as the calibration) and not cheating.


What does a stand alone "T" index value do? I'm using IdeaMaker for slicing my print objects. IdeaMaker start strings have a >T0< standing alone on one line and then >T1< on the next line. What does this accomplish?

T stands for "Tool" and has its origin in the origins of .gcode being for other automated machine controls. Depending on the machine, everything could be a tool for .gcode, like an actuator or pump or a spindle motor or a drill.

In 3D printers, the T-controlled tool is usually the extruder motor. Convention has it that the indexing always starts at 0, so T0 and T1 are your first and second Extruder respectively. It is the way to choose which tool is used.

As a side note: E is not originally intended for extruders but for the feed rate of lathes.


Self-lubricating 3D printable materials for space Materials used in space need to not outgas significantly

An answer to this question: Would 3d-printed objects outgas in vacuum?

referred to the NASA outgassing database which showed that ABS, PET, and PLA filaments are all fairly low outgassing and suitable for space application.

What I'm wondering is whether there are any 3D-printable plastics that are both suitable for space and also self-lubricating.   Nylon is the obvious printable self-lubricating material, but I believe that it outgasses too much (I don't think NASA has tested nylon filament, at least I can't find it in the database).

My primary interest is in hobbyist-grade, FDM printers but if there are materials that can be commercially 3D printed, that is also of interest.

Any ideas?

Well, I think this depends on your machine.  If you can support extrusion temps north of 350C and bed temps ~150C, you could try PEI:

https://www.3dxtech.com/ultem-9085-3d-printing-filament/

I believe PEI has self-lubricating properties, and has outgassing of ~0.40% TML (PET is ~0.43%).  Of course, most off-the-shelf printers don't handle that sort of temp range.  But then, industrial grade materials are likely to require industrial grade machines.  :)

You could compare other DBs to NASA's as well.

Outgassing DB:  http://esmat.esa.int/materialframe.html

By the way, Nylon has an outgassing aspect >2.0% TML, which is definitely on the high side for vacuum applications.


Connector Suggestion for Extruder and Heatbed On my Reprap-like 3D printer, I routed all the wires to a spot near the base; for the motors, endstops, thermistors, etc, I plugged them all into a DB25 breakout board, and that's working great.

For my Extruder (12v), and my heat bed (16v), I'm using a 4-pin molex connector -- like we used to use for old hard drives and such, and it's working, but it gets a bit hot, and my print bed is having trouble reaching temperatures that it didn't have trouble with before. -- None of the wiring gets hot at any other point, and none of the other connectors get hot. -- The only thing that gets hot is this one molex connector.

I believe the heat is caused by passing too much current through that molex connector. -- I'm curious to know what other connectors might be better suited to this task.  Can you recommend something that's worked well for you, or others?

I prefer not to double or triple up this connector if it can be avoided, so that I can just have one physical connector to disconnect there, and so that I don't end up mixing them up. -- also, being able to easily disconnect it is important (it's hard to work on the reprap if I can't spin it around or turn it over, etc., that's why I'm using connectors for everything).

You might be able to use one of the connectors (Deans Ultra, EC3, XT-60/30, Bullet) that are normally used for RC models. They're made for very high currents. The XT60 connectors depicted below are rated for 60A continuous (well above what you'd need for any heated bed); their smaller XT30 cousins are good for 30A but less commonly available.

(Photo by Mark Fickett)

For your extruder you wouldn't need anything quite as drastic as an XT60, even a simple JST connector would suffice (though if you are going to source XT60/30's for your heated bed anyway, you might use them here as well).

(Wikimedia Commons, Mike Mahoney)


Is there a way to make a watertight model? Is there a spray that may work? This is a specific model for a specific reason. It's shaped like a cylinder and has a recessed bottom. I'm using a Flashforge Adventurer 3 with Flashforge filament. I tried Sunlu silver/silk PLA+ but my Flashforge didn't like it, so I took the recommendation to use Flashforge filament. It worked just fine, but when I put water in it, it has leaks.
I was printing at 210 with a plate temp at 50. Like I stated, I was excited except for the fact that it's not watertight.
Since I'm new at this process, my first thought was there must be a food grade spray, or close to food grade, that could seal the model after I touch it up.
Does anyone know if there is one available? Or are there settings that I need to address?
Thanks in advance for any comments.

There are several ways to ensure water tightness:
Thicker walls
I have experienced that 3 walls and 5 tops/bottoms with an outer shell of Concentric while the core is lines become watertight enough that leakage is almost none.
Lacquer
The oldest known method to seal a piece of porous material is a lacquer, followed by glaze. Glazes require to be burned at some thousand degrees, so are out, but lacquers are simple and easy. Basic clear acrylic lacquer can be used to seep into all the cracks and crannies and then harden out. It's easy to apply and cheap from home depot. Polyurethane lacquers also work. If you look to use it for food, ask if the lacquer is food rated in home depot.


Ultimaker Cura infill issues (weird vertical pillars due to underextrusion) I have spent ages debugging this problem but I can't figure out what I am doing wrong.

I have a Wanhao duplicator i3 (Prusa i3 clone) and until recently I used Wanhao's adapted version of the Cura slicer. But it's quite an old Cura version and I wanted to make use of the improved supports in the new Cura.

Unfortunately it seems like I just can't get the infill in the newest Cura to work. I copied all the settings from my Wanhao branded Cura version and printed the same file.

This is the result:

The infill is shaped like many tiny pillars. They are super fragile and while they do support material to be printed on top, they hardly withstand any pressure.

I have gone through quite a few testing cubes each with some setting altered, but nothing seemed to help.

It can't be the printers fault as I have successfully printed test cubes sliced with the old Cura in between (and not only once). Increasing temperature or slowing down the infill didn't help either. Neither did increasing flow rate or switching to triangular infill pattern. Also I have tried printing with all speeds set to 50mm/s and it still failed.

My standard settings (from which I have created many test cubes with each cube having some settings tweaked):

Layer Height: 0.12 mm

Init. Layer Height: 0.10 mm

Wall Line Count: 2

Top Layers: 6

Bottom Layers: 4

Infill Line distance: 5 mm (used to be 20 % in old Cura, but this is very dense in the new Cura)

Infill Pattern: Lines

Infill Overlap Percentage: 20 %

Printing Temperature: 200 °C

Build Plate Temperature: 60 °C

Retraction: Enabled, Distance: 2 mm, Speed: 60 mm/s

Speeds: Print:60 mm/s, Infill: 60 mm/s, Outer Wall: 30 mm/s, Inner Wall: 60 mm/s, Top/Bottom: 40 mm/s, Travel: 100 mm/s, Initial Layer: 20 mm/s

Combing Mode: All

This problem is most commonly caused by infill speeds which are too high.

Instead of printing lines, the filament is caught on one of the lines of the previous layer, leaves a blob there and only restarts extrusion when it hits the next line. Instead of extruding continuously the filament comes out in blobs at the locations where there's filament on the previous layer.

You can have good infill up to some layer and suddenly start getting this problem as of some layer. When the problem occurs the next layer is more likely to show the problem. It's snowballing.


How do filament properties change after printing? (In relation to water absorbtion) I have PLA and PETG filament.
I hear that 3D filament absorbs water and causes problems when printing but after printing they can be used with water and they are water proof.
So my question is why is it different after printing/what has changed to make it now waterproof?

Is PETG waterproof or does it absorb water?

Is there a limit on how much water PETG can absorb or will it keep going until it splits and turns to mush?

Filament that absorbs water prior to printing is subject to boiling temperatures as it passes through the heater block. In extreme cases, steam will be visible and a spitting sound will be heard. The filament will expand as the water exits, causing multiple structural and printing problems.
Once printed, dry filament may absorb water from the atmosphere, but is unlikely to be subject to boiling temperatures.
Waterproofing as a general consideration usually means the ability to keep water out, which is possible if the model is sealed and some printing conditions will adhere each layer well enough to the previous one to provide floating-type waterproofing.
PETG is hydroscopic, which means it will absorb moisture from the air. When printed properly (layer adhesion), the model can be waterproof.
These terms are independent and should not be used interchangeably.


Replicator 2x getting too hot with silent stepper drivers I equipped my Makerbot Replicator 2x with silent stepper drivers TMC2100. According to the product page I reduced Vref from 127 (factory default) to 25 in the printer settings as well as in my start G-code.

With this I get horrible layer shifting (a few millimeters!), even if I reduce print- and travel-acceleration to 300. The layer shifting is mostly happening on the Y-axis, but also on X-axis. Not only layer shifting was happening, also the extruder-motors lost many steps.

To fight this problem I increased the Vref little by little. At around 70 for X and Y axis (and 50 for extruders) all layer shift- and extrusion problems were gone. Also I had to install a dedicated fan for the stepper drivers, because they got very hot.

I was happy with this solution for about 10 minutes, then I noticed that the stepper motors are getting so hot I burned my fingertips by touching them. My guess for the motor temperature would be 80~90 °C.

So my question is: Are those TMC2100 stepper driver unsuitable for my usecase somehow or am I missing something? Is there a way to get the 3D printer silent while not overheating?

On behalf of advice in the comments, I mounted some heat sinks and measured the temperature via an IR-thermometer. With the old original stepper drivers I get 60 °C for the Y-axis and 66 °C for the X-axis. With TMC2100 it is 86 °C for both. (Each temperature measured at the heatsink)

Most Stepper drivers will have lots of energy passing through them so it is crucial to having a moderately sized heatsink to cool them off otherwise they will get too hot. Most stepper drivers found online come with heatsinks but you could search online for mini heatsinks.


Alunar m508 Firmware I have a Alunar M508 machine that I am trying to get new firmware on. The firmware that was loaded on the machine wasn't very good. The x axis was mirrored and the home point was way off. I was looking into Marlin to put on the machine, but don't have any experience on what to edit in the code to make it work for this machine.

Does anyone have any experience with this machine? Uploading new firmware that works or editing the code to make it work for this machine. I appreciate any help!

Here is a link to the firmware I am currently using. I'm on MacOS Sierra 10.12.5 using the 1.6.8 Arduino IDE.

The Alunar firmware you linked is a fork from the main Marlin firmware. If the bed Y direction is reversed, usually the stepper is incorrectly placed (mirrored) this is seen frequently for the Anet A8 printer which is very similar to your printer. In your case the X direction is wrong, this is usually related to the wiring of the stepper, reversing the connector by 180 degrees should do the trick (hardware solution). As a software solution, changing direction is not difficult in Marlin based firmware; you just want to invert the stepper direction; the following section in the configuration.h file does that for you:

// Invert the stepper direction. Change (or reverse the motor connector) if an axis goes the wrong way.
#define INVERT_X_DIR false
#define INVERT_Y_DIR false
#define INVERT_Z_DIR true

Just change INVERT_X_DIR to true.

If your home position is still not working for you, you should look into this section of the same configuration file:

// Travel limits (mm) after homing, corresponding to endstop positions.
#define X_MIN_POS -33
#define Y_MIN_POS -10
#define Z_MIN_POS 0
#define X_MAX_POS X_BED_SIZE
#define Y_MAX_POS Y_BED_SIZE
#define Z_MAX_POS 240

Change the MIN_POS positions as such that it starts at the corner of the bed. A more in depth bed center calibration tutorial can be found here.

P.S. Please do not print anti-wobble caps for the Z-axis rods (as mentioned in another answer), these are not reducing the wobble, in fact they cause problems. What happens if you constrain the top is that you get a statically indeterminate construction; forces and displacements are not predictable! Better solutions to eliminate Z-wobble are lifting devices that decouple X/Y movement from the threaded rod (eccentricity of the threaded rod) from the Z movement. Also fixate the threaded rod above the springy stepper-to-threaded-rod coupler.


Is E-axis steps/mm resolution limiting factor in print quality? I've been noticing in some of my linear advance test towers that the (very minor/fine) ripple pattern in walls varies with the K factor, which made me think that it isn't coming from any vibration in the print head motion, but rather from quantization of the extruder into discrete steps (i.e. wall gets slightly thicker right after a step, thins out afterwards until the next step, repeats).

By my math, with 1.75 mm filament and 93 steps per mm on my printer (Ender 3), each step is 0.02585 mm³ of material. At 0.4 mm line width and 0.2 mm layer height, there's 0.08 mm³ of material per linear mm, so that should give roughly 3 extruder steps per linear mm. That seems comparable to the ripple rate I see, although not exact; I suppose it varies somewhat because of linear advance and perhaps other reasons.

Anyway, to get to the question, am I missing something or is this the limiting factor in print resolution on my printer? It seems like isolated small details (smaller than 1/3 mm) won't be extrudable at all except as ooze, or over-extruded if they happen to cross a step threshold, and like things would be far worse if I tried to use a smaller nozzle and thinner layers. It seems that, ideally, you'd want the E-axis steps per mm to be sufficiently high that quantization is a non-issue (i.e. +-1 step is small relative error) for extrusions corresponding to a single X- or Y-axis microstep.

Your calculations about the theoretical extruder resolution are spot on. I did a similar calculation to evaluate which extruder to use with different hot ends, I paste the results. The dark cells are the input cells, the rest is calculated. You can see that for some lines I entered directly the mm/microstep value, since I wanted not a theoretical but practical result for my printer (3 mm filament) or for known extruders (BMG).

Concerning the question, the resolution of the extruder matters, but it's a bit complicated to estimate exactly how much.
In general, this are the factors I can think about.
A poor resolution may not impact straight lines much, since the rotation of the extruder is continuous and the extruder is unlikely to snap exactly to the desired microstep position as soon as you ask for it: it's likely a bit behind all the time, that's how torque is obtained (more or less).
The issue may become smaller with drivers which interpolate microsteps up to 256x.
However, whenever there is a change of flow rate, poor resolution implies that you cannot control the exact location/moment where/when the flow changes. This matters mostly at the end and at the beginning or retractions/re-retractions. Maybe you get more ooze?
However, the extruder resolution is not, in practice, as good as you calculated. In fact, as we know, microsteps reduce the incremental torque to very low values. The extruder is a motor which requires quite a lot of torque, since pushing the filament is quite hard, and it is unlikely that you can achieve all the time the 16x microstep accuracy you assumed. For example, due to friction in Bowden, hot end, ... the filament (= the motor shaft) may at a certain point stay "back" more than average. This would cause an increase of effective torque, pushing the filament a bit faster, which would it bring to in sync or so with the desired position, but at that point it would slow down, and so on. Depending on the average speed, this oscillation may be dampened (and then no rippling is visible) or may oscillate constantly, and you see ripples also along straight lines.
This is why I placed the usteps column in my calculations: it is meant to calculate a more realistic resolution assuming that no accurate microstepping is achieved. I assumed higher achievable microsteps the lower the load on the motor is (this means gears, or thinner filament).
Having a high resolution to begin with clearly helps to reduce this issue. You can try to increase the current to the max your drivers and motor and cooling allow, and see if the ripples change. I think it will be reduced.
You may also try to build the Orbiter extruder (linked also in the table) and see how it goes.


What is the strongest filament to use? I'm looking for a strong filament that can handle a large tension load and no bending deformation when a perpendicular force is applied to it. Any suggestions?

Carbon or glass fiber reinforced PLA likely has the strongest without deformation. PLA will snap before deforming.

Fiber reinforced ABS is also an option. ABS is stronger but will bend before breaking.

Both are hard on nozzles and may require a stainless steel nozzle.


Ender 2 LCD replacement My Ender 2 LCD is suddenly not lighting up.
Is it possible to replace it with an Ender 3 LCD?

Not easily.  Some folks have been messing with both 2 and 3 LCDs and based on their posts, the pinout is different between the two.
Ender 2 display pinout from when one GuzLightyear figured it out for Marlin (MKS MINI 12864 LCD):

          -----
     5V  | · · |  GND
   MOSI  | · · |  LCD_RS
 LCD_A0  | · · || BTN_EN2
  RESET  | · · |  BTN_EN1
BTN_ENC  | · · |  SCK
          -----

From a user called arnd13, the Ender 3 equivalent would be:

         -----
5V      | · · |  GND
MOSI    | · · |  LCD_A0
SCK     | · · || BTN_EN2
CS      | · · |  BTN_EN1
BTN_ENC | · · |  Buzzer
         -----

Maybe you have some luck in debugging your screen (sometimes with these LCD screens, a contrast adjustment resolves the issue).


Reason behind geometry of heater blocks? I understand the principle of why a heater block is used. Helping to reduce temperature variation as the filament is extruded using the heat capacity of the block.

But I’m wondering why it takes the form it does? I imagine it is cuboid in shape just for convenience as it’s easy to machine?

From a surface area to volume ratio a cuboid appears to be one of the worst shapes to use.

Note:
I am currently doing a project which requires me to increase the tool clearance of the nozzle of a 3D printer. Hence why I am exploring alternative print head configurations and heater block design trying to minimise the profile of the print head as much as possible.

A heater block has its shape designed simply by the necessity of the needs and the ease to manufacture them. Functionally, a heater block serves as:

a structural component holding the following components in a well-known position to one another:

heatbreak
nozzle
heater cartridge
thermosensor

a transmission medium of heat energy from the heater cartridge to the thermosensor and filament path.

this dictates the use of high thermal conductive metals

a thermal energy storage to equalize the heating pattern of the heater cartridge.

While this dictates the internal geometry of the block, it does not say anything about the external geometry. This is chosen entirely because of manufacturing, which strongly prefers square items in a vise with stop positions to allow repeatable machining.

While other heater designs are existant, for example wrapping a heater wire around the meltzone, the use of a machined structural element that houses bought components saves a lot of time in assembly Quality Control and subsequent repairs, as each component (heater, thermosensor, block) can be rejected or replaced on its own. This makes the machine all in all more serviceable.


What do I do when I have a little filament left? I just printed my first thing, now there's very little filament left in my Monoprice Select Mini v2.

What do I do about it? Yank it out? Try to print out what's left of it and hope it all extrudes safely?

I'm not sure what my next move here is. Is doing either, dangerous to the safety of my machine? I haven't seen any guides or information on this and I'm afraid I'm going to break something.

Heat the extruder up first, then remove the filament. You can remove the filament either by reversing the extruder using a command such as G1 E-100 F200, by using your printer's controls/LCD (if it has one) or simply pull the filament out by hand. To this end, most extruders have a lever that you can push to disengage the drive gear to make it easier to pull the filament out.

You can just heat the extruder up to printing temperature, but a perhaps better approach is a cold-pull, where you heat the extruder up just barely enough to be able to remove the filament (to, say, 120-180°C) and then pull the filament out. This has the advantage of removing more of the old filament and perhaps also taking some debris that may be stuck in the nozzle with it.

Trying to print it all out won't work because once the last bit of filament goes past the drive gear, you won't be able to extrude the rest of it. Feeding in a new bit of filament might push the old filament out, but it could just as easily get jammed.


QIDI x-one2 : Fan screws not holding filament feeder stepper motor in place I noticed a knocking noise one day on my QIDI and things seemed fine at first glance, then 7 hours later my print only had 3 layers. So I figured it was a jam, and I cleaned it out but every now and then I heard the knock again which cause incomplete prints. When I went back to remove the front facing cooling fan I noticed one of the screws that go through the fan to the stepper motor wasn't secure. This was causing the filament guide to rock out of place periodically until it got worse and worse.

I've been trying for hours but the screw just won't "catch" on the stepper motor that feeds the filament into the extruder. The screws aren't stripped because I can take the motor off and screw them directly into it with no problem. It's as if they aren't long enough anymore or that they're bent.

Has anyone else had this problem & found a solution that works consistently?

I just had this same problem and my solution was to push the motor as close as I could up to where the screw goes, because they weren’t lined up. I hope that helped.


How do you 3d print from an existing part when you have no CAD drawings? We have a toy with some broken parts, an Executivity Gear Master. I don't think it's made anymore. Some tiny parts were easy to break and we'd like to 3d print some replacement parts. We don't have CAD or any other 3D drawings file, just a few of the unbroken parts. What's the best way to get some of these printed? Do I have to turn this into a 3D file first? (Is there a quick way to do that from the part itself?) Or is there a way to do it where I just need the part, rather like getting a spare key cut from a pre-existing key being used as the template?

Here's a photo of the part I need to print. Placed next to a quarter for size comparison:

You can't print without a 3D model first. There are various ways you can go about this (or pay someone to do the same for you, ignoring any IP issues).

It is possible to generate a 3D model from a sequence of 2D photographs (there is even software which will allow you to do this freehand on a phone). Equipment exists which is specifically designed for this process, and you have likely heard of the services which allow you to get a 3D print of your own body.

You can take a 2D photo and import this into a 3D drawing package. Copy the features into a mesh, and extrude it. This might be a good approach for a complex shape, particularly if appearance is more important than precision.

For the shape you show here, the simplest approach for anyone with modeling experience is maybe to just draw it from scratch (with a few key dimensions). Your shape is only made up of a handful of primitive shapes.

Experiment in TinkerCad which is an online 3D editor to see if you can handle this yourself. It's not clear if you have your own printer, but this sort of part should cost less than $1 to print.

Strength might be a problem if they are already breaking...


Issues with OctoPi connecting to FlashForge Creator Pro via Serial Communication I've recently initialized OctoPi onto my Raspberry Pi, proceeded to connect it to my local internet, and then connected it to my FlashForge Creator Pro (2014 edition)
Everything seemed to be going smoothly until I tried to connect to the printer; the Pi didn't seem to be able to pick up a usable Baudrate (after being trying out all of the usable ones).
For example, when trying out 9600, I would get:

Trying baudrate: 9600
Send: N0 M110 N0*125
Recv: ��r>#    ���& �

What should I do to fix the problem?

Note that I got the same types of messages back (with garbled 'special' characters) when trying using the "auto connect" feature.

I got the same problem.
Auto-detect baud rate was not working too.
So I manually tried every baud-rate and finally found one working, for me it was 115200.
Good luck!


How to correct XY mirroring? So I made a 3D printer from scratch. It is a RepStrap based on a Prusa i3 running Marlin 2.0.x.
It prints fine and accurate, but, The trouble is that the XY plane is mirrored and I don't know how to solve this.
I'm using Marlin 2.0.x on an SKR 1.4 controller board.
Any pointers would be greatly appreciated.
Thanks!

First of all, make sure that you have correctly identified the X and Y axes, and that the stepper motors (and end-stop switches) are connected to the correct ports. The hot end moves on the X-axis, and the bed moves on the Y-axis. If you connect the X and Y motors the wrong way round, you will get reversed text.
If the X and Y motors are connected to the correct ports, you may need to invert the motor directions in firmware. There are #define statements to allow you to do this.


How do you assure that you print layers that bond correctly? I'm fairly new to 3D printing but I'm getting the steam up and I chug out pieces without much hassle. One thing though is that I have the impression that sometimes, parts are easily broken, and I suspect bad adhesion between layers.

I'm printing eSun PLA at 208 °C (212 °C first layer), bed at 50 °C first layer then 30 °C.

When I print the Benchy boat, it feels extremely sturdy (even the small chimney is unbreakable by hand), but if I make, say, a 50 mm diameter cylinder with 4 mm wall thickness, It breaks fairly easy along some layer. I don't see any specific error, it "looks" okay.

So my question is:

How do you assure that you print layers that bond enough?

[Edit] I already know that might actually cause bad bonding (low heat, underextrusion, ...) but I'm looking for a way to see when it happens.

Here is an image from when I stopped mid print (you can see the little ooze string just at the start at the crack) for checking dimensions. The next layer didn't bond well because, I guess, the already printed part had cooled down when I un-paused the print (say 1 minute later) or maybe the z-axis went off a bit when I touched the build plate.

Is the only way of knowing layers bonded correctly, to try to break the part apart?

I think the reason why the large cylinder is breaking much easier than the smokestack would is because of leverage. If you print the same cylinder at a much smaller scale it might be more difficult to break it. Think of taking a wooden stick, if you try to snap it by holding both hands near the center, it would be difficult but if you push on the very ends, the leverage will make it easier to snap. I have the tug boat on my desk right now and I was unable to snap it, instead I broke the cabin section just right above the steering wheel.

Now to answer your question. One of the faults in larger prints having weak layer adhesion could be a number of things. I think a common fault is under extrusion. If the nozzle has a high enough gap from the previous layer and it extrudes just enough filament to touch the layer but not necessarily push it snug, it could be a weak bond. This is like tape, usually when you want to make sure it will stay stuck, you press hard and rub it in. So I imagine filament shouldn't loosely flow onto layers but instead be pressed hard against the previous layers. Visually this is hard to judge but I noticed getting my first layer very close to the print bed makes every other layer stick very stronger on the previous one. You get a small skirt on the first layer but it does tend to give me a stronger bond between layers. You can easily slice off the skirt with a blade. Increasing the extrusion multiplier could give the same affect without needing to adjust bed height/leveling, but this can end up giving you some nasty walls.

Another thing I recommend is to check your Z-axis. This is difficult to measure and best to find out by print quality on tall structures. On my first printer I had the issue where my threaded Z-rods would bind and cause one of the two rods to get a slight bit ahead. This caused a layer split focused on the side opposite of the faulty rod. This made many prints very prone to breaking at that point. I had to rebuild my Z-axis assembly to correct this.

Print temperature can help, try raising it up by 5 to see if this improves the bonding.

Lastly, try another filament. Filament tends to go bad due to moisture exposure, that is why usually you receive it airtight with a small bag of silica to absorb moisture. If I use filament which has been sitting out for months, just squeezing my part separates the layers in almost a slinky kind of way.


Creating positives for a food-safe silicone mold: safe? First, a little background. A couple of years ago, I was researching making my own candy, and I came across this page: Lego brick shaped gummy candies, describing how to use real Lego bricks as a positive to make silicone molds for Lego brick shaped candy. Now that I have a 3D printer, and inspired by the usual description of ABS filament ("It's the same plastic used to make Lego bricks") it occurs to me that I can now make any positive I want.

The question is, would that be safe? I know the filament I'm using is not food safe, but if I create positives for a food safe silicone mold, would toxins leech into the mold? And if so, is there a barrier I can use to prevent this, such as some kind of coating?

In principle, ABS is safe for contact with (cold or room-temperature) food. The two main concerns specific to 3D printing are, assuming you start with a filament that is not itself contaminated:

Pores and holes in the printed part which may harbor bacteria
Impurities introduced into the plastic during the printing process

I doubt that the silicone mold will capture the pores and holes with sufficient detail to be of any concern (it certainly won't capture the internal structure, only the surface).

That leaves us with 2. It has been noted that brass nozzles contain trace amounts of lead. This lead can contaminate the printed part, which may in turn contaminate your mold, which may in turn contaminate your food. I don't think this is of realistic concern, since we're looking at trace amounts of trace amounts of lead. The nozzle might also have burnt plastic stuck to it (which might be carcinogenic) so you should make sure to do the print with a very clean nozzle and at a temperature that is not too high.

ABS is food safe for contact with cold or room-temperature food. It is however not food safe for contact with hot food, because at higher temperatures the food may leach certain chemicals out of the plastic. Your application is one of low temperature, but silicone is not food and might perhaps leach some contaminants out of the plastic, regardless of temperature. However, this concern is not specific to 3D printing, as it applies to the method of making moulds out of Lego bricks as well. Therefore, making moulds from 3D printed positives does not appear to be different in a food safety perspective from making them out of LEGO blocks.


OctoPrint mjpg-streamer configuration I'm running an OctoPi Raspberry Pi installation of OctoPrint, and the webcam images are too bright.

I found some documentation on changing the exposure of mjpg-streamer, see github:foosel/OctoPrint/MJPG Streamer configuration, but I don't understand where, or how, to change these settings.

The commands in your documentation only work with the Raspi camera.  If that's the camera you're using, you can use the tools mentioned from terminal on your Raspberry Pi, or over SSH.

If you don't have SSH setup and are using your Raspberry Pi with a keyboard and mouse, you can access the command line by pressing ctrl+alt+f1  remembering that ctrl+alt+f7 brings back your GUI.

Setting exposure for Raspi camera

First navigate to the folder you installed mjpg-streamer.  If you installed it in your home folder:

cd ~/mjpg-streamer/mjpg-streamer-experimental

Then use the input_raspicam.so utility to set the exposure using whatever preset you'd like.

./input_raspicam.so -ex night

If you don't have a Raspi camera

I'm currently using a Logitech HD Webcam C310 with OctoPrint.  I'm pretty sure setting the exposure for that is a pretty standard operation and you shouldn't need to install anything.  v4l2 (video 4 linux 2) comes installed with Raspian.

To set the exposure for a Logitech camera (possibly others too) first enable manual exposure mode (1 for manual, 0 for auto)

v4l2-ctl -c exposure_auto=1

Then set the exposure value with

v4l2-ctl -c exposure_absolute=100

replacing 100 with whatever value you'd like.  The values start at 1 and have a maximum value of 10,000.

These commands can of course be run over SSH.

You can also run

v4l2-ctl --list-ctrls-menus

to see all the options for your camera.

Here's a screenshot of my ssh session and my OctoPrint interface for context:


Multipart 3mf file, need to extract one of those parts for printing. I have a 3mf file that has 24 parts in it.  I want to extract one of those parts for printing.  I have Solid Works, Magics, and NetFabb.

If your 3D file has separate objects and vertices and are just merged together then do the following:

Import into Magics;
Select part (in the part list menu).
Right click (in the part list menu) and select Shell to parts;
(Be very careful here) Select the area you want to isolate with the translate tool. If you don't know how to do this just left click hold and drag the mouse to select an area inside a box;
Use translate tool to move it a little ahead from the original grouped object (just drag on any axis);
Right click (in the part list menu) and select merge part.

Should work out fine. Tell me if you get stuck.

This can also be done on Netfabb. Not on SolidWorks.


BLTouch not touching bed while leveling I have an Ender 3 Pro that I installed a BLTouch sensor on. After I auto-home, I level bed and it deploys the probe in the right spot, but doesn't go down far enough, then goes back up and stops leveling.
I am using the wiring for BLTouch for Z homing on SKR mini E3 v1.2. I am using Marlin Bugfix-2.0 with BLTouch and a few other things enabled.

Configuration Files
Video of Problem

I think I fixed everything. What I did is I used this guide <youtu.be/y_1Kg45APko> which was a guide by makes'n'breaks on setting the probe z-offset using pronterface and then reverted to the original firmware that was on this page<github.com/bigtreetech/BIGTREETECH-SKR-mini-E3/tree/master/…> Which was the marlin firmware for bltouch for z homing for my mainboard.


In FreeCAD, how do you copy a sketch from one plane to another? I'm using FreeCAD, and I would like to duplicate a 2D sketch on another plane, but I can't seem to find an obvious way to do this.

I’m assuming you are working in the Part Design workbench. Select the sketch and click Edit->duplicate selected object. Make sure that only the sketch is copied (depending on the version, either deselect the plane or click don’t include dependent objects). This will produce a duplicate sketch in the active body (if you want the duplicate in a different body, make sure it’s active first by double-clicking it if necessary). You can then click Part Design->reorient sketch to move it to a different plane.
By the way, FreeCAD has a very active and helpful forum at https://freecadweb.org. I highly recommend asking FreeCAD questions there.


New use for extruder port Is there a way to change the use of an extruder port on a 3D printer motherboard to move stepper motors (on y axis) on a 3D printer?

This is for a school project, and we have replaced the extruder with a laser for cutting material.

We were tasked with converting a 3D printer into LOM 3D printer, the laser is set using the fan port, however we still need two stepper motors to move material from one side of the printer to the other after each layer of material is cut.

The mother board we are using is WitBot MKS Gen L V1.0 Controller Board Integrated mainboard Compatible Ramps1.4/Mega2560 R3 with A4988 Motor Driver for 3D.

If you are planning to use the printer via GCode entirely, then I don't believe it would be too complicated. For example, Marlin treats the extruder as another axis and uses absolute values for it (if absolute mode is on, of course). Since you want to have two steppers, you would have to connect them in either series or parallel (usually the Z motors are wired in parallel on RAMPS type boards, but many people are going for series since it has some benefits, one of them being that the torque will be much more similar between the two motors). Of course lower the stepper driver current to the minimum before connecting, then adjust it to whatever value you need.
I don't think it will work too well if it has to keep the roll tight - in that case, you could be better off by using only one stepper and some kind of force to hold it tight... maybe a small DC motor at low currents?

You can modify your printer firmware and set your own pin assignments for everything, for example in Marlin you have the pins.h file where every pin from the Mega is mapped to different headers and drivers. I don't know if there is any LOM slicer or firmware available, but you could just use GRBL.


Which nozzle should I buy for Anycubic i3 Mega? I'd like to buy a new nozzle for my Anycubic i3 Mega because it's not precise enough - it fails to print small details like 1 mm eyebrows.

Currently it has a 0.4 mm nozzle and I'd like to buy a better one but I don't know how to choose one which is compatible with this printer.

If you have any advice, please let me know.

According to Anycubic this printer uses the E3D V5 type hotend as can be seen from the linked video of the AnyCubic Mega:

The brass nozzle you see is fully compatible with the E3D v6 nozzle and can be found on those typical auction and Chinese websites by looking for "E3D nozzle". They are also available from E3D directly, the designer/creator of the E3D hotend family, and other specialized manufacturers like the Olsson Ruby. These nozzles have a short nozzle (snout) and are screwed into the heater block with M6 threads.1)

The smaller the diameter, the smaller the filament traces and the higher the print detail resolution. Note that a smaller diameter causes thinner walls for the same amount of (vertical) walls and may require additional perimeters to get similar strength and rigidity. The maximum layer thickness also decreases, as prints with a layer height above 75 % of the nozzle diameter have very poor quality. As an example, a 0.25 mm nozzle should not print layers thicker than $0.75 \times 0.25\text{ mm} = 0.19\text{ mm}$.

As such printing with smaller nozzle diameters increases print time. Also note that a smaller diameter requires more force to push the filament through and could use some extra temperature to make the filament more fluid or reduction of the print speed.

Just buy some spare nozzles of different nozzle diameter and experiment what works best for you.

1) - The other popular style of M6 threaded nozzles has a long body and long taper (often referred to as MK8 nozzle; they come in two different shapes). While these might work, they extend from the heater block considerably further and might need readjustment of the heater block (as explained here):


What criteria do I need to be aware of when buying a 3D printer for personal use? I'm interested in designing & 3D printing as a hobby (e.g. printing chess sets, small toys for family etc.)

Conducting a Google search has brought up a range of small, cheap printers, but beyond that I don't know how to differentiate them.

E.g. selling points include:

"liquid light-sensitive resin"
"partially assembled" with "very few parts and minor configuration"
"Wi-Fi enabled"

My question is, which features are going to benefit a small-scale, new enthusiast to 3D printing?

PS. The software I intend to use is Windows 10 3D design

PPS. I'm not a graphic designer by any means, just a new enthusiast.

Here are few things to consider from my point of view

Printing technology

The first thing that you need to take into account is printing technology. The most common[citation needed] right now is Fused Filament Fabrication. "Liquid light-sensitive resin" is being used in Stereolitography and Digital Light Processing - the SLA printers I found are less common and more expensive than FFF ones.

Price

Need to decide on budget. You can buy printer for 60k USD and 400 USD. Quality is somehow linked to price but that's not a rule. You can buy a shitty printer for a lot of money.

Printing area

Bigger allows you to print bigger things. You need to ask yourself how big things you really want to print. Remember that 3d printing is quite slow process - how often you will want to print big things that will take 60hrs+ to finish?

Printing materials

What kind of materials you want to print with? Some materials will need higher temperatures so check the max hot-end temperature, some will require heated bed.

Assembled or DIY kit

You can usually get kits for self-assembly cheaper than Ready-To-Print machines. However, it will require additional skills (i.e. soldering), tools and time to assemble. I am not sure if I would buy DIY kit for commercial use, but as an enthusiast I immensely enjoyed putting my Rostock Max together.

Reviews and reputation

It is generally safe to buy printer that already has some users. Beware of new magical Kickstarter printers which will "change the 3d printing forever".
Reddit /r/3dprinting suggests that your new printer should meet 3 criteria:

Printer passes the youtube test - has lots of youtube evidence that this particular printer is working.
Printer is out of the pre-order phase. This means that all pre-orders have been delivered.
Printer has a reputation of working well among current users.

I found it to be a very good set of rules.

Upgrade capabilities

That's very user-dependent, but this point is very important to me. I want to be able to change and improve certain parts of my printer. Check if you can switch the extruder, replace the hot-end etc.

Support

I think one of the most important points. See if you can find a forum for your printer and how active community is. It will be immensely helpful if something goes wrong (and it will).
Also, company support is very important. What will happen if you need a replacement part or your printer will stop working altogether?

This list is definitely not complete.
There are many more things that might be taken into account like configuration (delta or XY), multiple extruders, closed cases etc.


SLA resin post-processing: gluing parts together I've recently purchased an Elegoo Mars Pro 3d printer, and I was wondering when printing large pieces that need to be printed in different steps: is there some kind of post-processing to make it more suitable for gluing them?
I know of joints and so on, but sometimes pieces are big but not thick enough to be able to put a joint somewhere, so I guess the only solution would be to glue them.
Should I use some kind of specific glue to get better results with resins? Is there any process (post-processing, reducing layer height when printing, leave the resin being curated more time...) to improve the sticking of the different parts? Or can we go with any kind of "strong multisurface glue" without any further post-processing steps, and the results should be the same in matters of quality?
Thank you!

You can definitely use glue - however you can also brush some of the liquid resin along the edges of the two pieces, push them together and cure them, this will fuse them together.
You don't need much, and you need to watch for drip out while curing (don't your fingers in it)


Printer is Confused-Printing in Air Literally So I got my 3D printer (Anet A8) a few years ago and put it together. I couldn't figure out how to use it. Then about a month ago I decided to try again now that I am older and got it to work. I know more than I did by far. I have printed about 15-20 different times now, but then this problem occurred just now that I have never seen before. I tried looking up what it could be and google results in nothing and this exchange leads to one thread that is close to what I am having difficulty with but doesn't really help. I got the stl file from the internet on thingverse, so I am fairly certain  they must have clicked the center and arrange when in the cad software to make the item, which is a phone stand. So my print all of a sudden starting printing in air. Here is a picture and thanks for the help.

Here's the pattern.

The problem is, you didn't slice the g-code using support. It won't print right without it.


Raw material for 3D printed injection mold If I have to make an injection mold (for resin based raw material) using 3D printing, what raw material should I choose – PLA,  ABS, HIPS etc.

P20 mold steel is one standard. Hardened parts are required for long life, depending on the service and material (some materials are quite abrasive).

You can get a small number of relatively poor quality shots out of epoxy if it is properly supported by a metal box. Your best bet if you want to include 3D printing in the equation is probably to use epoxy or lost plastic casting from a 3D-printed master. Aside from the requirements of core and cavity with sufficient strength, there are requirements for vents, cooling tubes (bubblers and such like) ejector pins and slides that complicate most real molds. Productivity demands a high heat transfer rate, for very small quantities of expensive parts, thermal design may be less important.

Temperatures and pressures are very high in injection injection molding- high enough to melt the materials you mention, and the pressures are in the 10K PSI range, so a 4" x 4" projected cavity will have a pressure in the 80 ton region.

If you have sintered and filled metal 3D parts they may be suitable, but from the prices I've seen you'd be better off to use conventional machining. Finish is also very important if you want the part to come out of the mold, with hours of semi-manual polishing not uncommon. If you don't have fine surface finish you will need extreme draft angles.

The requirements can be considerably relaxed if you are molding soft parts such as the PVC or TPE overmolds on cables. The pressure is less and the finish less important because the plastic is soft, but the temperatures are still quite high. This is sort of a sub-category of injection molding and specialized machines are used.


Fill hollow part of body in the 3D model Sorry, I'm new in 3D printing and modeling and I need help.
I bought a 3D model with a hollow part of the body that doesn't print on my printer normally (with very high resolution (layer is 0.12 mm, the nozzle is 0.4 mm) because the walls are very thin).  I tried to make it as a solid in MeshMixer or ZBrush, but  I can't.  Can you help me, how I can fix this defect?
I use Cura for slicing.
I know, that I can take a thinner nozzle (0.2 mm) and Cura will slice it better, but I want to make this model solid so I could print it with nozzle 0.4 mm.

This is a problem with the model, you need to make sure that the model isn't hollow. You might be able to get around this though if you use scaffolding, it might recognize the overhand hand build supports for your print inside of your print, you just might have to mess around with the scaffolding settings a bit.


My first 3D printing - I need some advice or tips It is my first time for 3D printing, I read some tips for forms, minimal thickness, angles, round or flat, but I am still not sure if I am going to do all well for the first time.

For my college final project, I had to make a small prototype and it requires an enclosure.

My concerns are:

I am not sure if my design will require supports
Overhangs
Printing Orientation

Here part of my design:

Most walls are 2 mm+ thick
The lid is a separate file, but it is really simple just a flat rectangle, I believe it is going well the first time

I see this:

  I had to make a small prototype and it requires an enclosure

and this:

  yes, it is hollow inside

How do you intend to get your item inside the result? This part really needs to be two pieces with two separate prints. Basically, a box and the lid, where you leave space for screws, include tabs, or plan for glue connections.

Finish that alteration, and the support issue suddenly becomes much easier. Most slicers have options to generate support for you, including limiting support to spaces between the model and build plate. Now you can rotate the angle at the which the part is printed in order to minimize your support needs, or so that most of the connection points for the support will not be visible in the finished product.


E3D V6 nozzle seized into heater block The 0.4 mm brass nozzle in my Prusa i3 MK3 is worn out - the extrusion hole is visibly larger than the replacement nozzles I have to fit. So I’m trying to replace the nozzle.

Unfortunately the nozzle seems to be stuck in the heater block. So far I’ve tried:

Heating the hotend up to 285 °C, rotating the heater block slightly and trying to unscrew the nozzle with a wrench. (I exactly followed the Prusa YouTube video on changing nozzles).
Leaving the hotend at 285 °C for 15 minutes and trying again - I found some other reports online this had helped. However it made no difference in my case.

In an effort to try and remove the nozzle from the heaterblock, I’ve now accidentally bent the heatbreak, so I’m going to have to replace some or all of hotend. But I need to get the nozzle out, so I know which parts to order - if the nozzle breaks off in the heater block I’m definitely going to need a new heater block as well.

What else can I try to free a seized nozzle?

This is the original factory-fitted brass nozzle, and the hot-end was pre-assembled in the kit I received.

Try to,
First, remove the heat block from the extruder/heat sink. Heat the hot end to ~ 230 'C. Then try to unscrew the nozzle while holding the heat block with a wrench or plier. Be extra careful with the heat block and with the plier.


Inconsistent Layer Issues I was having some issues with printing, most noticeably in this picture:

The layers are very noticeable and sometimes have gaps, and the overhangs don't print very well (although the former is more of an issue). I just calibrated my E-steps so I don't think that is the issue. It was doing the same thing before I upgraded anything (i.e., I had issues on stock hardware).

My printer is an Ender 3 with the metal extruder upgrade (which replaces the plastic parts as seen here), an E3D v6, printed fan duct (Bullseye), glass bed, BLTouch, and vanilla Marlin. Pictures of it are also in the below album. The printed upgrades were printed on a Prusa MK3S and don't have the same issue.

I am using Hatchbox 1.75 mm gray PLA, printed at 215 °C with my bed at 60 °C. I am using Ultimaker Cura 4.1 but was also having the problems on an older version of Ultimaker Cura (maybe 3.6, but I can't remember which it was). The problems also existed with some Hatchbox 1.75 mm black PLA but I used the same roll on my Prusa MK3S without any issues, so I'm not sure if filament could be the cause (although it is a different printer so it's still a possibility).

I have tried at different printing speeds and the problem still persists.

I also recently tried varying the temperature during printing (first up to 222 °C then down to 200 °C) with no noticeable difference.

Extra pictures here.

Model is part of Printable Scenery's sorcerer tower.

These lines could be caused by a mechanical issue with the printer; it looks as if the positioning is not up to par.

This can be related to loose belts of the X-axis and Y-axis, or play in your system, e.g. look at the rollers of the carriage.

I've experienced an issue with play between the idler mounts and the smooth linear rods on a cheap 3D printer kit myself, but that is not the case here. Just added to explain where play may come from.


What is the best way to connect 3D printed parts? I want to print a model of an animal cell.

What I have so far: I managed to use different colors to print out the different parts of the cell.
My question is: what is the best way to connect plastic 3d printed parts?
Glue? Melted plastic? I need it to have a strong connection and not very visible when used well, and preferable dries fast.

For ABS print, I recommend acetone. It is not a glue, but it will dissolve the plastic a bit and if you apply it to both connecting parts and push them together, they will stay connected after the acetone dries. However, it does not dry very fast and you have to be careful not to destroy the object.

For PLA I usually use regular super glue (Cyanoacrylate).


Is 3D printing useful for making everyday objects or is it more for special hobbies? Have people been using 3D printing to genuinely create a number of needed objects in their homes, and if so, what? Or is 3D printing better for special niche interests like art projects, home engineering projects, etc?

Have people been using 3D printing to genuinely create a number of needed objects in their homes, and if so, what?

Yes, but in a very limited sense. If there is widespread demand for an item, then it will always be available from stores. This is basics economics: if there is enough demand for something, somebody will step in and provide the supply. The store-bought alternative will almost always be of better quality and relatively cheap.

3D printing can be useful to create a niche part that is needed but not readily available, such as replacement parts for appliances long out of production. This unfortunately takes a lot of time since you need to make a 3D model of the part yourself, which also requires considerable skill.

Some examples of items that I made for my home:

Custom brackets to hang blinds when the store-provided ones did not fit my window.
A special mounting bracket to more easily hang a ceiling light panel.
Replacement wheel for a vacuum cleaner.
Cover plate for a deprecated telecom socket.
Fix for a broken clothes drying rack.

3D printing can also be used to create "trinkets" such as custom vases or similar objects.

I would say 3D printing is a bit like woodworking as a hobby: it is a skill that can be used to make genuinely useful items, but going to IKEA is a perfectly viable alternative.

  Or is 3D printing better for special niche interests like art projects, home engineering projects, etc?

It is ideal for this. I do not know of anybody who has a 3D printer specifically for home use. However, there are many hobbyists that use 3D printing for another primary purpose that occasionally find their 3D printers useful around the house.


TEVO Tarantula Z-Axis Lowering Too Far After Endstop Triggered A z-axis homing issue is giving me an ulcer. I'm hoping someone can help with this.

As per usual, after the Z endstop is triggered on my TEVO Tarantula the gantry raises a bit then slowly lowers back down to the z=0 point established by the trigger. However, the gantry is now lowering well past the point triggered by the endstop. It's forcing the hotend to press down into the bed, and I need to reset the printer to avoid any damage.

I'm at a loss to understand why, and it's making re-leveling the bed impossible. Once I have the bed leveled, an auto home grinds the hotend into the bed.

I've done some cable management in the past couple of days but everything is connected where it should be. The endstops are responding, I've even manually triggered them so I know they're working, but the Z refuses to stop where it should.

I've printed at least once since organizing my cables but the bed wasn't level and then I noticed this issue when homing the Z for re-leveling.

For context, I've had several projects print successfully recently so things had been working fairly well. I haven't made any changes to the Marlin software since originally setting it up months ago. I had been poking around in some settings on the unit but I'm quite sure I reverted everything I tweaked. Regardless, I can't seem to find the menu I had accessed before, and I don't think I've ever had the TEVO successfully save any customizations made via the LCD interface anyway.

The soldering in the Tevo components is very low quality as I replaced/resoldered most of the end-stops.

As the gantry goes down - please ensure that the cable is not pulled over (no contact) and there is contact on the edge of the acrylic and the end-stop, also the small acrylic switch holder could bend/slip a bit. Finally, the sensor connection to the main board could be dragged by wires that are connected to the hot-end.

To validate micro-switch behavior - lift the Z-axis (about 100mm), then set home position and manually trigger the end-stop switch. That shall lift the Z-axis, so then trigger again to see if that works. You will still have a plenty of time to stop the printer if the switch does not work.

If that works, then the reason could be in slipping edge of the black acrylic plate and the micro-switch. Also validate the mechanical connection (if there is a loosening screw (the small on the switch plate)).


Make holes in PLA print I have  a print I need to make holes in.
I have read some other threads where the answers was in short, "don't, print the holes", and "make sure to make the hole from the top or bottom".
The problem is I need the hole in the side of a print with about 1 mm walls.

The holes I need is to run a USB cable in and a few to hold 3 mm LEDs.
One of the holes needs to be 10 mm.

What is my best option?
I read that there is a risk it cracks, so I was thinking maybe I can use a soldering iron for the smaller holes?
That will melt the plastic and create nice smooth walls, right? Less risk of cracks?
The piece will not be loaded in any way, it's just holdin it's own weight.

I never anticipated that it would be an issue to drill holes in prints. If I had known it I might have tried more to change the print before ordering it.
(I don't have a printer to make a new one with.)

Note: The part has already been printed. This is a question about post-printing processing, not modelling for a new print.

You're going to have to drill those holes. The plastic will melt if you drill too quickly. If at all possible, use a slow speed drill, a hand drill, or wrap a cloth around a drill bit and twist it with your hand. If you go too fast, the part will melt. If you press to hard the part will break.

Once the hole has been drilled you will need to reinforce it with a metal/plastic tube of the required diameter. Press the tube into the hole. I don't know what your wall thickness is, but try to ensure the tube is the same length.

If at all possible you should get flanged tubes like these from mc master car:

The parts with the 1/2 inch inner diameter and 5/8 outer diameter should fit your 10 mm requirement. The rest is up to you. Go to mcmaster.com/inserts scroll down to "Other Inserts" then "Tube and tube fittings".


G-Code for resetting to 100% speed I had problems printing parts and I figured out that my children have turned the knob of my Prusa i3 MK3 and set the printing speed to 112%.

Since I'm not experimenting much yet, I'm not printing at different speeds than the original speed. I wonder whether there's a G-Code command that I could let Slic3r insert at the beginning of each print to ensure the print starts with 100% speed.

You can put the speed to 100 % by G-code command: M220 S100.

The M220command is described here.

Know that speed changes sent to the printer have an effect on the next printed layer, it first finishes the current layer at the speed commanded before starting printing the layer.


MakerBot Camera Stream Is it possible to use the onboard camera on the 5th+ generation MakerBot printers to stream or save to a file?

I'd like to try and use the stream for customers on my 3DHubs account and they recommend setting up a YouTube stream. However, even if I'm able to stream to VLC Player or something, I'd like to get the video/images somehow.

I own the gen 5, not the gen 5+. As far as I can tell, the camera has not gotten much of an upgrade and the software is also just as limited. That said to be sure I verified on several sites such as this reddit.

There are some that claim that the software is open source. I do not think this is true given the parent company. Following even if it was you do not want to use their camera. It is shocking how cheap they went on this ultra premium printer. Which despite printing very well has not been received well. The main issue is that the camera is 320 by 240! That alone is enough to derail your quest I am afraid.

Take a look at this raspberry pi project on building your own camera set up. Though really any wireless camera setup should do. Using a Pi has the stand alone advantage.


Help diagnose Z-banding The printer is "Monoprice MP Select Mini 3D Printer V2".

This is how my printed fan part looks like:

These printers are notorious for their Z lead screw assembly (M4 bolt & nut) so I installed flex coupler and aligned the M4 bolt and motor shaft so that the wobble is minimal. It is still there, but I don't think this amount of wobble would produce something like what I experience. Please check out the timelapse video at the end.

I also tightened up Z guide rails (no rattle, very little slop)

Moreover the banding appears to be less pronounced and have alot greater period for vase prints

(this is extruded ellipse printed along Y axis).
I tried:

slowing down print by 50 % - no effect on banding.
monitored hotend temperature with external probe on the heater block (-+5 °C)

The banding appears to be almost exclusively in Y axis direction; for example, the same ellipse printed along X axis:

Now, same ellipse in layered mode (seam side) printed along Y axis

This differs from the traditional banding as observed from Z wobble induced banding as e.g. explained in this answer.

Your banding patterns clearly seem to form diagonal bands, this is most probably a combination of the lead and the full rotation of the stepper. The most logical explanation is that the layer shifts as a whole in X-Y direction (when seen against the print height, this movement is concentric seen from the top). This means that the next layer is positioned over the previous layer in a concentric pattern. This hints to some sort of defect in your X/Y-plane assembly and should be investigated further.

This is difficult to visualize, but this sketch shows the issue for some layers:

This could be related to the belts of the X and Y-axis, play on the drive pulleys, non-straight lead screw, guide rods with play, play in general, Z-stepper alignment to the threaded rod, etc. Considering the amount of Z-wobble fixes shared by the unofficial MP Select Wiki, the best place to look for is the Z-stepper to lead screw coupling.


Maintaining fine details while applying smoothing methods I've been reading and experimenting with Acetone vapour smoothing on some printed ABS parts. My problem is that I need to selectively smoothen the printed parts which vapor smoothing doesn't allow. In particular, the cogs, whose sides I was trying to make smooth ended, up with smooth rounded tips, which was a disappointment.

An example of what I was trying to smoothen is would be something like this:

So how can I maintain fine details (like the cog tips in the image above) while applying smoothing methods to printed parts?

A technique I've used in the past is to make a acetone slurry of the same filament used to print your object, and carefully paint the details you need to smooth.  You must be careful and only do a very thin coat or you may damage your print. You can add extra coat if needed to make sure the acetone has evaporatored from the previous coat of ABS filaments slurry.


How to switch E0 to E1 for extruder? I have a K280 3D printer with a MKS V1.5 and Repetier firmware.

I’ve damaged the transistor associated with E0 (3rd one on the right) and so that means I need to avoid that. I’ve decided to switch to E1 for the extruder but I have a feeling I need to go in the firmware or Repetier host and manipulate that.

I don’t know how and any help would be great.

The only info I can access for the firmware is the EEPROM and it seems that I can’t edit the pins. Also, do I need to edit the pin for the sensor or just where the extruder goes?

If you go through the Repetier-Firmware configuration tool for version 1.0.2 you can select the E1 stepper for the E0 extruder (or whatever stepper you want to use for it) in the tools tab sheet. I'm not familiar with Repetier, but if that does not work you would have to switch pin numbers.

If you already have a Configuration.h, you can use that one (by loading it into the configuration tool) and alter the E1 afterwards so that you do not have to enter all the other options by yourself.

Edit: After some investigation, you can find your configuration file here as described here, so the only thing you would have to do is to load the file in the online tool and adjust the E1 stepper for E0 extruder.


How to slice a model to ensure at least a certain amount of filament per layer? I am designing a part with a material which can bear up to a certain stress.

To keep the stress within the design limits, I need to ensure a certain surface of solid material per layer, in other words a minimum amount of extruded filament per layer and a smoothly changing infill ratio so that the infill can transmit the load efficiently to the neighbouring layers.

The part has an irregular shape and I cannot simply increase the infill ratio for the whole object because the part is big and it would cost more time and filament. I also cannot build straight pillars of solid material inside the part because there are no regions which are suitable for a continuous pillar.

How can I calculate and apply a smoothly changing infill ratio or in general how to ensure that each layer is made of at least a certain amount of material?

I use Prusa Slicer for slicing and Fusion 360 for the design.

Related questions about variable infill, which however don't answer my question because I need to specify the amount of material and because I need a smoothly changing infill ratio:

Different infill in the same part

slic3r: Can I vary the infill percentage for different heights of my model?

I think you have a major XY problem. The amount of material per layer is not what determines the part strength. Unless additional material is placed in a manner that reinforces against the stress you're designing for, it's just wasted. Moreover, infill in particular is not terribly useful this way, as infill has to rest upon the support of existing infill below it. If you suddenly increase infill density at a particular layer, it will not provide any significant additional strength because the added lines will be unsupported and will not bond strongly to anything. Even the next layer above them, and the next after that for quite a few layers, will not bond well because the unsupported lines can just bend downward when the nozzle goes over them, rather than providing a surface for the newly deposited material to press firmly against and bond to.

