Hello Everybody, I’ve been working on a home-made 3D printer:

Hello Everybody,

I’ve been working on a home-made 3D printer: https://plus.google.com/photos/102071847938163365000/albums/6067700630292404945 It’s kind of working but I have 3 major problems that keep me from getting good enough prints out of my printer:

  1. The infill material doesn’t touch the perimeters for some reason. See some examples here: https://plus.google.com/photos/102071847938163365000/albums/6084902384093859425?authkey=CNGeuMv8kd2kuAE It’s not that the motors are losing steps, because on the next layer the perimeter is laid right on the previous layers perimeter, but the infill is again not touching the perimeter. So I guess it’s either slicing, or firmware problem… I can provide you the configuration in Repetier, slicer, and settings in the firmware if necessary.

  2. My motors seem to be losing steps at the middle of my print. See in this video https://www.youtube.com/watch?v=Exdmpl2QQrM&feature=youtu.be It’s happening when you hear the creaking sound… I have no idea why this happens, but it always happens at the same point.

  3. I can’t seem to get the plastic flowing long enough to finish a print. The extruder motor keeps working but the plastic stops extruding after a while. Sometimes it’s after 2-3 layers, other times after 20-30 layers, other times (less often) it finishes the print without problems. But it’s not a clogged nozzle, because if I start a new print after just a few minutes, or if I push the filament manually, the extruder extrudes again without problem or difficulty.

If you have any ideas or suggestions on how to fix these problems, it would be much appreciated. If you need any additional information, please let me know.

E3D-V6 extruder, Minitronics v1.1 board, Repetier + Slic3r software, filament bought from reprapworld, printing speed: 30 mm/s perimeters, 60 mm/s infills.

  1. You have some serious backlash in your motion - check that all pulleys and belts are tight. Maybe try machined pulleys instead of printed ones. Also, like Mark already said, it seems you have a periodic extrusion error. I’d guess the hobbed bolt/gear is not up for the job.
  2. Might be a bad bearing or an overheating stepper driver.

I would add…

Check your voltage, are you getting enough?
Check your extruder gear isn’t getting tight at some point - in fact, do that with all your gears. You may have to file down a high spot -I did, with my first extruder.

One other thing… What kind of linear bearings are you using on your rotating shafts?

I like your printer. Not much else i could add here but, if the stepper always looses steps when the carriage is as a specific spot i would look for binding in the. Again for what was already said, next i would check VREF, also check for over heating drivers. If the driver is over heating it goes into thermal safety and turns off for an instant to cool it slightly.

I agree with what has already been said about the problems shown in your “printing errors” gallery, but I’d also check the PID tuning in your hot end. The hobbed bolt/hobbed pulley being full of crud or in some way damaged is a more likely cause, but checking your PID tuning isn’t a bad idea (especially if you haven’t done so, or haven’t done so since getting everything mounted in its final position).

Thank you all for your feedback. I’ll go through all your suggestions and see if anything helps. You also gave me a few ideas for some additional test that might also narrow down the list of possible causes for these problems.

@Mike_Thornbury I am using Bronze bushes for all the sliding/rotaring parts. http://medias.schaeffler.com/medias/en!hp.ec.br.pr/EGB…-E40*EGB0812-E40

And they are moving freely? Is it possible they are overheating and binding?

I lubricated thew with some machine oil and they are moving without any problem. I’m pretty confident those are not the problem.

Long-term, I would think that a dry lubricant is a better option. Graphite, PTFE, silicone, etc. I would worry that the oiled rod is just a magnet for dust and vapor

That’s true. I have to wipe it clean quite often. But I think it would even work without the lubricant. Bronze on steel has a quite low coefficient of friction And there are no high forces or speed.

Hi guys,

I’ts been a while since posted the problems with my printer.
Just a quick update:

I changed the pinions and the toothed belt, changed the bronze bushing from the shaft end with ball bearings, added a reduction and reduced the microstepping for the motors and with all these changes I managed to reduce backlash and the motors don’t loose steps any more. So it’s a significant improvement.

I still have some problems with the extruder, but I’m working on that too. (Unfortunately just a little at a time, due to lack of time).

For some videos, check here: