mevander
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Posts posted by mevander
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We were discussing that the regulator seemed to be pretty badly tuned. Is there a description somewhere how I would go about changing the parameters?
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Hi.
What is a normal temperature variation while printing? I've been wondering about it a while but forgot to ask. When my fans are starting up I have +- 10C in variation and when they have stabilized at 100% I have +- 5 C. Sounds OK or too much?
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Just wanted to update to let you know that a new PTFE-coupling and new hotend nozzle didn't solve the issues
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I agree that it is a bit confusing with all the different users and input around this issue. Just to add to the confusion, I had to print a detail for a work setup today. I set it at 0.1 mm layer thickness, 20 mm/s and 220 C. It looked horrible already at the second layer. I increased the temperature to 230 and then the different lines barely managed to touch and it still looked pretty awful. I increased the flow to 120 % which made it look almost ok and at 130% flow things look like they should!
I'm going to remove the hotend today, clean it and check it for any burnt material that might be creating resistance to the feeder. We have a spare hotend that we might install and test as well and I'll let you know what we find out.
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@mevander - sorry - it gets confusing when 3 people have posted in the last 3 days with similar but quite different issues and I'm too lazy to go back and read all your posts again.
I feel like we ruled out underextrusion because you can print the cylinder just fine. That leaves Z axis. You said it was fine but - I think that on the top layer of your cube the Z must be moving too far. Really nothing else makes sense. The top is underextruded. The gcode is fine. You can print the cylinder fine so and your extruder is accurate (within 3%) so the onloy thing left is that the Z axis moved too far on the last few layers.
This is a common issue on UMO but not common at all on UM2. I guess I'm kind of stumped. Is your Z screw twisted or bent? How did you do the Z movement test? I guess I would do the following:
Get control of your Z axis again with bed and head at room temperature. Move Z axis off the surface of the glass by same amount as your part - or a little less. Then slip a stack of paper under the nozzle. Measure the thickness of 10 sheets of paper with a micrometer and divide by 10. Then move the Z axis by this amount many times and slide one sheet of paper under the nozzle each time. Feel the friction of the paper as it slides in each time. Are the Z movements consistent? Or are they variable? Repeat over a few mm (at least 20 sheets of paper. 30 sheets might be better).
I'm expecting the Z to occasionally move 2X as far as intended (and other times maybe 1/2 as far as intended).
If this test passes then I want to go back to underextrusion and see a closeup photo of your test cylinder that you say printed fine.
Hey, we're extremely glad that you're here and helping us at all. You're allowed to be both confused and lazy
I can check the z-axis again. We normally see that the layers start separating from the 4th layer or so, so it's not only the top surface that's wrong. This leads to the shell not being attached to the infill and the parts are not very rigid. By the way, I have what is called an indicator on wikipedia, a high resolution single-axis profilometer with a dial that's normally used for testing and calibrating milling machines. I can see if I can attach it to the print head somehow and then try to step it and see how it moves. It'll be fairly small steps but I think it has a range up to a few mm.
I've attached a photo of the latest extrusion test we did about 2 weeks ago at 250C.
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How about a short test instead at:
240C .2mm 30mm/sec 100% flow
I did test 240C, 0.2 mm, 20 mm/s and 100% flow here: http://umforum.ultimaker.com/index.php?/topic/5375-top-layers-not-touching-um2/?p=71121
Today I did a had the same issue with a 0.1 mm layer run at 40 mm/s as well. I have a feeling that the problem is getting worse ...
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3% error is tiny. Not noticable in the final part.
Did you do this test? I forget:
http://umforum.ultimaker.com/index.php?/topic/4586-can-your-um2-printer-achieve-10mm3s-test-it-here/
Hullo.
Yup, I get nice 10 mm^3/s cylinders at 230C and above.
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Right! I managed to get pronterface running and tested the z-motor and the extrusion. The z-axis seemed to perform well enough but for the two tests I did with the filament retraction I ended up getting 97 mm instead of 100 mm. It's a pretty small error though so I'm not sure it's responsible for me problems.
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Thanks gr5, I'll try to run some more tests today. I did a long run over the weekend at 230 C, 0.2 mm/s, 40 mm/s and 120% flow. The item looked better than we've seen before but still a lot of gaps between the lines.
I was thinking, is there an idea to try to measure/calibrate the nozzle size as well? If this would be a bit on the small side it would also push things in the wrong direction.
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We checked our hotend as well but as far as I can tell, it looks pretty nice. We also swapped to a new glass plate to rule out a non-flat surface and did a factory reset and realignment of the bed. Still same result :(
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Hmm, I have a similar shape on my filaments after pulling them but didn't think much of it
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I just spent a few hours with my colleague going over the machine. We tested the extruder to check that it was firmly seated (it wasn't perfect so we adjusted it), check the stop screw for slippage and checked the position of the filament vs the knurled axis. We also tested removing a few meters of filament from the spool, straightened it and ran a test with it like that to check that the increased curvature at the end of the spool didn't increase the friction in the bowden tube too much. We also did another atomic clean that looked very good. We double checked the filament diameter and it's a perfect 2.85. We also were advised to see if we could try to increase the current to the motor but apparently it's capped at 1300 mA so we couldn't test that.
The tests we did still resulted in the same kind of structures we've had before. The only thing that seemed to make a difference was if we manually pushed the filament pretty hard into the bowden tube while feeding it (to help the motor). I'm guessing that this would be the equivalent of increasing the flow or lowering the diameter.
I'm guessing that this means that there needs to be more material flowing but that it's a calibration/setting somewhere that is wrong?
Here's the last test we did with the ultimaker filament after all the cleaning and alignments:
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And here's my test cube (ran the gcode directly at 220C):
This was probably one of the worst prints so far. I also tested a 240 C, 0.2 mm layer and 20 mm/s print with a smaller test cube and it didn't work either. I'm going to take a good look at the extruder motor shaft and see if it's been sliding or something else today.
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Hi again.
I managed to check my other Cura settings as well:
- Solid infill top and bottom checked
- Spiralize and only follow mesh unchecked
- infill speed 0
I can try the high temperature printing tomorrow morning and see what happens.
If there is a problem with Z-stage or extruder calibration, how is this best tested?
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Hi again.
Thanks for all the help. My spontaneous answers that I can give without going back to work is:
- flow is set at 100% (even tried 105% without any change)
- Diameter of filament matches filament (checked with caliper)
- Ulticode is used
- 20% infill and 0.6 mm - 1 mm top and bottom used with 0.1 mm and 0.2 mm layers
I'll check your other suggestions and get back.
Thanks again!
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My problem with the under-extrusion theory is that I can't seem to fill in the top surfaces (or surfaces anywhere in the print) running at 1.6 mm^3/s while I'm able to produce nice extrusion test cylinders at 10 mm^3/2. Would this indicate that there is some other settings then that is causing my under-extrusion problems that is not active when running the extrusion tests?
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Well, I've run the test cylinders and get 10 mm^3/s without any problem from 230C and up. At 220 C I get up to 7 mm^3. So I would assume that there is something else at play here?
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And here's the picture:
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I just printed Renthals test cube and it looked very nice up until the 4th layer where the lines started spreading again. This also coincided with when the fans started to come on a bit more ...
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Thanks, I missed that thread. I'll make sure to read it and follow it. We've been using both OS X and windows versions of Cura and I just recently had the same issue with 14.09.
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I've been suffering from the same problem. I posted in another thread but should have seen this instead. My tests and description is found here: http://umforum.ultimaker.com/index.php?/topic/7401-top-layer-the-distance-between-the-lines-of-plastic/?p=70736
We've seen the same thing with PLA/PHA from colorfabb and with XT as well.
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I did some new tests yesterday and today and tried 0.2 mm layers at 220 and 230 C at 20 mm/s. I also tried increasing the flow to 105% while printing but without any effect. Today I did a new print with 0.1 mm layers at 40 mm/s and 220C where I get okey top surfaces on some places but still gaps to the inner shell.
If this is related to the belt tension and I've tried moving the short belt motors as far down as possible, is there anything else I could try?
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I'm also interested in conductivity
Normal temperature variation?
in UltiMaker 3D printers
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Hmm, regardless of what goal temperature I set in the M303 command it never goes up to more than 155C. Is it OK to run the test at this lower temperature?