Generally, infill is not your main source of part strength anyway. I would start out (especially if you can test; if this is a one-off thing, the material cost is not going to be an issue anyway and just go with overkill) by increasing the number of wall lines (wall thickness). Walls generally provide the most strength, and the amount of material used will be proportional to cross-sectional perimeter rather than area, which typically will vary "linearly" rather than "quadratically" (I use these terms loosely since I don't know right off how to make it rigorous - what the independent variable should be thought of as being). My usual default (and I believe Cura's) is 2 walls; I would expect 4-5 to be very strong, and as long as you keep at least 15-20% infill, probably stronger than what you'd get by any increase in infill percent.


Gnarly filament: just one of those things, or grounds for complaint? everyone.

I'm a relative newcomer to 3D printing, so I don't know what constitutes an unacceptably bad spool of filament.

About 1/6 of the way into a roll of PETG (and maybe 4 hours into a 6-hour print), an over/under wrap brought things to a screeching halt. I aborted the print, then snipped the filament and started unspooling it, looking for more cross-wraps. I found a ton of them, along with a ton of kinks.

I stopped about 1/3 of the way into the spool, still finding kinks and cross-wraps, and said to heck with it. The only way to use it would have been to run the entire length onto another spool, carefully avoiding cross-wraps, and hope the kinks wouldn't affect the print quality.

I complained to the supplier but never even got a reply, so now I'm wondering if this is just one of those things I can expect from time to time. Any thoughts & opinions would be much appreciated.

Cheers,

Glasseyed

Sorry to say it, but MOST wrap-unders are caused by end-users releasing the free end of the filament when handling the spool. It is mathematically impossible to introduce a knot during initial spooling, and all the reputable filament vendors these days have pretty careful free-end control when the spool is taken off the spooler and sent to packaging.

Where you may get knots straight from the filament vendor is if they're respooling very carelessly and let go of the free end. You should only see this with very cheap filament.

So, it's possible that your vendor messed up, but you should probably rule out your own handling practices first. It's not hard to prevent losing the free end. The nicer spool styles these days have holes on the side-flanges for securing the free end during handling/storage. Or you can print one of many, many filament clip designs from Thingiverse or your favorite model site.

If you're very careful with handling and still get knots, switch suppliers. Anyone sloppy enough to repeatedly mis-handle new spools is likely also using extremely cheap material, and there have been a lot of anecdotal reports of very nasty industrial chemicals being mixed into the colorants of low-cost filament.


LCD/DLP resin curing system I'm trying to develop a device to burn a glass slide surface with a special pattern of UV light (between 300 nm and 360 nm) in a 5 cm square surface.
I've read several threads asking questions about LCD printers and their way of functioning but I am not entirely sure how they work. So far I have found two methods that explain LCD printers:

The LCD screen emits light in UV spectrum that causes the resin to cure. I don't believe there are any LCD screens that can emit at 360 nm.

Initially there's a UV light bulb 'behind' the LCD screen which is translucent when off. The pattern is drawn in the LCD screen interfering with UV light's path drawing the image in the plate.

If option two is the right one, do you know any devices (uv light and lcd screen) to develop what I want within the 360 nm wavelength?
Alternatively, can a DLP projector to emit UV light (by adding a UV light bulb)? Would it still need to be cured?

It's almost always what you call system 2:
The LCD screen is acting as a "mask" for the UV backlight, which is a strong bulb under it. This also is the reason that the screen degrades over time and that the machines need replacement bulbs: the heat from the UV source burns out the screen and itself over time. Both parts are consumable, just like the screen.
You could technically swap out the light source for any one that fits the machine. However, a 360 nm light source won't help you for printing resins at all: most resins you can buy cure between 395 and 410 nm.
Yes, even by curing with an UV light source, you need to post-cure the print. The reason for that is to get rid of any uncured, not washed away resin that still sticks to the surface and that a 3D print right of the platform actually isn't cured fully - especially the inter-layer-bonds are not formed fully and curing in the lightbox increases the stability to the print a lot.


How does slipping Bowden tube affect retraction or does it at all? I have an Ender 3 Pro with upgraded Bowden capricorn tube. The tube will move approximately 1-2 mm during normal operation, though it will not come out of the coupler at all. I have read that the movement if unchanging (constant movement of 1-2 mm) can be compensated for with settings adjustment to avoid retraction issues such that it will extrude or retract "that much less"... I do not understand how this is possible...

Im confused by comments that a slipping Bowden tube on the extruder side only, say by up to 2 mm, is "lost retraction"... I have this problem too with the Bowden tube only at the extruder end, not the hotend, and wonder if it is really an issue at all. Here's why...

The filament is in direct contact with the gear and wheel of the extruder. If the Bowden tube is only moving in/out of the extruder end of the coupler, there are no "gaps" being created to cause leakage of the filament, etc on the hot end...As the extruder is either pushing or retracting, the filament inside the tube is still moving as much as intended regardless of the amount of play of the Bowden tube... no? therefore, retracting will not be affected at all, nor would the extruding process. Am I wrong and if so, can someone explain to me how this would be?

Note, I can see that this movement may cause under-extrusion on the feeding side process, as the machine is expecting say, 0.5 mm extrusion, but then has to compensate (unknowingly) for the slipping out tube during the "push", so not enough gets "out", but should not affect the retraction amount as the filament is still being pulled directly from the gears/roller.

Am I wrong and if so, can someone explain to me how this would affect the retraction along with the under-extrusion?

The slipping does result in lost retraction distance. It does not result in underextrusion, lost material (except possibly via having insufficient retraction after the reduction), or anything like that.

If your retraction is set to 6 mm, but the bowden pulls 2 mm into the coupler when you retract, those first 2 mm of filament motion do not pull the filament out of the hotend at all. The position of the filament relative to the tube (and thus relative to the nozzle) remains constant. After the tube can be pulled back no further into the coupler, the remaining retraction pulls the filament back through the bowden tube, for 4 mm of retraction at the hotend/nozzle.

When unretracting, the reverse happens. The first 2 mm of extruder motion push the bowden tube out of the coupler, and don't move the filament relative to the tube (or the hotend). After that the next 4 mm push the filament through the tube and back to the nozzle orifice.

The result is the filament ending up back exactly where it started, but having backed out only 4 mm from the nozzle, not the requested 6 mm.

These numbers are just examples but probably about right. If you put the plastic clip on the pneumatic coupler, the slipping should stop, but you can also just increase retraction if the amount after the loss to slipping is not sufficient.


Smoothers for TEVO Tornado printer I have a TEVO Tornado (bought quite recently) and I want to know what is the best type of smoothers MKS smoothers or TL smoothers? Are they the same thing?

The use of smoothers totally depends on the stepper drivers you are using! Note that the TL and MKS smoothers do exactly the same thing. Both use an arrangement of 4 or 8 diodes. Details of the problems with drivers and the working of the smoothers is explained in this blog post. The problem is that some stepper drivers are not able to produce low currents as of the present dead-zone.

if we had a way to modify the motor so that with a voltage of 1.4 V there would be no current flowing, then the driver would be able to generate all the currents because it would always be spitting out more than the minimum voltage

The diodes prevent current to flow at the cost of a voltage drop; a 1.4 V voltage drop (2 diodes) would prevent current to flow, as such you see diodes in series on the smoother boards.
These MKS/TL smoothers help with smoothing out the signal going through stepper motors; e.g. the notoriously noisy DRV8825 motor drivers are known for a stepped sine curve rather than a smooth output.
More modern chipsets such as the TMC21xx, TMC22xx, and TMC51xx do a much better job at providing smooth signals, and surprisingly, so do the cheaper drivers like the A4988s!
So if you are using stepper drivers that do not produce a smooth sine wave, like the DRV8825 stepper drivers, you could potentially benefit from installing smoothers. This could help with salmon/zebra skin/moire and ringing print artifacts/defects.
To quote the popular All3DP 3D printing site from "TL Smoother: Should I Add One to My 3D Printer?":

It’s a yes if you’re running DRV8825 stepper drivers. This was
what TL smoothers were designed to do: fix a design flaw in the
DRV8825. Your mileage may vary based on your printer’s power supply,
but you’ll likely see noticeable improvements in print quality.
It’s a no if you’re running newer Trinamic stepper drivers.
Trinamic drivers have many “smart” features built in that don’t suffer
from the same issues as the DRV8825 and already counter electrical
noise. As a post from Trinamic notes, adding TL smoothers doesn’t
provide any significant benefit; it only increases power consumption
and heat generation.
It’s a maybe if you’re running other drivers. Other stepper
drivers might not have the DRV8825’s design flaws, but they may
benefit from the slight electrical dampening created by the TL
smoother’s circuit. Considering the smoothers’ low cost (~\$8-15 for
packs of 3 or 4), it doesn’t hurt to try it out and let the results
speak for themselves.


Difference in weight from Cura to printed model I've recently switched to PETG , and I'm using Cura as slicer and Ender 3 as printer.
I'm printing a model which Cura declares to be 35 g, but if I weigh the printed model it weighs 23 g.
I'm printing with just 1 line of skirt, so its weight is negligible on total weight.
I've replaced the stock plastic extruder with a double gears metal extruder (3Dman 11 Dual Gear Extruder ).

