Jump to content
Ultimaker Community of 3D Printing Experts


  • Content Count

  • Joined

  • Last visited

  • Days Won


Everything posted by conny_g

  1. No suggestions needed. The first setup for UM2 is not special in any way. And the camera issue (capture timing out) is not related to Octolapse, it’s something between camera driver and the image capturing (kernel?) framework.
  2. Hi there, I am currently printing a series of lego base plates for my kids and ran into an interesting observation: The "pimples" need to very accurate 4.8mm for the lego bricks to stick well but not too much. It's sensitive to 0,1mm deviation, if they are 4.7xmm the bricks are too loose, if they are > 4.85mm they are too tight (and will rip off the pimples when removing them) or won't fit on at all (approaching 4,9mm). I spent some time to find the sweet spot for two UM2+ with Bondtech extruders and 3D Solex Race block + nozzles in terms of extrusion calibration, temperature and measurements of the .STL so that the base plates are usable in a controllable way. But still - exact same settings, conditions, filament, nozzle etc. - the "left" printer produces them more loose (4,75mm) than the other, the "right" one where the bricks sit very (almost too) tight, with 4,80-4,85mm of pimple diameter. In the last test print of a 2x4 pimple version of the base plate (takes only 10mins to print) I tried to simply tighten the feeder pressure screw of the Bondtech tighter by about one turn. And interestingly the print got better, instead of 4,75mm pimples I received 4,8mm. In one of the tests before I modified the e-Steps from 510steps/mm (calibrated 100mm feed) to 520 (which is +2%) and it also got better and produced 4,8+mm pimples. In another test earlier I found that also +5 C more temperature made the accuracy better, but the print quality worse (slight stringing). So it seems if you want to print measurements like these as exact as possible it's even feeder tension that will influence it. The extrusion obviously varies very quickly by 2+% if you change feeder tension or temperature. I admit it's a rare use case to need 0,1 and less of accuracy, but an interesting learning. Which way would you go, increase feeder tension (I see the danger of grinding doing so) or would you increase the eSteps/mm by these 2% to compensate for this minimal "slippage" of the feeder? I think the increasing the eSteps is the better way.
  3. Thanks for your feedback, that confirms and extends what I have learnt about accuracy the last days. I agree that it seems best to give it the final perfection by adjusting the e-steps. Just trying that to tune that a little bit with every new piece. In the last iteration the difference between the lego pimples was already much less, having increased the e-steps by 2%.
  4. Not yet, but I have a Duet board waiting for a test. And then I will find out how Mark2 is to be implemented with that. But I think it will be 1-2 months until I get to try that.
  5. When switching heads the unused one goes to stand-by temperature, the active is heating up to print temperature. Is it that what you mean?
  6. I am struggling with one of my printer the last days. It keeps printing in bad quality with periodic underextrusion. After switching nozzles, taking the print head apart and cleaning it and switching between different filaments I can rule out head / hotend and filament. So I turned to the extruder today, it’s a Bondtech QR (https://www.bondtech.se/en/product/qr/) I am quite happy with for two years. I disassembled it and cleaned it, though there was not much dirt. Also I could not see any mechanical defect or wear. Remounted it and still there is this periodic underextrusion. Observing the print I can a clear correlation with one rotation of the Bondtech gripper wheel and when then underextrusion happens: You can see the set screw of the wheel pass by and the underextrusion happens in the same cycle. So the underextrusion cycle is identical with one full turn of the extruder gripper wheel which equals one turn of the stepper motor. Attached a picture while the printer is working on the second layer, you see the stripes of the thicker and thinner extrusion. So if it’s not nozzle, hotend, tube, extruder gripper wheel, what else could be the reason? Could the stepper motor have a defect in one area and loose steps just in like one fourth of it’s full turn? Or is the gripper wheel worn but I just can’t see it? How long is a gripper wheel lasting typically? I think in these two years it could have been 1.000-1.500 hours of using it. No abrasive materials, 85% PLA. I have both my printers modded as Mark 2 dual, so as a next step I could borrow parts of the 2nd extruder to check out if it’s motor or gripper wheel.
  7. In another iteration I find - or better: I am reminded - that temperature is a key issue influencing the extrusion quality. In hindsight not surprising really, I should know. But it seems I forgot by developing bad "standard procedure" habits. After dialling the temperature up another 15 C the striping disappeared completely and the dimensional accuracy is now perfect. While in the last round the stripes were much better and the dimensions of my lego struts 0.2mm too small. I went up from 190 C to 215 C now. I wasn't aware that the ideal temperature differs that much between 0.1 and 0.2mm layer height. It seems that so far I haven't had a use case where quality with 0.2mm mattered that much so that I didn't notice the "few percent" of underextrusion of 200 C on 0.2 layers. So bottom line, if you do these things right you will not get an underextrusion and/or grinding issue with 0.2mm layers: - proper bed calibration so that the resulting distance is in fact 0.2mm and not less - appropriate extrusion temperature
  8. After doing all this - cleaning drive gears, adjusting tension carefully, recalibrating the bed and increasing the print temperature slightly (for 0.2mm +10C seems reasonable, could also pay into this) - it's much better, actually totally acceptable. The stripes still can be seen a little. But now looking at the other printer - where I haven't noticed that issue yet - I find that these minimal stripes are visible too. So possible some form of this inconsistent extrusion on a large areas does possibly always exist, but is not relevant in most situations... I need to check the bottom of the good prints I made with the other printer if they also have signs of stripes. And I would expect that they have.
  9. It seems I was on a wrong track and it’s not the motor! Looks like it’s simply grinding / slipping of the filament due to too much pressure on the first layer! After swapping the motor I noticed signs of the stripes again on the start of the first layer and took down the build plate a fraction of a turn of the adjustment screw and it got much better. The pattern is still visible now, but only a little and I am convinced that’s just dirt in the drive wheel. Thinking about how I got there I find that there’s probably two reasons for that. First I had issues with clogged nozzles from certain filaments recently (it’s always tricky to switch from high temperature filaments back to PLA, now using separate nozzles) and I started to get used to overtightening the tension screw on the extruder. Which increases the grinding of the filament if it cannot move as it should. And second I am printing 0.2mm layers in the moment where usually I prefer to print 0.1 and do that 90% of my prints. So I seem to have adjusted the build plate for 0.1 - I often do fine-tuning on that visually while the skirt prints. That led to too much pressure on the filament during the first layer, to some decent grinding and just enough dirt in the drive wheels that the filament slips slightly each turn to release some pressure. I did not find a lot of dirt in the drive wheel the last days or I would have thought of grinding directly. It seems it doesn’t need very much dirt for this effect. Once there’s enough dirt to reduce the grip in one position it’s enough to release pressure and no further grinding is needed. Attached a cam still of the current print. The stripes pattern is much less, but still there. Next I will clean the drive gears another time, adjust the build plate properly, tighten the extruder pressure screw less and retry. Another reminder that the build plate adjustment is key to 3D printing... 😉
  10. Bondtech responds upon describing the issue to them: I'll take the motor apart tonight and have a look. I'll swap motors and retest tonight and check the possibly defect motor. I don't think it's nozzle temp. 1) it's too regular "in sync" with the rotation of the drive wheel 2) Why would that problem start now and I have never seen this before. Only if something changed or if a compontent on the mainboard went defect. Well... possible, but for me rather unlikely. But never say never. Let me do the test with the motors first, then let's see.
  11. I have now moved the gripper wheels of the right / second extruder to the left / first. And I got a surprising result: I get the same inconsistent extrusion pattern! See cam screenshot. So it’s not the drive gears, it’s the motor gear or the motor. If I seem to have observed that it’s in sync with one turn of the drive gear then it could not be the motor, given the motor turns 5 times as fast. The pattern would need to be much more dense if it related to one turn of the motor. But to verify I could try a quick calculation how much material one turn of the drive wheel would extrude... The drive wheel has a diameter of about 12mm, so it’s circumference is 12 x 3.14159 = 37,7mm. That‘s the length of filament extruded by one turn of the drive wheel. The volume of material is then 37,7mm x 6,4mm^2 = 240 mm^3. If the layer height is 0.2mm that would cover a area of 240 / 0,2 = 1.202 mm^2. If this was the first corner of my large rectangle that would form a right angled triangle with 2 identical sides of sqrt(2x1202)= 49mm. If the issue in the corner had a width of 50mm it would actually stretch across one quarter of the width of my object. Yeah, that’s about it. So it’s an issue of the outer wheel of the planetary gear. I need a new Bondtech geared stepper motor. To verify I will swap the motors tomorrow and see if the issue is gone with the motor of the 2nd extruder.
  12. Um. Thinking out loudly. I am currently printing the same file with the same setting and the same filament on two printers of the same hardware, so I am quite sure that it’s not a software issue. Or I would see it on the other printer, too. But the hint with the geared motor is a good one. It leaves the gripper wheel or it’s drive wheel as last point of failure. So I should swap the grippers between the two extruders and see what happens.
  13. Yes, I use it for my "Magnetic Tool Changer" modded UM2+. Which can use a bit more power as you have two hotends and in my case even two with higher power of 50W each. The plug is identical, so it's a drop-in replacement. So far I haven't noticed any quality issues.
  14. Satisfied with this: https://www.aliexpress.com/item/Top-Quality-24V-15A-3D-Prnter-Ultimaker2-Power-Supply-Adapter-For-Ultimaker-2-UM2-Extended-3D/32832288123.html
  15. You mean within the Bondtech extruder? Check with them if they have a replacement part for that. I think to remember they have a 3d model of their housing, then it would be possible to reprint it. But I would assume the resin 3d print is sturdier than a FDM print. And still I think that there is too much force on the extruder for some reason.
  16. Never heard of extruder motors dying. I bet the root cause is somewhere else. Worn bowden tube, bad / jammed nozzle, bad part in the print head. Or simply too much motor current so it overheats, ...
  17. Hi TrevDog, the board in UM2 is actually identical to the UMO board v1.5.7 in the technical layout, just much nicer on one PCB and more beautiful. And the UMO board has the same structure than the first UMO setup with Arduino Mega 2560 https://www.3dprima.com/de/ersatz-und-zubehoer-teile-3d-drucker/ersatzteile/ultimaker/ultimaker-original/a-20949 and a motor shield Something like this here: https://www.amazon.de/Controller-Schrittmotor-Treiber-Heatsink-Grafik-Smart-Display-Controller-3D-Drucker/dp/B01NCZ09Q5 In other words: UMO and UM2(+) board ARE some sort of Arduino. And yes you need a powerful power supply for the motor shield and hotends. Delivering 19-24V and 1-2A per Motor plus heater plus hotends.
  18. It’s the UM holes I cut out and both do fit, the UM holder and the iRobert one.
  19. Yes, that's the mount of the UM2 spool holder, so you can put any holder that fits this. And yes, it's iRobert's spool holder, one of the long versions, 80 or 90mm. https://www.youmagine.com/designs/low-friction-um2-spoolholder
  20. I designed and I am using this: https://www.thingiverse.com/thing:2183950
  21. You are right, you need a nozzle for 1.75. Otherwise the filament would be pressed upwards again and build out a big blob between bowden tube and nozzle, which you can't remove anymore as the blob is thicker than the bowden (given that's changed to 1.75).
  22. @neotko just ist watched your video on cabling the Duet3D board in the UM2. What firmware are you using? Marlin ported or another one? You then use the Duet display with, not the UM2 built in anymore? Cura works with it? What do you have to configure? As my UM2 board on my 2nd printer is broken (see other post) I am thinking about how large the Duet3D mod is in comparison to repairing the UM2 board... ;-)
  23. Flex wedge I would use 100%.
  24. The oozing issue of the blue filament could also be a temperature overshoot when heating up the new active nozzle. Using OctoPrint I have noticed that hotends tend to overshoot 10-20C on heatup and it takes 15-30s to get back down. A prime tower also helps this issue as the head will print the tower for 10s instead of your model and it has time to get down to the right temperature. The oozing happens at the prime tower instead then. But in fact different filaments have different viscosities (is that written correctly? Looks strange) and not only the optimum printing temp, that could differ 10-20C, but also the curve how fast they become liquid. I have one PLA that I can’t print with higher temp for higher speed because when setting it 10-20C C higher it’s to liquid to print nicely and oozes. So it might be both for you. Overshoot and 10C too much temperature.
  25. I have now ordered Duet3D Duet 2 1.04 Wifi Board and two PT100 adapters (for 2 extruders) and hope to have the time in the next months to convert one of my printers. Yes, months... too much work, too many projects, currently. 😞

Important Information

Welcome to the Ultimaker Community of 3D printing experts. Visit the following links to read more about our Terms of Use or our Privacy Policy. Thank you!