How to feed the filament through the material shortage sensor? I'm just finishing the set-up of a CR-10 Max. It is a new printer.
I don't manage to feed the filament through the material shortage sensor.
I can hear the micro switch click; the LED turns blue, then a few millimeters after that (33 mm total from the entry point), there is something that prevents the filament from going forward. I don't see any switch on the outside of the sensor, and I applied a reasonable amount of force on the filament.
Can you tell me how to troubleshoot this ?

I've designed similar sensor casings, sometimes the filament catches a ridge/ledge or part of the cavity, even when it is chamfered or rounded. The arm of the limit switch pushes the filament up, away from the filament straight path.
Have you tried cutting the filament under a very sharp angle, that may work.


Can UV cure inside opaque or more massive printed object? From what I understand, UV curing of resin prints works by starting a chemical reaction that hardens the resin permanently.

Also, a curing step after print is needed to speed up the print and also to reduce the curing during print, which would cure resin beyond the current layer.

However, what is the transmissivity of UV light in partially cured prints? If I print a more massive object, or if I use an opaque resin, how deep will the object harden properly? Absorption is always exponential, meaning that it decreases quickly with depth.

Depending on the resin, how thick prints can be effectively cured? This information is not provided with the resin, which I actually would expect from reputable manufacturers.

From what I know about the various resins, once they are printed they are cured enough. Some of the transparent ones require additional curing, however the manufactures of the machines only test based on the max size that their machines can print.

The resin never stops curing apparently, going into diminishing returns; curing slower and slower as time goes on. Only way you will know for sure is by experimentation. You should get a poly-carbonate tube, place black tape along one side then spray paint the rest black. This will leave a window that you can use for future observation. Seal the bottom, and pour in uncured resin. Leave it under a UV source for 2 weeks then peal the tape off to see how much of it has cured. Then come back here and ask Trish to do the math on what the co-efficients of absorption are for the material :)


Printing with colorfabb XT fails after several successful layers I'm printing parts for a HEVO (HyperCube Evolution CoreXY), using Colorfabb XT filament. After several successful prints. I'm having a lot of failed prints. They start off pretty well but after ~15 layers the filament starts to string and blob.

Printer details

Model: RepRap i3
Extruder: E3D 1.75 all metal hotend.
Nozzle: .4
Print temp: 260°C (max. recommended).

Steps I took to troubleshoot

First I thought my nozzle was clogged. But it's not I can push the filament by hand without issues.
Lowered the speed to 35 mm/s.
Disabled retraction / disabled part cooling.
increased the max temp with 10 % to ensure the filament flow

Printed parts that fail:

Note: the two parts on the left are printed in one job

UPDATE 26/07
Dit a few more prints with PETG to eliminate the moisture problem. Same results.

This looks a lot like under extrusion caused by heat creep.

Heat creep is when the nozzle temperature 'creeps' up through the filament and makes it melt (a bit) and form a blob (or just widen enough to get stuck) a centimeter or two before the nozzle.

The characteristic is usually that everything works perfectly well for some quite fix amount of time, then there is severe under extrusion.

Solutions:

Lower the temperature (yes, as then the heat won't creep as much!)
Add a fan cooling down the cooling part of the print head

I have the same print head as you it seems (E3D 1.75 all metal) and I had heat creep when I changed the fan to a less noisy one (but also less effective).


Ender 3 seemingly speeds up too much on straight long shell lines After few good prints with my new Ender 3, I noticed that prints with longer shell straight lines (> 5 cm) have extrusion problems in the middle of those lines.

I figured that this might be because the printing speed (70 mm/s) and filament temperature (210 °C for PLA). So I increased my filament temperature about 215 °C and lowered print speed to 60 mm/s. I am using Cura v3.5.1. For the next few smaller prints everything was perfect.

Now I am printing a bigger 128 mm X 48 mm rectangular shape. In the middle of the 128mm line of the outer shell, I have signs of under extrusion. Looks like dents.

I also notice that the head is really fast during this 128 mm travel. No way ~2 seconds would take 60 mm/s to travel 128 mm. It is more like 1 second or less.

Why would my head travel at such speeds?

I am attaching my speed settings.

I am attaching the image of the printed piece and the defect generated.

Your travel speed is set to 120mm/s so it would make sense the 128mm travel takes ~1 second. You most likely have combing turned on so that it doesn't not need to retract on travels. This makes it ooze plastic as it travels and would mimic underextrustion.


Is it safe to print a rotor insert for a centrifuge using a makerbot? Laboratory centrifuges have buckets that hold the sample tubes in inserts.

The buckets are the black things on the rotor in the upper left corner holding the bottles. Examples of inserts are shown below (the colorful containers with slots for tubes). These fit into the buckets and I'd like to print them since these are expensive.

Is it safe to 3d print these using a makerbot given the g-forces these rotor inserts will be subjected to (potentially 150g's under our settings), or will the inserts deform and unbalance the rotors under the stress?

Additionally, is the precision of the printing good enough that the inserts can be expected to be well-balanced (the correct weight, with a symetric design having even weight distribution)?

We have a basic makerbot that makes little plastic robots.

It's difficult to determine if the buckets are fully enclosed, but I suspect that they are. The enclosure into which the inserts are placed will provide some structural support.

3D printed objects have relatively low torsion strength, but a reasonable compression strength, especially with high infill levels. One could consider that the item placed into the insert will transmit force to the bucket, but likely not compress to the point of destruction.

Allowing also that the forces on a swinging bucket centrifuge are "downward" or when in use, "outward," the primary location of force will be the bottom of the insert you create. It appears that the main function of the insert is to keep the tubes separated, rather than to keep them supported.

Create your inserts, but leave an open bottom. Attach a suitably strong panel to the bottom of your created model with epoxy.

Another thing to consider in this project is the mode of failure. What can go wrong? The tubes in the insert should not explode, but if they do, is it merely cleaning up that follows? I suppose one aspect of the inserts is to keep the tube walls in column, to keep all forces linear to the tube cylinder, rather than out of line. It's easy to keep pennies in a stack under pressure, but don't push on them edgewise.

You can and should perform a test on a 3D printed insert. Make one that is relatively flimsy, say a six-tube unit and spin it without tubes in place. Test it prior to the spin for tube fit, then test it after the spin. If there is deformation, you would not be able to insert the tubes after the spin.


Why does my domed print have a thin shell? I am making a "fun button", with a dome-shaped top. The vertical sides, top center, and raised lettering seem fine, but the more sloped outer parts of the dome are very thin, with some gaps and the infill pattern is quite visible. It's almost like the slicer isn't recognizing the sloped part as an exterior shell.

What is causing this, and how can I fix it?

The model was made in Fusion 360, sliced in Repetier with Slic3r, and printed on a Monoprice Maker Select Mini.

Edit: More information after checking values used and taking more photos.

This was my second attempt, after increasing the shell count already.

On my first print, I clearly had a low value for horizontal shells, top and bottom were both at the default of 3. I upped these  both to 8. (Layer height is 0.13125.)  The bottom of the button is now good. The "good" center area extends a little further out, so I think it's probably thicker up at the top of the dome. But the sloped sides are pretty much the same - this is why I'm thinking it's not being considered as a "horizontal shell".

Comparison:

There are some design iterations, but the top surface is the same shape.

Update:

I did a print using Cura, with 0.8 mm shells, and it looks great!

I cut the two bad prints with a hacksaw to see a cross-section. The bottom is clearly thicker. The top on the outer infill void is pretty much the same. The top on the other void is thicker most of the way across, but suddenly changes to thin.

Slice with more solid top layers. I always use five with low-density infill.


Keeping my filament spools from getting knotted? This is something I've ignored for awhile, but it keeps cropping up, and occasionally, if the filament snags real good, it can mess up a great print half way through, etc.

Basically I have my filament spools hanging on a PVC pipe mounted directly above the printer, and the printer just sucks it in from the spool, but occasionally it becomes knotted at the spool, or becomes otherwise tangled.

I'm thinking even if I completely unwrapped and rewrapped all of my spools so there was no trace of a tangle, what's to stop it from happening again? -- What's a good strategy for managing this kind of issue?

Edit: From some of the answers below, it seems that maybe the travel of my X carriage back and forth could be why my spools keep getting tangled. -- It looks like many people have their spools at about 90 degrees from mine (rotated relative to the Z axis of the printer), so that the travel of the X carriage won't have that affect. -- Also guides, etc are probably a good idea.

Here's my current setup for reference (filament removed):

When I first set up my printer, the spool was able to spin freely. Filament was making loose coils on the outer layer of the spool. Snags happened frequently. I decided that not allowing the spool to spin faster than the rate draw of the filament might improve the way the filament was feeding.

I put more physical distance between the spool and the machine. The filament stopped bunching up in loose coils on the surface of the spool, and the snags went away. The increased amount of slack between the machine and the spool seemed to absorb the "overshoot" of the filament draw and the spools became much better behaved. I also was able to run the spool down to the end more consistently than before.

Not everyone has extra room to use, and not all extruders are conveniently oriented, so moving the spool further away from the machine won't work for everyone. I believe a guide or some sort of dampener would serve the same function, if the underlying problem is the spool loosening up enough to where loops of filament get caught under others and then snag. What worked for me was to stop the spool from "racing ahead" of the rate of draw and loosening up enough to snag.


Order in a line command in G-code I've started learning G-code for 3D printing and I'm quite confused.
I'm using an Ultimaker S5 printer and the firmware is : 5.5.12 - 20200226-UltiBot

Is there a difference between G1 F1200 X188 Y92 E0.01 and G1 X188 Y92 F1200 E0.01?
Most of my code looks like: G1 X[coordinate] Y[coordinate] E[num] without Z!
How is this possible?! My model is a 3D-model so how come the letter Z appears about 5 times in tens of papers?

Any help would be greatly appreciated!

I haven't used every flavor of gcode or firmware, but I've never seen the parameter order be important, provided that:

The G or M code was the initial entry; and

Each parameter was clearly listed with one or more spaces between parameters; and

No spaces were in between the parameter letter and the value.

We use a custom version of Repetier firmware to run 3D printers and Fadal CNC machines, and in every use  G1 F1200 X188 Y92 E0.01 would be evaluated and executed completely identically to G1 X188 Y92 F1200 E0.01
Nearly all gocde variable values are persistent, so if Z remains unchanged because it is only specified once per layer, or if Z remains unchanged because it is explicitly specified (with the same value) on every line, there should be no difference in the behavior of the printer.


Evidence of a warped build plate? The first layer is very patchy indeed.  I've calibrated the build plate pretty accurately but even if it was a badly calibrated build plate I don't think it would have this effect.

It doesn't seem to have a negative effect on the print.

Should I be concerned about this?
Is this due to a the build plate fault?

It looks like your first layer is way too close to the bed. The printer is trying to squash the plastic down very thinly, resulting in inconsistent extrusion. You will likely see better results if you move the nozzle away from the bed a little bit. Increasing the thickness of the first layer might help as well (this is a setting in your slicer).

Keep in mind that if you're trying to print (e.g.) a first layer with a thickness of 0.05mm then a 0.025mm variation in the height of the build plate will result in very strong variation in the thickness of the extrusion on the first layer; in some places it will only be half as thick as in other places. If instead you used a 0.2mm first layer, then the 0.025mm variation barely makes a difference.


X and Y axes don't move after upgrading to TMC2100 drivers I had noisy DRV8825 drivers for my extruder E0 and X, Y, Z axes. I upgraded all to LV8729 drivers but they were still noisy, so I bought two TMC2100 drivers for the X and Y axes and two LV8729 for the Z axis and extruder E0. I updated Marlin (reversing endstops logic and choosing driver types) and I removed the jumpers under the driver pins. But my X and Y axis don't move; eventually the printer halts.
What could be wrong?

Steps/unit also must be modified. In my case these values made the printer run silent and smooth.
#define DEFAULT_AXIS_STEPS_PER_UNIT   { 100, 200, 6160, 884 }

I set Max feed rate and Max acceleration as below:
#define DEFAULT_MAX_FEEDRATE          { 300, 300, 5, 25 }
#define DEFAULT_MAX_ACCELERATION      { 300, 300, 100, 10000 }


Problem with the first layers on the print I ran out of ideas on what could cause my problem.

Ender 3 Pro
Nozzle temp 200 °C
Bed temp 60 °C
PLA filament

Please look at the pictures. The first layers don't look nice. The top and the sides are perfect.
This happens in every print. With and without raft or brim. The strange thing is that raft and brim looks very good on the bedside. Is there some settings I am missing out on here?
Tried with Creality Slicer that came with the printer, and the Ultimaker Cura slicer.

The filament is not flattened, it looks like the nozzle deposits round filament strings while in fact they should be flattened more. This usually indicates that the nozzle to bed distance is too large. A perfect distance is obtained with plain A4 or US letter paper (usually 0.1 mm thick; or 0.004") during levelling where there is a slight drag/friction force observed when the paper is pulled between bed and nozzle. Alternatively, you can use feeler gauges:

Considering that the raft is printer well, it could well be that the initial nozzle to bed distance is correct, but the distance between the raft and the first layer of the product is too large.


Anet A8 extruder is clicking and not extruding I was printing with my Anet A8 and it pulled the filament spool off of the shelf I have the printer on and forced the filament out of the extruder. I took apart the extruder and removed the debris that was left inside, re-leveled the bed and tried to start another print. When the extruder tries to feed the filament it makes a clicking sound and won't extrude. How do I fix this?

There are a number of unanswered questions which may serve as a guideline to narrow down a solution.

Instead of attempting a new print, consider to remove the filament again. Shine a light from below and look into the barrel of the extruder to determine if you can see light. If this is mechanically impractical, move to next option.

Manually feed the filament into the extruder. Use the panel to advance the filament rather than creating a print. Does the filament feed properly?

If yes, the problem is not in the extruder system, nor the heat block or hot end. You said you re-leveled the bed. Double check that the nozzle is not being blocked by the bed, preventing filament from extruding.

If the filament does not feed properly, you may not have completely cleared the heat break, hot end, or nozzle. If you can get or have nylon filament in the correct size, perform a nylon cleaning operation. This involves removing the existing filament, raising the nozzle temperature to 240°C while pushing nylon through. You have to be able to manually force the filament through until you see only clean nylon from the nozzle.

I have had to push nylon in at the correct temperature, then pull it back out without any extrusion due to the depth of the blockage.

After you've pushed as much as you can to get clean nylon (or none), cool the hot end to descend below 140°C. After a moment or two, set the temperature to 140°C and forcibly remove the filament from the upper portion of your assembly. It may require pliers and substantial force to get this out.

Repeat the heating, extrusion (or attempts), removal until you get clean nylon from the nozzle and clean nylon at the tip of the removed filament.

Only just today, I had to clear my nozzle using this method, but I was unable to get a reasonable extrusion of clean nylon. I have a 0.4 mm nozzle drill and applied that to the tip of the nozzle, carefully.

I found a burned on segment by this additional step and succeeding nylon cleanings went well and my nozzle is printing cleanly again.

If you don't have nylon, you can perform similar cleanings (called cold pulls) with ABS or PLA.


Bed is leveled and not warped but still uneven printing? I have the Creality CR-10S. I replaced the glass it originally came with as it was warped and I wasn't getting any material out on 2 of the sides.
I switched to a PEI sheet and got the same results after only a few prints.
I then switched to a mirror I had cut previously, and it worked for maybe 2 days. I scrapped a print off that warped, and then the leveling was off on that. My gantry is level, my beds aren't warped, I'm leveling it to allow a standard piece of paper to have friction by the head. It's either to close and no filament is extruded or it doesn't stick at all and drags filament everywhere. If I can get good extrusion on one side, it's horrible off on the other or all corners.
Note that I have checked my gantry and it is straight as well and my the bed. Not sure what issues I have left.

Be sure that you have no previous bed meshes saved and automatically applied: use the commands M502, M500.
Once you have done that, try this technique:

It's about using a ruler to detect areas which are lower, and then use stickers below the glass to thicken those areas only, resulting in a much flatter surface.
If you don't want to use the blue tape (which will worsen the heat transfer, but not so much after all) you could use 0.3 mm silicone thermal tape, which is more heat conductive but it's also quite thicker than blue tape.
This other alternative consists of flattening the plate itself, but it's inevitably performed when cold, while the tape technique above can be performed at the desired temperature (since the warping may not be constant).


3D printer destroys part by lowering nozzle I have a Lulzbot TAZ 4 and am using Lulzbot Cura for slicing, printing with HIPS.
Yesterday, I tried a print, only for this to happen:

It appears that the printer got most of the way through printing the part, and then for no apparent reason lowered the nozzle into the part (causing it to detach from the bed), raised the nozzle back up, and then to continue trying to print like nothing happened.
I thought maybe the G-code file got corrupted when transferring to the SD card (a single bit-flip could cause exactly this problem). So I generated the G-code again with exactly the same settings, and the same thing happened again but in a slightly different place and a few layers further up the model:

I have previously printed exactly the same model, only mirrored, with the same settings, and did not have this problem. I've never seen anything like this. Does anyone know what is going on?

This is my bet, based on cooling fan failure (I assume it was nozzle fan, not a heatsink fan), though honestly my practical experience with HIPS is zero. Without this fan heated material printed at high angles will definitely curl up, and even flat may be unstable. I suppose it happend, observing layer inconsistency on middle finger close to the nail.
Then, material could curl a bit and build up. Collisions with hotend could result in blob of plastic here or there, and then something bad happened (see @Jack State comment).
I also suppose that the whole print was detached from bed and rotated, because we see surprising shape across the middle finger, and unfinished index finger. Filament was extruded in random locations, causing more blobs, more curling and more mess. There are some gaps which look exactly like hotend run directly into them. I suppose that object rotated both horizontally and vertically. It could be even dragged by hotend at the end (e.g. filament was extruded inside the index finger).


Monoprice Select Mini v2 reattach boden tube to feeder head I have a Monoprice Select Mini v2.

The Bowden tube has detached from the filament feeder head... it was actually pushed out by the filament (175 PLA) as it fed.  It appears to have been held in place by a compression fitting inside the feeder head. I think the blue plastic collar provides the compression but I hesitate to attempt to remove it for fear of making matters worse.

Looking for advice on getting the Bowden tube and compression fitting back together without wrecking the feed

I had a similar issue with my bowden feed system, those could be the reasons:

the pneumatic connector is not keeping the pressure on the pipe -> replace
the Teflon pipe is faded/worn -> try to cut the end of the pipe
the hotend/nozzle is clogged -> clean/replace
the pipe is excessively bent and gives a lot of resistance -> that usualy needs pipe/tube replacement.
the nozzle temp is to low -> increase printing temperature

In some cases I had to cut the tube above the pneumatic connector and push it down to get it out as there was no way to  pull it back from the collar.


Makerbase MKS Slot2 V1.0 + RepRapDiscount Full Graphics LCD + RAMPS 1.4 I want to add an external SD card adapter on my RepRapDiscount Full Graphics LCD. My 3D printer is based on (Arduino Mega + RAMPS v1.4 + RepRapDiscount Full Graphics LCD).
I buy an SD Card Adapter from Aliexpress  (https://www.aliexpress.com/item/32873382195.html?spm=a2g0s.9042311.0.0.4f544c4d5UzB1L) and now I want to add this adapter on my RAMPS 1.4 while not disturbing the working of RepRapDiscount Full Graphics LCD.
Please guide me how can I add this to my RAMPS? Thanks!

My 3D Printer Details:

Model: A Standard DIY Prusa 3D Printer (Cartesian)
Firmware: Repetier Firmware

A RepRapDiscount Full Graphics LCD already has an SD card slot reader at the back of the board:

Basically one of the 10 pin headers is used for the display and rotary encoder and reset, the other header is used by the SD card reader.

The module referenced in the question is a breakout SD card slot reader for the TFT (touchscreen) display controllers. Whether these are compatible with the EXP2 header of the RepRapDiscount Full Graphics LCD should be compared with the schematics. The schematics of the RepRapDiscount Full Graphics LCD are available, but for the SD slot breakout cannot be found. It is therefore unsure if the EXP2 is fully compatible for the SD slot board. To use the EXP2 on a RAMPS shield, you need the L-shaped connector.

The description of the Slot2 explicitly says that it is meant to be connected to either a TFT35 or a TFT70 MKS touchscreen display. In order to use it directly to your RAMPS shield requires finding out which pin goes where.


Tryinng to get CAELinux to boot I believe that CAELinux has successfully installed on a SD card on a laptop. When I rebooted what I am left with is a GRUB prompt. If I enter the chainloader command it expects things like the device name of the linux image. I really want to know if CAELinux has installed and if it runs OK. Then I shall learn more about GRUB because I have another distribution that I am interested in.

How can I simply start CAELinux from the GRUB prompt?

Per the Getting Started page,

  As CAELinux is a customized Xubuntu 16.04 distribution, the installation instructions (and then administration) for Xubuntu/Ubuntu  all apply to CAELinux.
  For more instructions on how to install CAELinux on hard drive, please follow the Ubuntu instructions here: https://help.ubuntu.com/community/GraphicalInstall

Based on the information provided above, I think this question is off-topic for this site, and should be migrated to either Unix & Linux, or Ask Ubuntu.


MINTEMP BED Fixed error when running consecutive print I am using "Pretty PETG" along with PrusaSlicer's consecutive print mode.
What I am noticing is that upon finishing the first print, the printer hits MINTEMP BED Fixed. I'm not sure if it's immediate because I let the prints run overnight but I assume the bed cools down and then the error is hit.
I'm just starting to learn G-code and my initial thought was there's an errant bed temperature instruction but the only M140 S0 instructions I see are in the end_gcode and near the bottom of the file. Maybe there a goto in G-code which may be running after M140 S0 which then causes the MINTEMP BED issue? Perhaps there's something else going on?

The bed minimum temperature is defined in your configuration file, e.g.:
#define BED_MINTEMP        5

If the error is displayed, it means that the measured temperature drops below this level.

What I am noticing is that upon finishing the first print

This could hint to a faulty heatbed connector where the connection is lost because the bed moves to the end positions (hard to say without seeing the end G-code).
Basically, you could have a connection to bed thermistor that is intermittently failing, or a bad bed thermistor. If connection is lost the temperature defaults to 0 °C or a lower setting.


Can a short-circuited heat bed be salvaged? I was working on my printer when something metallic came into contact with the pcb. I smelled smoke and quickly unplugged the printer. Anyway, this is the result and, of course, the heat bed won't heat.

Can this be salvaged or should I toss it and buy a new one?

update the heat bed was not hot at the time. I had the heat bed unscrewed from the chassis but had forgotten to unplug the printer. I am not exactly sure how it shorted but I think it shorted between the power lead connection and the thermistor.

What happend was short circuit of course. There is no doubt you overheated HB so copper detached from HB base plate. Because you wrote it doesn't work it means copper tracks are broken.

There is very low chance to fix it. I mean it - near to zero.

What you could do is:

Detach HB from arduino
Find a place where track is broken (which needs to uncover it from protective layer)
Connect it with a wire

Unfortunately even if you do it and your HB will work (electrically) your fixed HB which won't be flat anymore.

So definitely it's to be thrown away.

[edit]

I just realised you have double power HB, which means your HB has 2 heaters... which gives a bit hope.

take a look here

here is schematics which could give you an idea

You could check if your second heater works ok

If yes then you are salvaged! :)

[edit2]
I really suppose the schematics of HB is more or less like this

So if H1 is broken there is a chance to use H2 connecting pins respectively


Dead thermister or dead board on Ender 5? I have a base model Ender 5 with the silent v4.2.7 board.
Earlier this week during an overnight print, I came in to find it unfinished and powered off. I turned it back and it complained about an outage. When I started warming the hotend, it squealed and turned itself back off and then back on.
Now anytime, I try to warm up the hotend, I get the same.
I set up the printer to give data me debugging data via the console in Pronterface and in Simplify3D. I don't receive any kind of error, the printer just powers off and then back on.
I'm hoping that the thermister is just dead and I can replace it easily enough. What I'm afraid of is that the board itself is dead. BTW, I am able to warm up the bed with no problem, just not the hot end. Any insight would be appreciated.

"Heater core" wires are not the same as thermistor wires, are they?
Check if thermistor is properly connected?
Reading -14 C in my case always pointed a disconnection of thermistor. (I didn't had a case of broken one so far.) In case of short it would probably show som max temperature (my guess, I dont want to try), but it is always good to check if wires are do not touch each other and are properly insulated?
Measure thermistor's resistance
If you are able to use multimeter, then:

disconnect thermistor from the printer board
set multimeter to resistance measurement (200k Ohms)
connect thermistor and multimeter using wires - the ones having aligator clips would be the best
read resistance measurent

My spare shows 97k Ohms in room conditions. So value should be high (you may refer to specs sheet of given type when in doubt).
Check that hotend is actually powered
If thermistor is OK, then indeed the hotend powering may be broken. Ths definitely require skills and may introduce many risks to electronics and maybe even to your health - but if you are skilled enough, you may measure with voltmeter if there is correct voltage provided to the hotend. For example the MOSFET on the board may be broken (I already replaced one in the past for my heated bed).


How to measure the nozzle diameter? On a Creality CR-10 Max, there is a bag of unidentified spares, which include three unmarked nozzles.
There is a needle that is exactly 0.4 mm in diameter, which needle fits exactly inside one of nozzles. It also fits loosely in the largest nozzle, which diameter looks like it's really close to 0.8 mm on my digital caliper. The smallest one has only room for the tip of the needle, and the digital caliper reads 0.34 mm on the tip of the needle when pushed from the inside of the nozzle.
I assume the sizes are: 0.8 mm, 0.4 mm and 0.3 mm.
Can you tell me how to measure the diameter with better accuracy?

I have found that normal measuring devices are not particularly helpful with accurately measuring nozzle diameters. But you're already off to a great start.
What is helpful is to take them somewhere that has a wide assortment of drill bits, and find which two adjacent sizes will and will not fit in the (clean) nozzle; then convert the diameters to mm (if needed), and your nozzle is larger than the small bit, but smaller than the large bit. From that, you should be able to narrow it down to a standard dimension.


Z axis issue with Ramps 1.4 I just installed a Ramps 1.4 board on to my Anet A8. Everything worked as it should except for the Z axis motors. The Ramps board I have contains two headers for each Z axis motor.

When both motors are connected, one of the motors squeals like something awful. When I disconnect one motor it turns smooth as butter. I have tried this for both motors and when only one is connected it works as it should but does not with both.

Has anyone experienced this? Is there a simple remedy for this issue? Any help is appreciated.

Found the issue. The steps were set way to high. I lowered my steps to 500 and the steppers seem to perform as they should.


How to straighten PTFE tubes? PTFE tubes are typically delivered coiled up. And because they are quite stiff, they always want to spring back to their original curvy shape, making them harder to route properly.

Is there a way to straighten them out?

I just plugged the ends of tube and soaked it in real warm water for 5 minutes then stretched it out on a table. That helped then the hard part I spooling it up against the arch and soaked it again. This seem to work the best.


Is inconsistent vertex density a bad thing? Will an inconsistent vertex density likely introduce artifacts in a print?  Or is it OK as long as it's a smooth surface?

For the most part, the exact level of vertex density doesn't matter too much. But it does depend on the slicer and settings. Some slicers (like Slic3r) will auto-decimate toolpaths to ensure that the rate of motion commands isn't too difficult for the old, slow 8bit processors in most consumer/hobbyist 3d printers. Having a large number of very small motion commands can bog down these motion controllers and cause pause-stuttering that creates little zits on the print. Most slicers simply reduce model detail level to safeguard the motion controller. Because the contours are decimated to a minimum motion segment length, very small model triangles are irrelevant to printer performance. At the most, they might add a marginal amount of slicing time.

On the other hand, some slicers (like Simplify3d) assume you have the correct level of detail you want in your model, and will pretty faithfully reproduce the model file's contours in the sliced toolpath. If your entire model is very high mesh density / poly count in general, or if your high-density mesh regions are crossed by a layer slice, this can produce a series of very, very short motion commands. Sometimes the motion commands are even smaller than the motion resolution of the printer, and simply take up processor time (to evaluate and drop from the queue) with no benefit to print fidelity.

In a more general sense, high-poly models are dramatically more difficult for the 3d printer to reproduce accurately. There are two big issues:

Each motion segment requires some processor time to read/receive, parse, and execute. But the shorter the segment lengths are, the faster the printer runs through them. A short move takes little time to perform but still has the same processor load as a long move. At a certain point, the processor can't keep up, and performance suffers. The printer may run out of queued moves to execute and pause in place, or it may violate acceleration limits and violently clunk through corners (or even lose position) because it didn't have enough time to iterate through the calculations that determine how fast it should move.
The algorithms used by most consumer/hobbyist 3d printer firmwares (Marlin, Repetier, Sailfish, Smoothieware, etc) are based on GRBL. And without getting into the math, GRBL uses the sharpness of the corners between motion segments to decide how fast to travel through the corner. So a 90 degree turn will trigger a considerable slowdown, while a series of small angles (such as many small segments comprising a curved surface) is not recognized by the algorithm, and it will try to barrel through the curve at full speed. On long, gentle curves, this is fine, but high-poly tight curves (such as a filleted edge or organic model detail) are traversed far too fast because no slowdowns are triggered. This means high-poly models must be printed at much lower feedrates / target speeds, because the acceleration algorithm can't figure out when to go fast or slow. Whereas a blocky, low-poly model can be printed much faster and the acceleration code will speed up and slow down as needed for good quality.

These are primarily issues with high vertex density versus low vertex density, not variable density. Small pockets of high detail are usually not problematic, as long as they are small enough that the motion planner queue (say, 16 segments) doesn't get filled with too many very small movements. A few small segments in a row is ok, but a few dozen is not.

These are limitations baked into the algorithms used by today's slicers and motion controllers. In the future, they may not be so problematic.


E3D Thermistor Alternative E3D hotends use a thermistor whose legs are insulated with glass fiber sleeving and clamped down with a screw and washer:

This solution enables the printing of high temperature materials, but it's a bit fragile and after reassembling the hotend a couple of times, the screw will have thoroughly mangled the thermistor's legs and sleeving.

Some knockoff E3D hotends use a (horrible) solution where the thermistor is just loose in its respective hole, and kapton taped to the heater cartridge wires which holds it in place:

This solution seems kind of ad-hoc, and I'm worried about the thermistor coming loose. One advantage is that it can be reassembled arbitrarily often, since just pulling out the heater cartridge also pulls out the thermistor without damaging it. Note that the picture shows PTFE sleeving which restricts the temperature, but you could easily use fibreglass in this situation as well.

Another solution is the stud thermistor:

It screws into the hole that is normally used for the clamping screw. Unfortunately you're limited to around 250C because of the epoxy used in the stud. I've also found that the epoxy fails after a while (regardless of temperature) and the thermistor isn't locked in place any more (it still works, by virtue of being constrained by the heater cartridge wires as in the previous solution but that's not ideal).

Are there any solutions, compatible with genuine E3D hotends, that:

are not limited in temperature by epoxy or PTFE,
can withstand being disassembled and reassembled better than the standard fiberglass sleeving,
is a bit less hokey than a kapton taping the thermistor's wires to the heater cartridge and hoping that holds it in place?

I like the mounting method on my Mk9 extruder: there's a small hole drilled into the heat block, parallel to the heater hole. B3 Innovations sells a thermistor packaged into a small spring. The whole assembly goes in the hole, and a setscrew (gently!) secures it. You could just as well put a bare thermistor into a spring or something similar; it's mainly to protect the thermistor from the setscrew, and from excessive bending.

From your photo, it looks like the same thing would work fine for your hotend.

However you mount it, adding some thermal grease can help conduction from the surroundings.


OpenSCAD library for empty space/holes I am working on a design in OpenSCAD, and need (would want) two things that seem tedious to hand-code:

A pattern of holes in a wall, for less weight/material. Could be round holes or some geometric pattern.
Empty enclosed space, with some grid-structure for stability. Again, for saving weight/material (and time during the printing).

Are there any libraries for these things?

I'm not aware of libraries that do that for you (but you can create your own, see end of the answer), but creating a relieve hole pattern is not that difficult or tedious using iterator functions (e.i. the for loop). Note that it may not be a good idea to make enclosed holes inside your object, see the edit section at the bottom of the answer.

Small OpenSCAD test script:

 tol=0.2;

 difference(){
   cube([100,100,10]);
   for (x=[10:20:90]){
     for (y=[10:20:90]){
       translate([x,y,-tol/2]){
         cylinder(r=9,h=10+tol,$fn=180);
       }
     }
   }
 }

This can be used for both parts of your question, but in case the pattern needs to be inside an object you need to lower the value of h in the subtracting cylinder and raise/translate it (you could use the center=true in the cylinder function as a parameter and raise the center to the middle of your object translate([x,y,objectThickness/2])). You could make a module of the recurring pattern yourself to create your library.

note: Replace cylinder with cube or any other geometrical solid or (2D) pattern (use linear_extrude) to subtract from your part.

EDIT:

Note that it is not always wise to create your own spacing/grid structure enclosed in the model. Please read the accepted answer of this question. This answer explains that slicer applications work best with true solids!


Anet A8 stock replacement fuse between motherboard and PSU My inline fuse burned and I don't know how many ampere the new fuse should have.

Couple things to note.
First one is that as @Paulster2 mentioned, the fuse itself should have its rating printed on it.

Second one is that if your fuse blew, there's a reason for that, and you really should try to figure out what that reason is before you start putting fuses back in. The Anet A8 isn't exactly what I'd call a high-quality kit, so there's a chance you've got a blown FET or something somewhere that has shorted closed and is just drawing power nonstop. You should start by getting a multimeter and checking the continuity of the power traces for your hotend and bed, without power in the system. You can do some basic safety checks that way.

Once you've gotten that done, if you're referring to a 12 V feed line, that should be somewhere in the ballpark of 20 A fuse. If it's a fuse on the mains power, it'll be like 1 A or 2 A depending on whether you're on 240 V or 120 V mains (respectively).


3D printing bed size and selecting models I was thinking of getting the MonoPrice Mini 3D v2 printer.   I know the bed is kind of small.

How would I know what I could print from Thingiverse?  They don't really state what the bed size should be.

Does the software fix this for you?  Do you scale it?

Yes, objects in thingiverse usually doesn't include their size and this can require extra effort to obtain.
There are several options to scale objects to fit your printer.  You can often do that in the slicer or using a separate program like meshmixer.
The bed size is not the only (or maybe even primary) limitation you will need to consider when printing an object.  You also need to think of your max height, nozzle size and for your choice of material your will need to consider things like you max extruder and bed temperatures (or even have a heated bed), nozzle type, etc.
You should be able to print just about anything on thingiverse; but, the limitations of your printer will affect HOW you will have to print it and whether you will be happy with the final product.

I have heard of plenty of people the have smaller printers and it was the right place for them to start.  Having a smaller printer that performs well for you will be a much better experience than a larger printer that performs poorly.

Whether the Monoprice Mini 3D v2 printer is the best printer is something only you can decide.  Read and watch the reviews, they can be a great source of "perspective". I know we all have limited budgets and there are certainly way more things you can print with a printer than you can without one.


How do I use MEGA pin number designations rather than RAMPS pin numbers in marlin I am designing my own shield for the MEGA2650 that I will use to control my printer.

When defining pins in the marlin firmware, the pin numbers are the pin numbers of the RAMPS shield and not the Arduino MEGA itself.

How can I define pins so that I could write #define HEATER1PIN 5 and it will make heater1pin be on Arduino MEGA's pin 5 and NOT RAMPS's pin 5

The pin mapping that Marlin uses is defined in the file fastio_1280.h:

/**
 * Pin mapping for the 1280 and 2560
 *
 *   1280     22 23 24 25 26 27 28 29 53 52 51 50 10 11 12 13 37 36 35 34 33 32 31 30 21 20 19 18 81 82 83 38 00 01 78 05 02 03 79 80 54 55 56 57 58 59 60 61 41 40 39 71 70 04 17 16 84 06 07 08 09 85 15 14 72 73 75 76 77 74 62 63 64 65 66 67 68 69 49 48 47 46 45 44 43 42
 *   Port     A0 A1 A2 A3 A4 A5 A6 A7 B0 B1 B2 B3 B4 B5 B6 B7 C0 C1 C2 C3 C4 C5 C6 C7 D0 D1 D2 D3 D4 D5 D6 D7 E0 E1 E2 E3 E4 E5 E6 E7 F0 F1 F2 F3 F4 F5 F6 F7 G0 G1 G2 G3 G4 G5 H0 H1 H2 H3 H4 H5 H6 H7 J0 J1 J2 J3 J4 J5 J6 J7 K0 K1 K2 K3 K4 K5 K6 K7 L0 L1 L2 L3 L4 L5 L6 L7
 *   Marlin   00 01 02 03 04 05 06 07 08 09 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85
*/

Confusingly, the line labeled "1280" refers to the pin numbers as used by Marlin. The line labeled with "port" gives the corresponding port/pin combination as it applies to the AtMega2560 chip itself. To translate between the port numbers given above, and the Arduino Mega pin numbers, you can use the following pinout diagram:

Licensed under CC-BY-SA, www.bq.com

For instance, according to the pin mapping in fastio_1280.h, Marlin pin 34 is "port" C3. This corresponds to PC3 in the pinout diagram, which is Arduino Mega A11. Conversely, if we want to find out what PWM pin 9 is in Marlin, we can look at the diagram to find out it corresponds to PH6, which is Marlin pin 09.

If you want to change this numbering, then unfortunately, you have to make quite a few modifications to fastio_1280.h. For instance, the "reason" pin 5 corresponds to the pin it does, is the following set of definitions:

#define DIO5_PIN    PINE3
#define DIO5_RPORT  PINE
#define DIO5_WPORT  PORTE
#define DIO5_DDR    DDRE
#define DIO5_PWM    &OCR3AL

If you wanted to point pin 5 towards another pin, you'd need to change all of these lines to point to the correct registers and pin numbers.


Vertical 5 mm diameter hole comes out fine, but diagonal 3 mm holes keep collapsing I am trying to 3D print an object from Shapeways. Confidentiality prevents me from sharing the actual STL files publicly, but what I can say is that it's a shape about 2 cm tall x 4 cm wide x 4 cm deep, and where the design specifies a vertical hole 5 mm in diameter, the hole comes out fine, but where the design specifies multiple holes 3 mm in diameter, passing diagonally through the shape (at a 45° angle with the ground), the holes seem to collapse (i.e. I can't see through them, and if I push a straightened paper clip through the hole, it's blocked). This has happened repeatedly (e.g. Shapeways offered to re-print some shapes for free when they came out defective, but this happened the second time too).
I am new to 3D printing and trying to figure out:

Is the hole more likely to "collapse" if it's diagonal rather than straight up and down? Is this because when the shape is being 3D printed, it's oriented exactly as shown in the design, and so before the 3D printing materials have fully solidified, the holes are more likely to be collapsed by gravity? Or does it have more to do with the diameter of the holes, and if I made the shape with 5 mm diagonal holes, they might not collapse?

The material I'm picking from Shapeways's options is "Black Natural Versatile Plastic". Are there other materials that are less likely to have this problem?

A member of the public on Stack Exchange's forum gave me the answer:
"The problem is not the hole 'collapsing' in and of itself. The problem is the material.
Versatile Plastic is a layered powder fused together with a laser in multiple layers, so the unused power has to come out from the various holes in the model once printing is completed. However, these layers are also very thin and compact. Therefore, if you make a small enough hole, the powder simply won't flow through it and it becomes stuck. Due to the small dimensions you listed (of said hole) it's gonna be difficult to free it due to the sheer compressing forces involved. When working with such fine details Versatile Plastic is not the most indicated material.
The only correction you can make to rectify the problem is changing material. Fine Detail Plastic would be a good choice for a new test, although it is not cheap compared to Versatile, is certainly cheaper than metals.
Fine Detail Plastic should provide you with a good result if you feel like trying it out."
ShapeWays technical support told me basically the same thing, and added that ordering the shape in black might also exacerbate the problem:
He said that when a model has holes in it, a human actually pokes the holes to get residual material out if possible.  Then he adds: "The last issue would be that Black indeed causes additional issues. If the production team isn't able to clean the model properly, or didn't do their work right, this could become and issue when we dye your model. All Versatile Plastic is printed in White, when selecting a colored finish such as black, we dye the model using a bath of regular RIT DYE. If the hole still has trapped powder, the bath will make the loose powder wet and make it become sticky, in combination with the dye this causes it to become chunky on the inside."
TL;DR: I can try to fix it by using Fine Detail Plastic, or I could try ordering in white and then painting it black myself to avoid gunking up the holes (the insides of the holes don't need to be painted black).


Improving triangulation on AutoCAD-generated stl files In regards to a part that I'm having printed remotely (by two processes:- stereolithography and laser sintering), I've been advised by the 3d printing company that 'the triangulation of the file is rather rough'.

In this particular instance, it probably doesn't matter, but for the future, are there any tips to improving 'triangulation' when generating forms in AutoCAD?

Note, AutoCAD's FACETRES variable is set to 10.

The phrase "triangulation of the file is rather rough" is somewhat vague, but one can interpret it to mean that the surface is what is considered "low poly" in the 3D modeling world.

From Thingiverse, this low poly fox shows an intentionally reduced poly surface. I'm not suggesting that your models appear this distorted, but it may give a hint to what the service is referencing.

Consider to load your model into a program such as Meshmixer, which will show you the triangles in 'W'ireframe mode. If there are few triangles over a surface, you can get the aforementioned effect.

Meshmixer also allows you to increase the mesh count, possibly improving the surface and satisfying the requirements of the printing service.


Getting started with converted STL to DXF I converted the STL file through an online converter https://www.cadforum.cz/catalog_en/stl2dwg.asp

(I work in the program autocad 2017)
Now I open the resulting DXF and I don’t know how to work with it. How do I merge polygons into a whole model?

I figured it out. Need to go: Network -> conversion to surface

Then we get a surface that is already easy to work with.


Can I replace the cooling fan blade for the hot end on creality ender 3? I broke one of the blades of the fan and that's making the x-box vibrate. Other than that it works fine and I can still print at a very low flow rate and a lot of noise. Will replacing the blades, not the whole fan work?

Found this and how to replace on thingyverse:

https://www.thingiverse.com/thing:186979

It will work, but likely with reduced performances: designing blades is not an easy task and the ones you can print will not be as good as the ones designed for that specific fan.

Overall, do it for fun before you replace the fan anyway.

IF your fan has symmetrical blades (unlikely), another option is to break the opposite blade to balance the fan.


How to wire an LJ18A3-8-Z/BX sensor with an optocoupler to a stock Ender 3? I have this optocoupler.

and this sensor.

I want to wire them together and use them for auto bed leveling. Note, stock Ender 3 board (Creality v1) has 2 pins for its endstop, not 3, so this:

won't work
However, I found this diagram:

My optocoupler is rated for 12 V so I definitely wont attach 24 V to it. However, everything else seems good. So I could only replace the 24 V to 12 V and it would work?

Both diagrams are exactly the same, the difference is the +5 V that is not connected on the bottom diagram (displayed in white, labelled "not used"), but since your endstops do not have a +5 V pin in the socket (only ground, GND, and signal, SIG or S) you don't need to attach it. You should source the +5 V from elsewhere from your board. As the left and right side of the module are separated circuits, you need to power the board with +5 V.
Read this answer for applying 24 V.


Flashforge Dreamer not able to read Cura created G-code file I'm using a second hand Flashforge Dreamer with ABS filament and Cura as slicer.

The Flashforge Dreamer cannot read the printing (G-code) file Cura creates, I think due to not knowing what the printer firmware is? I want to use some of the Cura features that the FlashPrint software does not have.

What firmware does Flashforge Dreamer use? I think I have to input to cura the machine details (name not listed on list of printers in the drop down menu) and even Google could not tell me, nor the Flashforge website.

Cura has a built-in list of printer specs, but no Flashforge, so even the name of a clone type of the Flashforge using the same type of firmware would help.

For the Flashforge Creator model an alternative firmware is available; Sailfish. However, Sailfish is not available for the Flashforge Dreamer. As a matter of fact, no alternative firmware is available for the Dreamer as a consequence of the Flashforge Dreamer being closed hardware and closed source.

Not knowing the flavor af firmware (as it is closed source and could well be using a custom firmware build) using Cura to slice models for G-code files gives no guarantee for successful printing.

To be able to use Cura you would have to switch the current board from the Flashforge Dreamer and replace it with a board that accepts Marlin Firmware. Note that there is no default configuration for this pronter available so this requires a little work from you to go through the Marlin configuration file and adjust various constants to make your printer work. [edit: As pointed out below in the comments, in the process you will lose some of the maximum speed the Dreamer is capable of!]

Another option is to buy a license of e.g. Simplify3D (note that I have no affiliation with Simplfy3D!) as they claim to support this printer. There could be other software suites that support your printer.


Filament lifts from the hot bed while printing I have a Tevo Tarantula 3D printer.

I'm trying to print a calibration cube.

The slicer is Cura and is set for a 1.75 mm filament extruded by a nozzle of 0.4 mm, with a heat bed temperature of 60°C and extruder 200°C.

As seen in the image I stopped the printer after a minute, when I noticed that the filament wasn't sticking to the hotbed.

I've also made other tests, but the result is the same - the upper right part of the print lifts and touches the moving nozzle.

How could I resolve this? Any advice?

Check the following:

Is the print bed clean? On glass, you can use a few squirts of window cleaner.
Is the print bed actually reaching the correct temperature?
Have you manually calibrated the printer (at both the center and the edges), such that you can just about get a sheet of paper between the print bed and the hotend nozzle, at z = 0? This last check ensures that the first printed layer of extruded filament is actually touching and "presses on" to the print bed. See the video #18:Calibration for a great explanation on the use of the paper. Whilst this video is for a Delta printer, it clearly demonstrates the height that the zeroed print head should be at, and how to check using a sheet paper.
Maybe the filament, for the first few layers, should be heated at a high temperature, than the rest of the print, to ensure adhesion.

If all of the above are checked and OK, then (as electrophile points out in their answer) try making the print head more grippy. This can be achieved by simply adding a thin coating to the glass with one of the following:

Wiping the glass with a glue stick or wood glue
Using hairspray

Both use PVA as an adhesive/stiffener.

Or by adding an additional print surface, such as:

Using blue painters tape
Using PEI tape
Using Kapton tape
Using BuildTak

If adding tape, then the printer may require a small re-calibration, due to the thickness of the tape adding a few microns to the print bed height. This can be done in the firmware.


Optimal ratio of fresh to used nylon powder I am operating a laser sintering machine, using polyamide 2200 powder (with a grain size of approximately 50 micrometers). During a print, a lot of powder goes unsintered and can theoretically be reused. However, using purely recycled powder degrades print quality to an unacceptable level.

Mixing a little used powder into a larger amount of fresh powder seems to work well though. What is the greatest ratio of used to fresh powder that still gives good results, and is there anything I can do (pre- postprocessing) to allow more powder to be reused?

I currently use the 60/40 recycling mix ratio and find that it works very well.  I do however wonder if there is an even more effective ratio in order to recycle used powder.  I currently discard all "cake" powder (powder remaining in the build piston) and am only "recycling" the push off powder.  I found this paper but it's unclear if they are reusing just the push off or both push off and cake.  Any further opinions/ideas would be greatly appreciated.

http://www.internationaljournalssrg.org/IJME/2015/Volume2-Issue7/IJME-V2I7P106.pdf


Labists ET4 printer nozzle hits bed after automatic levelling I use Slic3r to create G-codes for my Labists ET4 printer. Usually, no problem.
Now, as soon as I tried to start a print, the nozzle head went down as usual, but this time it went a bit lower than 0 and the machine made angry noises for less than a second.
It went back up again and heated the bed and the nozzle, only to go back down too strongly with angry noises again. Even left a little pokey hole on the bed.
I got scared and turned the machine's switch off and manually raised the Z axis with ease.
Never had this problem before and now I'm afraid to turn on my machine.
I've had the following setup for G-codes prior to today's incident and it had worked just fine:
G28 ; Home extruder
G1 Z15 F[travel_speed]
M106 S[max_fan_speed]; Turn on fan
G90 ; Absolute positioning
M82 ; Extruder in absolute mode
; Activate all used extruder
M104 T0 S[first_layer_temperature]
M190 S[bed_temperature]
G92 E0 ; Reset extruder position
; Wait for all used extruders to reach temperature
M109 T0 S[first_layer_temperature]

After this, I did try the auto levelling, however it still tried to plow into the bed, albeit not as angrily.
Here's other things to potentially consider:

I haven't used the machine 10 days.
It's been chilly in the room where the machine is.

So here's my questions:

"What could cause a 3D printer to have an incorrect impression of Z-axis=0 even in absolute position mode?"
"What can I do to fix it?"

Dirt. It was dirt. Most likely.

Apparently the machine establishes bed level with a sensor, and I might be wrong, but I think the ET4 monitors capacitance as a means to notice how far the nozzle is from the bed.
After all else failed I looked at the nozzle closely and noticed that the whole thing looked fuzzy. Looks like soot (from where though!?) had settled on the machine's sensitive components and de facto blind-folded its sensor.
A wipe and a levelling later, all was back to normal. Yay!


Problem with first and last layers I bought Ender-5 and if I print sample model in bundle SD, it’s just perfect.

But when I tested basic cube with raft, its base and top is just ugly. Even thought its 4 sides are perfect.

Ultimaker Cura 4.2.1
Bed temperature 45 °C
Extruder temperature 200 °C

Which setting(s) should I check futher?

You may want to ensure that your filament diameter is correctly set in your printer's CURA profile, and that your hot end is at the correct temperature for the material you are using. Additionally, you should not need a raft to print the cube, and should be able to do without a raft or brim.


Empty space in model is getting filled I drew a fairly simple model in Google SketchUp. I exported it as an STL. I imported it into Cura and exported as gcode. Then I printed the model.

All of the bottom layers of the model cover the entire space instead of leaving the two open gaps that should exist. I don't know why it's happening. Do I have some weird setting in Cura?