I've also replaced the stock springs with metals ones.
I'm not having a quality problem, just I want to understand if this difference is caused by a bad configuration that could be improved.
Which are the corrections/checks that I need to do in my setup (both printer and Cura) for fixing this difference?

The density of the filament can be specified in the material model of the filament in Cura (Preferences -> Configure Cura... -> Materials and click on the material/filament you are using to slice your model for PETG), look at the value behind Density, the PETG filament I use is using 1.28 g/cm³ (PETG Economy Black -> Specification >).

This field is user editable, so you can change it to your needs. Cura calculates the weight based on the deposited volume.


Over-hangs in prints I would like to ask this in more of a general sense than anything, just for people to make note.

I am printing out things for people and some files have some edges hanging out the side. I always worry, since it is printing in mid air, that it would screw up the print. But I was able to go, maybe 1mm(I am not to good with metric when it comes to guessing). My question is, how far at 90* from a wall can a printer pull off before it is necessary to have support? This would help me when slicing up files.

It is typical for a 3D printer to be able to manage one-half the width of the nozzle for unsupported layer printing. This frequently calculates out to a realistic 45° from the start point.

If you are getting 1 mm extension from a 0.4 mm nozzle you are doing well. It's possible that the layers are not strongly bonded at the point of extension from the vertical wall, but are then strengthened by the layers printed above, if they do not extend excessively.

If your part is designed well, the extension will be distributed gradually over more than one layer, allowing that 1 mm extension over 2.5-3 layers without impacting the appearance of the model in an excessive manner.

The above does not apply to bridges, as it involves a different dynamic for the printer/slicer software.


Ender 3 Pro Filament extrusion problems I run quite a few Ender 3 Pro's using the same slicer settings (Simplify3D), and just recently I have noticed a very odd extrusion problem.

I find that at about the same height on several printers the printer under extrudes by quite a margin. After that, it either continues to under extrude for the rest of the print or it will go back to extruding proper amounts of filament with no problem. This destroys the print and makes it both structurally weak and defective. I am wasting quite a bit of PLA trying to fix this problem so any help would be appreciated.

Here is what I have done so far:

I first made sure that the hobbed gear is clean.
I tried extruding the filament with a very hot temp (240C) there were no problems here and the filament extruded fine albeit, it was not on the bed, just extruding into the air to see if the problem was heat.
I tried the same thing as above but with a low temp (180) this also proved just fine again extruding in the air.
I calibrated my E steps per mm, those are fine and accurate.
I tried increasing my flow rate to 118%
I tried switching to a different nozzle
I tried switching to a different hobbed gear
I tried switching the mechanism that pushes the filament up against the hobbed gear

That's about it. Not sure where to go from here so if anyone out there can think of anything I missed, I would love to hear it!

EDIT 1:

As per @fred_dot_u asked, the elapsed time at the layer of failure is roughly four hours in. I have also attached a picture of one example of this kind of failure below. I would also like to mention that this is happening on several of these printers as I have 18 printers running in one room. Our current theory is that the power draw is simply too high and so the printers are not getting the heat they need, however, the thermistors still register a solid 195C on my printers that are currently running.

EDIT 2:
Here is another picture of a different model with the same layer failure problem but at a lower layer height. This model was printed along with 11 other identical models on the same bed, all of which failed at the same height.

Based on the image and your report that the problem consistently appears at the same part of the print, this is clearly an (either absolute or net) underextrusion problem, but (mostly) localized to particular layers. I say absolute or net because it might be extruding too little total material, or extruding the right amount of material but losing some of it to unwanted extrusion (oozing/stringing) in the wrong places. Either of these could be related to geometry of the layers involved.

One factor here is probably coasting, which you mentioned in a comment you have enabled. The small amount of coasting probably means it's not a big factor, but coasting always underextrudes. That's fundamentally how it works. You should not need coasting unless you've disabled retraction for some reason; it's a hack that's a poor substitute for part of what linear advance does on printers that support it.

You also mentioned a 60 mm/s print speed setting. At 0.2 mm layer height and 0.4 mm nozzle diameter, that's 4.8 mm³/s volumetric extrusion rate, which is roughly the limit of what you can expect to achieve with your printer's hotend. If you try to print faster than the hotend can keep up with, the material won't melt sufficiently fast to pass through the nozzle orifice. This will naturally slow it down allowing further melting to take place, but in the mean time the extruder gear will either grind into the filament or (much less likely, I think) the motor will skip steps.

Note that print speed settings control maximum speed, which is why you won't necessarily hit problems from having them too high right away, but only at particular layers. In prints with small details, especially with sharp corners, the majority of the printer's time is spent accelerating and decelerating between speeds far lower than the nominal/max print speed, and if you only reach an excessive max speed momentarily now and then, it might not continue for long enough for the material to cool down, in which case everything just works out.

Part of why I mention this is that, if you're trying to keep print time under control, setting a higher max speed might not even help you. Usually acceleration/jerk is the limiting factor to how fast you can print. Max print speed should be set according to the extrusion rate the hotend/extruder can keep up with, and print acceleration/jerk should be set according to the dynamical properties of the printer's axes. If you increase them too much you might get rough surfaces, ringing, or even skipped steps/layer shifts, but you can go pretty high. 3000 mm²/s is probably the absolute max I'd try on an Ender 3. I did this and had some success, but some failures; I don't recall what jerk was and it might have been a factor too. The Y axis in particular can't handle acceleration as well as the X axis can, due to having to move the whole bed, not just the hotend assembly. Somewhere between 500 and 2000 is probably reasonable, but I'd experiment a good deal before trying it on a long-running print.

One additional method to increase speed might be reducing line widths to less than the nozzle width. This proportionally decreases the volumetric extrusion rate the hotend has to keep up with. But I'm not sure how well line widths less than nozzle width work for outer walls. This may adversely affect part strength too, which might not be a problem for your particular usage case.


How to keep Z-axis motor from slipping when powered down Because of the weight of my Z-axis and the relative ease of its motion, when the Z-axis motor is powered down the bed has a tendency to slip and fall down.

Obviously leaving the motor powered solves this problem, but that is not ideal.

I am looking for some kind of solution that passively stops the Z-axis motor from slipping; some kind of brake or clutch. Ideally I'm looking for something that I can add onto my current motors and that I could print myself. Commercial solutions (preferably ones that could be replicated with a 3D printer) would also make valid answers.

The simple way to do this is to use a self-locking screw pitch. Pretty much any single-start thread using a sliding nut cannot be back-driven so the load will not fall. Normal 8x8 trapezoidal thread screws will easily back-drive because of the steep pitch.

Likewise, a worm drive between the motor and Z stage will hold the load. You would want to switch from screws to belts for the main motion stage in that case though, to avoid having too much total gear reduction.

Both of these solutions will limit your maximum Z speed, of course. But they're simple and reliable. Clutches and brakes add a lot of complexity and must be actuated somehow. Designers who want the load to stay suspended almost always simply use single-start screws.


Monoprice Select Mini V2 retraction/stringing problem I have a Monoprice Select Mini V2 and I’ve recently been having issues with little strings that are thick and sturdy sticking off of models:

I used Ultimaker Cura v3.4.1 to slice this model: Basic Retraction test using Hatchbox Black PLA filament

And the following settings:

Layer Height: 0.1313 mm
Wall Thickness 1.05 mm
Infill: 22%
Extruder Temp: 200 °C
Bed Temp: 55 °C
Retraction Distance: 4 mm
Retraction Speed: 40 mm/s
Speed: 50 mm/s
Z-Hop When Retracted: Off
Supports: Off
Adhesion: Brim

I’d appreciate any advice on how to fix this problem.

The Monoprice Select Mini V2 uses a Bowden style extrusion system. Bowden extruders compress the filament in the tube where the gap between the filament and inner tube diameter allow for the filament to buckle slightly and compress causing a pressure build-up in the hotend. Without retraction this implies that the filament will start to ooze out of the hotend once you stop extruding.

From your settings can be seen that you are using retraction. The question now arises whether you retract enough? Furthermore, this stringing can be reduced by setting the correct settings for e.g. print temperature, retraction, coasting, travel speed. It is up to you to find the correct settings; test print objects like calibration prints (like in the image you showed) help you with finding the correct settings.

Apparently, the retraction you use still allows for some filament to ooze out of the hotend as shown in your image. This means that prior to the travel move there is still some pressure left in the hotend. A parameter that reduced the pressure prior to the travel movement is called "coasting"; basically you define to stop extruding while the head is still completing the printing moves prior to the travel move. It is advised to explore this setting. Other options to investigate further include lowering filament print temperature or increase travel movement.


Ender 3 stock Bowden tube inner diameter? Worth upgrading? I recall hearing claims that the Ender 3 (maybe only newer units?) has a narrower Bowden tube than some printers that helps with flexible materials, but I can't find any authoritative figures. Does it come with a standard 2 mm ID tube that would likely benefit from replacement with a 1.9 mm or smaller (Capricorn one seems popular), or is the stock tube already comparable with these lower-clearance ones? I'm looking to improve speed and quality with flexible filaments and trying to determine if upgrading (and at the same time, shortening) the Bowden tube is a worthwhile direction.

I disassembled the hotend side of the Bowden setup to check for deterioration (and found an actual hole in the tube!) for the first time since getting a decent caliper, and after making a clean cut to remove the damaged part, measured the inner diameter at 2.19-2.21 mm. I'm not sure if that's enlarged from wear or the original size it was manufactured as, but either way this suggests that upgrade to Capricorn at 1.95 mm (±0.05 mm) inner diameter should make a significant difference vs my current Bowden tube.