The section that is filled, but shouldn't be, isn't a raft. I printed without a raft because my model goes to the max extent that my printer can print and I don't have room for a raft around the edges.

Here is what it looks like in SketchUp:

Here is what it looks like in Cura. The two empty areas are shaded darker than the other empty areas of the build plate. Is that an indication of my problem?

Here is what was printed. The empty areas are solid and filled in as if the center piece extended to the inner edges of that area. (The jacked up corners are due to the model warping a bit and no longer being in the right position for subsequent layers.)

Here is a video of the layers according to Cura, and Cura clearly knows the gaps should be there:

https://youtu.be/r0a9gGFerHI

I suspect, as I am wont to do, that your problem lies in the STL created by SketchUp. It's an unfortunate aspect of that program that it creates non-manifold models which creates troubles such as this.

Consider to load your STL file into a program suitable for showing flaws (and repairing them) to determine where the failure points lie. I'm fond of Meshmixer, but there are many others such as Netfabb with which I am less familiar.

If you don't want to check your STL file, attach it to your post and I'll take a shot at it.

You would also want to consider to learn a new program if you intend to perform such 3D modeling. Fusion 360 has a popular following. I'm a fan of OpenScad, but use Fusion 360, Meshmixer, Blender (only a tiny amount) and anything else I can utilize for model repair, creation and editing. Build a large repetoire of different programs and get the best of all worlds.

SketchUp has a strong following primarily because it's rather easy to use. The same can be said of a few other programs, but SketchUp really generates trouble when it comes to 3D models.

TinkerCAD is very much like SketchUp and will give you better final results. OnShape is another popular modeling program, but I have zero exposure to that one.

It's not out of the question that there's a bug in Cura that's causing this problem. You are not limited to one slicer program, and you can check the results of another slicer such as Slic3r, Craftware or others.


Does Cura have an algorithm for any infill percentage or does it just have specific patterns? Looking in the Cura interface, I can set any whole number 0-100 for the infill percentage. Does Cura have an algorithm to calculate a pattern for any of those possible values, or does it have a few patterns where it selects the closest one?

I fear I'm going to deny your question.  The infil percentage and the infil pattern are two orthogonal properties, both of which contribute to the strength, density, mass, and print time of an object.   Since there's no way for an algo to "know" what your desired outcome is, this can't be done.

Note - I used 'orthogonal' in the Hilbert sense, meaning neither property is a function of the other.


Is Tetrahydrofuran viable for dissolving PLA and sticking PLA objects together? According to Wikipedia, Tetrahydrofuran dissolves PLA. It also apparently dissolves PET.

  THF is considered a relatively nontoxic solvent, with the median lethal dose (LD50) comparable to that for acetone.

Wikipedia further states that it's not particularly dangerous provided you keep it away from air circulation, so that it does not form peroxides.

  One danger posed by THF follows from its tendency to form highly explosive peroxides on storage in air.

So well, this seems acceptable compared to other possible solvents which are all ridiculously dangerous. The question at hand is now of practical nature:

Is Tetrahudrofuran actually viable replacement for acetone, which only works with ABS?

I am asking because the fact that it does dissolve PLA does not really at all mean that it will work well. It could damage PLA structure, be more toxic than wikipedia says or not dry well.

According to Shuichi Sato, Daiki Gondo, Takayuki Wada, Shinji Kanehashi & Kazukiyo Nagai: Effects of various liquid organic solvents on solvent‐induced crystallization of amorphous poly(lactic acid) film in Journal of Applied Polymer Science, Volume 129 Issue 3 (2013), p1607-1617source, Tetrahydrofuran is classified as a solvent for PLA. The specific entry on page 1608:
Group  Solvent          Solvent type    dd   dp   dh   dt   Result
Ether  Tetrahydrofuran  Polar aprotic  16.8  5.7  8   19.4  soluble

The values dd dp dh and dt are explained on page 1607:

The effects of 60 liquid organic solvents on PLA are systematically
investigated using the Hansen solubility parameter (HSP). The HSP
is one of the digitizing methods for analyzing the interaction
between polymer materials and organic solvents. In HSP analysis,
all solvents have three parameters: energy from dispersion bonds
between molecules (dd), dipolar intermolecular force between molecules
(dp), and the hydrogen bonds between molecules (dh). All solvents
were characterized by a point in a three-dimensional structure
at which dd, dp, and dh are plotted on three mutually perpendicular
axes. Generally, if the HSP values of the various organic solvents
are near that of the given polymer, the solvent is considered compatible
with the polymer material.

The factor dt is the total Hansen solubility parameter - the bigger this is, the better it is a solvent.
19.4 is a rather good solvent but extremely explosive: in air 20000 ppm (2%) are explosive and thus the allowable concentration in an area is 2000 ppmsource
Alternatives
A similar potent solvent would be Benzene (dt = 18.6) which more easily available and less explosive, but more deadly (10000-20000 ppm fumes) and has an allowable concentration of 500 ppmsource
Ethyl-acetate is also a solvent (dt = 18.2) and more available. It is explosive at an equal concentration as Tetrahydrofuransource, but it has just about half of its vapor pressure (73 mmHgsource  vs. 132 mmHgsource), so can be stored more safely, and is less aggressive on the body. It is sometimes used to Smooth PLA via vapor chambersource, and only comes at a price tag of ca. 90 €/l for the pure stuff and also is used in some nail polish removers, put into a safe mix.
Acetone is classified as a better solvent (dt = 20.1), and it is known to act as a glue and to soften PLA with some exposure time, but from experience, it can't smooth it. It is available most easy (nail polish remover and in the home depot), and is the least deadly option.
Propylene-1,2-carbonate is classed as solvent and a far better at it with dt = 27.2. It has been used as an alternative to Ethyl-Acetatesource and its MSDS is rather gentlesource. It comes at a price tag of 130 €/l for the chemical-grade liquid.
Conclusion
Tetrahydrofuran is not a viable replacement due to its explosive properties. It is not an improvement above Benzene, which at least can be stored safely.
Using Acetone as a benchmark, Tetrahydrofuran should not smooth the surface in a vapor chamber, as it is a worse solvent than Acetone. It should also take longer to soften and dissolve objects than Acetone, but a heated bath or coating the surface with it could help to generate the needed exposure times.
However, its comparable ethyl-acetate has been claimed to be used as a cleaning, vapor smoothing, and brush on surface smoothing agent successfully and can be used better by helping the solubility via heating, which can be done much safer with ethyl-acetate than THF. In a proper chemical mix, its storage problem can be solved too.
A better alternative is propylene-1,2-carbonate, which is a better solvent, and much less dangerous.
tl;dr: No, Tetrahydrofuran is not able to dissolve PLA in a reasonable time1 without heat activation and it has worse characteristics than Acetone. It could arguably be used to weld parts, but Dichloromethane would be more effective.

1 - Sato, Gondo et al. in the aforementioned paper: Solubility tests were performed for 24 h at 35+-1 °C. which means we have a prolonged exposure of a thin film to a huge amount of solvent. how thin a film? Very thin: The PLA films
were prepared by casting 2 wt % dichloromethane solution onto a
flat-bottomed glass Petri dish in a glass bell-type vessel and by drying
under atmospheric pressure at room temperature. Each solvent
was allowed to evaporate for 48 h. The dried PLA films were then
thermally treated under a vacuum for 48 h at 70 °C to eliminate
the residual solvent and to obtain amorphous PLA films. Afterwards,
the thermally treated PLA films were cooled at room temperature
under atmospheric pressure.


After print failure cant extrude PLA I had a failed print lastnight and a glob of pla surrounded the hotend. After heating it up and removing the glob the extruder does not release any significant material. I checked with OctoPrint and the extruder stepper does push filament without the hot end on.
After fully heating the hot end I was able to remove the nozzle.
I then pushed the previously melted PLA out of the tube and heater. It was discolored in the heater. I then tried to put the nozzle back on and pull the old PLA out of the nozzle but no success there.
Should the nozzle be left in acetone for a few days  before trying again or how should this be dealt with. The nozzle appears to be blocked.

If the hotend is okay, consider yourself lucky and consider the nozzle a loss. Aside from specialty items like ruby tip ones, nozzles are a consumable anyway. Even if you can clean it out well enough to get it working again, it's unlikely to extrude as well as a new clean nozzle. Acetone is probably not going to help; PLA does not dissolve in acetone, and while the pigments/additives might be affected by it enough to weaken and deform PLA in a way that could get it to detach, what's clogging your nozzle is likely burnt/carbonized PLA that's unlikely to be removable by anything that won't also destroy the brass.
If you don't already have replacements on hand, get yourself a pack of 10-20 for $10 or so and be ready to replace when needed. You can also go for a mixed-size pack if you want to try printing fine details with a smaller (0.1-0.3 mm) nozzle or super-fast but rough with a large (0.8-1.0 mm) nozzle.


What to do if filament spool won't fit in 3D printer My sample filament has just ran out. Luckilly, I've already bought more filament. The only problem I have is that the spool for the new filament won't fit inside my 3D printer. The filament itself works with my printer; it's just the spool that is the problem. Does anyone have any solutions for what to do if a filament spool won't fit in your 3D printer? For reference, I have the FlashForge Adventurer 3.

A spool does not need to be inside a printer. Or on. Or even next to.
My Ender 3 pulls his filament in from the rack above it, my TronXY X1 pulls it from about 80 cm to the left of it, where it hangs from a shelf.
When making a solution that pulls in filament from afar, it is necessary to make sure the path is unobstructed and works for the whole movement range of the printer without getting bent sharply, as that can snap or kink the filament.
In the case of the small printer you have, leave open or remove the door to the filament chamber and make sure to place the spool holder so it drags in the filament straight. There are even spool holders designed specifically for this printer.
There are many designs of spool holders out there, many of them free and with minimal assembly.
RE-spooling
Some printers, especially ones that only take marked rolls, might need their spool cores re-filled. In that case, you need to take utmost care: re-filling a spool needs to be without any twist to the filament or you risk entangling, and you need to make sure to not kink or bend the filament in doing so, or risk breaking at those spots.
Due to the risks involved, this should be avoided whenever possible!


Is this re-Arm controller actually 24 V capable? I would like to make a 24 V (3D printer board and shield) setup, as opposed to the usual 12 V, and to do so I had been considering using the Taurino Power board, or the clone Eruduino. However, I just found this board:

The specifications state a DC input of up to 36 V:

Does anyone know whether that really means it can handle 24 V in the same manner as the Taurino/Eruduino? If so, then that looks like a double win: not only 24 V support, but also a faster processor. Anyone have experience with this board?

I was thinking of using with a RAMPS1.6 Plus (maybe), or just a regular RAMPS 1.4 (hacked to support 24 V). I'm just shopping about, and I thought that if I was going to spend £14 on an Eruduino, then I just as well spend that money on something better.

It does work with Marlin apparently, as some of the customer reviews would suggest, but none of the reviews that I could find referred to a 24 V setup (heated bed etc.), hence my question.

Given that the capacitor near the input is quite clearly marked 35 V, a 36 V rating seems questionable.

The (buck) regulator used on the (genuine version of the) board is the AOZ1282CI which supports up to 36 V input. This is probably where they got the 36 V rating from, but obviously the 35 V-rated capacitors drop the input voltage down below this.

Schematics for the board are available on the RepRap wiki and show that the input voltage only feeds into the regulator. I see no reason why this board couldn't handle 24 V input, as this is well within the rating of both the regulator and the capacitors.


Is there any opensource software that controls the RAMPS RepRap board directly from the computer? I'd like to find an opensource software that communicates directly with the RAMPS board (or any other 3D printer driver) without using the arduino...

It doesn't matter if it runs on Windows or linux as long as it's opensource. Also, I'm not worried about how this communication is done (USB, serial port, parallel port)...

Has anyone ever heard about projects like this?

No, there exists no software like that. You can't communicate with a RAMPs board because a RAMPs board has no logic built-in; it's just a dumb breakout board that connects the Arduino Mega to your printer's components (such as stepper drivers, MOSFETs for controlling heaters, endstops,...).

If you wanted to connect a RAMPs board "directly" to your computer, you'd need a way for your computer to generate the pulses that the Arduino normally generates. You could potentially use a parallel port for this but you'd need many more outputs than a single parallel port can provide and you'd need to find a way to do the analog to digital conversion needed for the thermistors.

It's just not very feasible (considering how few computers have parallel ports nowadays).


When is kapton tape useful as a bed adhesive? I've long since been aware that some people swear by Kapton tape as a bed adhesive, with MatterHackers claiming that Kapton tape is the recommended bed adhesive for ABS.

What makes Kapton tape so useful for printing with ABS? Is it also useful for printing with other materials?

I tested Kapton tape for PLA, ABS, PETG and XT. I know it works for other materials as well. What you need to keep in mind is that many materials only stick to Kapton tape well if you use a heated bed.

The advantage of Kapton tape in comparison to other materials is its heat endurance and mechanical stability. It protects the glass underneath, while you remove the print from the surface. Some filaments stick so well to glass that you may break chunks out of it.

The major disadvantage of Kapton tape is the time to apply the tape to the print surface and its very smooth surface pattern which seems odd in comparison to the rest of the print.


Simplify3D with error in preview? I am trying to print a belt but when I preview it, the model doesn't fully render

It isn't rendering the full model correctly. The model is rendering halfway but isn't fully which is why you can still see the infill when the slider is at max which isn't normal.

This is what it should look like:

I have a 0.4 nozzle and those with a 0.6 have been able to print this. What is going on?

First I thought that the model was improperly modeled due inverted faces or any missing line to close that faces but, I rendered the same STL to be printed 0.4 nozzle with height 0.2mm and looks pretty well.

Then I suspected that you were trying to print with 0.4 nozzle at 0.6 layers, which this is totally wrong but, I decided to set the 3D simplify and do the test. The program just show a warning about first layer height adhesion, the click OK and the part is rendered correctly.

However the recommended settings for a 0.4 nozzle should be less than 80% diameter = 0.32mm as maximum to get a proper bonding.

So, I think that you need to download the part and render it again. The time to process this render under XP with an small PC last for 5 minutes. So on bigger PC's will be faster.

Here is the link where I downloaded the "belt Komplett 805"


E3D V6 nozzle vs MK8 nozzle, first layer adhesion Does anyone notice that when they upgrade from an MK8Makerbot(?) to a E3D V6 hotend that when using the same settings and bed-leveling/z-distance-setting procedures, that the filament is much more likely to be pulled up and bunch up around the nozzle while printing the first layer?

It occurs mostly when printing small details, such as 3 mm bolt holes, and not so much when laying down long lines.

Is this due to the shape of the nozzle, which on the V6 is much more flat when compared to the MK8 which is more sharp, or is it due to something else that can be easily fixed?

When filament curls up this generally means that there is some sort of obstruction or burned material in the nozzle causing uneven flow. You can use the Atomic Method from this answer.

Being a new nozzle, I would expect that this is not the case, so that it should just drop out of the nozzle and not curl up. It could be that the nozzle is not perfectly machined and a defect in the geometry is causing this. You could try to replace the nozzle with another nozzle. They are pretty cheap, you should buy a few extra.

As far as why the filament sticks easier to the E3D nozzle when it curls up, is that this nozzle has a (hexagonal) flange that sticks out, while the other nozzle does not have such a flange. If it curls up, it has a larger probability to hit the flange and stick to the outside of the nozzle than a nozzle that has no such flange.


Standard Settings for AnyCubic Printers? Does anyone know where I can find a list of recommended settings for different types of resin / print objects for Anycubic printers?
I realize that some of the details will need to be tweaked on a case-by-case basis, but having some general starter information (exposure times for first 6 lines + rest of the print, step settings based on type of print, etc) would certainly be better than starting "cold".
It seems like this information should be gathered somewhere, either for ALL printers, or separate ones for each type of printer.

Times are not dependant on the printer but the resin. Please look at the resin's label, which should have recommended settings.


Where is the "slice" button in Cura? I'm relatively new to Cura, having just installed it a few weeks ago.  I have 3.0.3 and I'm running on Windows 7 64 bit.  I noticed the auto slicing setting while poking around the settings.  Auto slice almost always works.

A couple times now, Cura won't auto slice. I can't seem to find the slice button.  How do I manually slice?  I found an article on how to disable auto slicing, but it doesn't show how to manually slice.

Where the button "save to file" is is greyed out and just says "Print with Octoprint".

Closing Cura and re-opening it will fix the issue.

If auto-slicing is disabled, the button in the bottom-right corner of the window toggles between "Prepare" and "Save to File" depending on whether the model needs to be re-sliced or not. While slicing is in progress, it changes to "Cancel".

If auto-slicing is enabled, the button always reads "Save to File", and is greyed-out when slicing is being performed (it does not change to "Cancel").


Ender 3 X-axis values are not correct So I just got the Ender 3 and have been trying to print out a part. However, I noticed the printer is trying to print the part, which should be centered in the bed, on the left side.

I performed the auto home, leveling procedures, prior to execution, but it still wants to print it on the left side.

I checked the values it thinks it has for X, but they are about 60 mm to high (i.e. from the control/move axis menu, I move it towards the zero position and when it touches the switch, it still thinks its around 65-70 mm in the positive direction).

I have tried the good old power cycle, but each time it seems to get worse printing closer and closer to the edge. I am sure that I must have fudged something up. Anyone know how to fix the mismatched position?

Thanks for any advice!

So the issues with the digital display values, was caused by the X-axis binding up and not advancing. I had to move the axis via the control panel in the positive direction and noticed once it got about half-way out, it wouldn't advance for like two or more steps.

On the control panel, it said I was 235 mm out from the home position, but in reality I was more around the midway point. When I would move it back to the home position the read-out still displayed that I was offset from the home position in the positive direction.

To fix it I tore it down and reconstructed it (made sure everything was plumb and level), I also flipped the belt in the opposite direction (teeth down, so that the stepper pulley grips the belt teeth).


Measuring Z positioning accuracy I'm looking for a methodology to easily measure/evaluate Z positioning accuracy, using equipment on hand or easily obtainable such as a high-precision digital caliper. In particular I want to be able to evaluate whether steps (actual motor steps, or some other chosen unit of increment) are uniformly the nominal step height, or whether some are larger than others, and if so whether the irregularity is reproducible. Has anyone worked out a way to attach a caliper or equivalent measurement device sufficiently rigidly to both a fixed point and a moving-in-Z point (e.g. the bed and the gantry on a typical cartesian machine) that the magnitude of individual steps can be read off? Or maybe a high precision laser range finder/interferometer solution is more appropriate, but I'm not sure about cost/availability.
I ask this in the context of recurring concerns about a common overconstained Z axis design (Ender 3 and nearly everything else with V rollers), but this question is intended to be about measuring not mitigations/fixes.
I'd also be interested in opinions on the necessary measurement precision for this measurement to be meaningful. Almost surely errors as small as 5% of the layer height will lead to some visual surface inconsistency, XY dimensional accuracy problems, and weak points for part to break at, which you'd need 10 micro resolution for 0.2 mm layers to see, but I suspect the reality is much worse for lots of printers and even 20 micron resolution or worse might aid in making serious improvements.

In the world of hobbyist milling machines, a DRO accessory is extremely valuable for improving work flow and accuracy of project builds. The Digital Read Out devices run the gamut from affordable to astonishingly expensive and cover one, two and three axis readouts.
For single axis purposes, some hobbyists will simply find a means to attach a digital caliper, as you've suggested, to the machine with appropriately fabricated brackets. That's one option. For a few dollars more, there are off-the-shelf digital read-outs, such as this one from Amazon:

Six, twelve and twenty-four inch travel options are available with the pictured six inch unit priced at US$39.95, a reasonable figure for 0.01 mm accuracy.
One can purchase pricier models with higher resolution if required.
Brackets included with the device may not fit well to your application and may require modification.
Some DRO devices, such as the one installed on my mini-mill, use physical contact (gears) to read the position information, which means friction and loading of your printer. Other models use micro-engraved glass scales and have minimal friction, but will likely be a bit more expensive.


Slic3r top layer issues, small gaps, weird extruder paths When slicing with Slic3r Prusa edition the top layer of most models turns out pretty bad. There are usually small gaps or weird patterns. This does not happen with Ultimaker Cura, it will have a nice smooth top layer. Is there anything settings wise that I can do in Slic3r to get the same quality of top layer as Ultimaker Cura?

To have a very smooth finish on top layer, I usually act on these settings :

in Print Settings :

Layers & Perimeters :
  Horizontal shells : 3 / 3

Infill:
  Infill, Top/bottom fill patterns : Archimedean Chords ;

Speed:
  .for print moves :
   Top solid infill : 20  (mm/s)

Advanced:
  Extrusion width, Top solid infill : 0.2 (mm)

= This gives very slow movement in a circular way, the small extrusion creates an ironing effect, thus very nice finish.

Considering your slicer behavior, have you tried changing number of top shelves & Infill type ?


How do I give 3D-printed parts in PLA a shiny smooth finish? The surfaces of my printed parts using PLA plastic look rough and uneven.

Would changing filament to a better one make any difference?

If not, what kind of methods can I use to achieve a smoother finish for my for 3D-printed objects?

PLA parts can be finished with a coat of epoxy like XTC-3D from Smooth-On. This will smooth out the part and give it a pretty nice shine.

I've also had a fair amount of success sanding prints, giving them a coat of automotive filler primer, and using glossy spray paint.

You can also get great results with an acetone vapor finish if you're willing to switch to ABS. Though that will require a heated bed and can be a bit more finicky to work with than PLA.


What alternatives are there to sanding resin parts with fine details? I have some transparent resin parts printed with a polyjet printer. Where the support contacted the part it has a matte finish. The recommended finishing technique for these parts is to sand them with sandpaper, but the geometry of my part makes that very difficult. What alternatives to sanding do I have, to give these parts a glossy finish?

I'm looking for techniques appropriate to a home or small office environment. A technique that needs special equipment bigger than a desk is probably not going to work for me.

desktop tumbler/brass polisher, rotary rock tumblers are probably a better option than a small sandblasting cabinet. choose your abrasive material from there, a coarse sand is probably not what you want but there are walnut based things and finer grit materials that should be able to get a nice shine. if you would rather do it manually and geometry allows you can try a dremel-type rotary tool with a buffing wheel or similar


Can I replace hotend on Lulzbot Mini 2 with upcoming E3D Hermes? I've seen articles about the Hermes (now rebranded to Hemera) hotend coming soon from E3D, and was wondering if anyone knows if it's possible to replace the stock Aerostruder on Lulzbot Mini 2 with it. The Aero has been giving me some issues and the printer is currently unusable... I've been printing for a few years but am still pretty new to mods so I don't really know what I'm doing there.

Yes, E3D has a guide "LulzBot Taz6 Hemera Upgrade" if you'd like to make your own.
The upgrade requires you to print parts beforehand which are found here; note that:

We recommend printing the Hemera Mount in PETG, and the Fan Duct in ABS/ ASA or another high-temperature material.
Use an infill percentage of 25 % or higher.

The Hemera (the new name for the Hermes) toolheads are also available for purchase, e.g. here.


How can I create PNG image files from STL files? I need to add some simple image renders of STL files to a document.  I currently open the STL files in Preview or one of the slicers and grab a screen shot.

Is there an easier or automatic way to generate PNG images from STL files on a Mac?

If you have OpenSCAD installed, this shell script will generate 100x100 pixel PNG images for each STL file in your current directory.

for i in *.stl; do
  T=__tmp__$i
  b=`basename $i`
  echo import\(\"$i\"\)\; >$T
  /Applications/OpenSCAD.app/Contents/MacOS/OpenSCAD -o $b.png --imgsize=100,100 $T
  rm $T
done

Credit to 0scar for pointing out STL files can be imported into OpenSCAD.

Update: This code does the same, and generates an html file with annotated images of the files rendered.  When I printed a batch of spare parts for my 3D printer I made a hardcopy and stuck it in the box so I could identify the parts later.

n=-1
H=00-catalog.html
echo >$H '
'
echo >>$H '
'
for i in $*; do
  n=`expr $n + 1`
  if test $n = 4; then
      n=0
      echo >>$H '
'
      echo >>$H '
'
  fi
  echo $i
  T=__tmp__$i
  B=`basename $i .stl`
  echo import\(\"$i\"\)\; >$T
  /Applications/OpenSCAD.app//Contents/MacOS/OpenSCAD -o $B.png --imgsize=200,200 $T
  echo >>$H
  echo >>$H '    '$i'
	'

  rm $T
done
echo >>$H '
'
echo >>$H '
'


Printer changing temperature after selecting file I have just got a Monoprice Maker Select 3d printer (which is really just a Wanhao Duplicator i3).

I want to print a model that came on the included SD card (1.gcode) with ABS filament. I first press "Preheat ABS" and wait for the display to show the correct temperatures, 245°C for the extruder and 90°C for the print bed. Then, I mount the SD card and select the file to print.

However, once I do that, the "goal" temperatures change to 195°C for the extruder and 50°C for the print bed, and the temperatures reported by the printer gradually go down as the printer waits for it to match the "goal" temperature. This results in a failed print, with the filament sticking to the extruder in a clump.

What is going on here? I am trying PLA with the same file, and it seems to work fine, although the temperature change still occurs.

The demo files are gcode files generated for use with the sample PLA that comes with the printer. If you want to print it with ABS select the file and set the temperature manually afterwards.


What is this material? In the context of a personal project I would like to reproduce the appearance of a commercial product of which I send you a cropped image.

I would also like to point out that I do not have the object in question, but it would seem that it is made from a polymer.

The product is a case with an embedded electronical card, so heat dissipation is important.

I'm interested by what kind of plastic is really used here. I plan to have the part manufactured by a company, so I think the method used will be SLS

I therefore rely on your expertise in the field of 3D printing to try to identify the material used.

Thanks

Surface finish does not really map to the substrate material, Visually, what you have shown could be glass, ceramic, plastic, epoxy or metal.

The surface finish is a combination of the shaping process, any post processing, and any surface finishing. Most significantly, there are a wide variety of custom paints which are designed to mimic specific surface finishes. This means you could carve an object out of clay, then spray it to give the appearance of being sand-blasted steel (to give a specific example).

The underlying material is mostly irrelevant to the appearance. It will be driven by mechanical/thermal considerations (is this a mock-up, or does it need to have functional wall-thickness), and production volume/cost considerations (is it a one off, or are you making hundreds/millions)?


Orientation of long thin rod on P3Steel v4 I have a derivative of the P3Steel v4, which is not the Irobri design but another version (I'm not entirely sure which), from Poland: Frame Prusa I3 P3Steel v4.0 +RODS.

I have assembled the frame, following this guide, manual_p3steel_xl, only to be left with one part, which is the long thin rod, which has a small hole, only in one end (the hole is marked by the big arrow in the image below):

This part obviously goes into the slots at the bottom of the Z axis arms, as shown by the curved arrows.

However:

Which way around does the part go?
Should the small hole be on the left or the right hand side, when looking at the printer from the front?
Also, what exactly is the hole for? Is it just for a zip tie, and to be used to keep the cables (maybe from the heated bed (power and thermistor)) tidy?

I have looked at a number of other photos and videos for the P3Steel frame, and none of them clarify which way around, or how, the rod should be fitted. The bar is either omitted completely, or the image is not clear enough to show the correct orientation.

The guide does not show this part being used, although it clearly shows the slots for it in the Z axis arms, in a number of the pictures, such as here:

This is half of an answer. I have finally received an answer from my supplier, which says:

  Long thin rod is mounted as in the photo. I do not know what is a
  small hole.

So the small hole is still a mystery.

Here is the photo that was included with the message (which confirms my placement, just not the orientation):

Update

As tjb1 points out in his comment, the hole can be clearly seen on the right hand side of the bar, in the eBay photo:


Water does not flow through 4 mm hole when there is a small amount, how to let water flow through small hole even when there is low pressure? I have a 3D print where there are 5 holes with a diameter of 4 mm in a cup, and I would like liquid to flow through all 5 holes at once while slowly draining the cup (by slowly I mean: just take a few seconds and not drain instantly). Therefore the holes can not be very large.
When I fill water in the cup it drains fine until there is a small amount of water left, and then it just stops with a small layer of water flowing over the holes.
I'm guessing it is due to surface tension and not enough pressure from water above to push the water through...
Is there a hole design that fixes this problem? I don't know what to Google or if this is the right place to ask the question. It just takes too long to guess my way through and print every attempt at the right size or shape of hole (which I have done so far and still got nothing).

What you encounter there is a combination of Adhesion, Cohesion, and Capillary Force.
Cohesion is what holds the water together. Adhesion is the force to retain water against a wall or hanging from a pen's end, it is proportional to the surface wetted. Capillary Force is the resulting effect where water moves up through a thin tube, it is anti-proportional to the diameter and in the opposite direction of the weight (force). Their relation can be shown in this picture, where a droplet hangs on the end of a glass rod, which has a capillary in it:

How to reduce the water sticking in the cup then?

Make the straight part of the bore as short as possible. This can be done by having a thin cup. The shorter the hole, the less surface there is the water can adhere to vertically, and you might overcome capillary force.
Smooth the hole. Maybe print it 3.5 mm and drill it up to your 4 mm diameter. This reduces adhesion.
Smooth the inside surface. Reducing the adhesion to the inside by having less steps.
Chamfer the inside of the holes. This alters the whole geometry and flow setup in the very low water level case, especially when the surface separates into several areas, above each hole. Then the larger volume belonging to each hole on the inner side means there is a little more pressure and you can get out some more water - and it also shortens the distance the hole has to bridge.
make sure there is some slope everywhere inside so that the water will collect in one of the holes.

An example for a (non measured) design which relies heavily on chamfering to guide the water to the already chamfered holes and then keeps the straight section as short as possible could look like this: the central hole has a very wide chamfer, the whole plate directs water to the center and each of the other holes has a chamfer to guide out water.

However, there is a lower limit to where just tweaking the design will workd, which is based on cohesion. Cohesion is what results in surface tension and viscosity. You can only shift those limiting factors by altering the properties of the liquid, for example by adding an agent that lowers the surface tension and viscosity (soap).