Very very weird issue, looks like z wobble, but....
-
@iamthebest22 The larger thrust bearing may slowly get pressed in further into the plastic mount. You could use a spacer under it.
-
oh good idea, another spacer didn't think of that, thanks!
I do have the smaller 9 x 20 x 7 on the way, and that I know will not press into the plastic mount, should I use that instead? it's 20mm wide and the mount is 22.3mm so it won't press into the mount, should I use that?
-
It's been almost a whole month, but Spring break yay! I finally have time to mod the machine to try and fix the z wobble issue. Here's what I've done so far:
- metal brackets everywhere I can on the machine for rigidity
- changed all three 12mm lead screws to 8mm ones
- Changed to high quality jaw couplers from Zyltech.
- Thrust bearing between the jaw coupler and stepper motor and spacers so the weight of the big bed isn't causing possible floating issues
Here's a pic of the print, it looks like there's no more z wobble, but I can't tell for sure because my head suffered a partial jam.
with that being said, is it suppose to pause before a layer change? it wasn't doing that at the lower layers.
video (ignore the partial jam): https://www.dropbox.com/s/ntekqxoq4obdfc0/2019-03-22 18.24.16.mp4?dl=0
-
Pauses at the layer change during a Z move could mean you might have a too low Z speed, acceleration, or jerk in your config.g. Or if you have retract on layer change, it could be the extruder speed, accel, jerk, retraction settings.
It'll be hard to see any z wobble with such extruder issues.
-
@Phaedrux yeah It just finished reprinting today, and... YES! no more z wobble for sure now. There are some slight layer inconsistencies, but that's due to the filament (3kg +-0.05mm tolerance). I dunno which 4 things I did fixed it, but I can print for sure up to 720mm with no problems (thing can print up to 750mm my print was only 720mm so haven't tested the last 30mm :P).
With that being said though, this circle was about 30% smaller than the other one (140mm diameter instead of 200mm). Should I maybe try a bigger one? Or no it doesn't matter.
was also printing at 0.4mm layer height (0.6mm nozzle), should I also try 0.3mm to see if it possible gets worse there?
By the way about the pausing, it was retraction, but now here I'm stuck, because it's in vase mode, so obviously no retractions, but it started doing it above this height as you can see in this pic near the top:
https://www.dropbox.com/s/jxl6ldozlbhdxs4/2019-03-23 09.50.39.jpg?dl=0and I can't seem to find the setting in retractions in Slic3r PE that does that. Any ideas?
-
Well vase mode still has Z movement and if the layer height is quite high (like 0.4) and the model isn't very big (like a 140mm cylinder) it may need to execute a large z move to keep up. I think if you reprint with lower layer height it might not do that.
-
@Phaedrux oh okay so I should be good now with this printer? I'll do more testing, but if I understood your comment correctly, I'm good now in terms of the z wobble test?
-
Well I merely offered an explanation for what could be happening. I'd still do some testing to confirm that your issues are actually fixed.
-
@phaedrux Ah okay, what's a good test you can recommend me to do to see if there's still z wobble at very tall heights?
-
I think you were doing the right type of test just try a larger cylinder and lower layer height.
-
okay gonna try a 200mm one and 0.3mm layer height and reporting back on MOnday.
-
Make sure you've got all other confounding factors eliminated before trying to verify the wobble is gone. Tune your heaters, calibrate extruder, belts tight, lead screws lubed, etc.
-
I tuned my heaters, and calibrated extruders thrice to make sure. The usual checkups as you've mentioned at least twice. Also using sewing machine oil to lube my lead screws
. Wow I didn't know untuned heaters can cause wobble o.o. Will report on Monday. -
I didn't mean that it could cause wobble just that you want to eliminate any other factors that could show as issues.
-
Hi,
If you are content to manually level the bed you should be fine with 4 guide bars near the corners of the bed and two 8mm lead screws, one on each side of the bed at the center.
You can drive both lead screws with one motor using a belt.
Frederick
-
@Phaedrux ah okay, I got another problem though right now, I changed the layer height to 0.3mm in slic3r PE, and all of a sudden it start underextruding, the extruder turns at half the rate it's suppose to be. I didn't do anything to the esteps nor the firmware/config.g itself, I only changed the layer height from 0.4mm to 0.3mm and now it suddenly starts doing that. Changing just the layer height back to 0.4mm and it goes well again. What is going on?
EDIT: I noticed something interesting, in the file name in the duet ui, for the files layer height, for my suppose to be 0.4mm layer height, it says 0.3/0.4mm, but I'm sure in slic3r PE I didn't set any 0.3mm,
for the suppose to be 0.3mm layer height it says 0.3mm/0.3mm. What's going on here?
-
@iamthebest22 did you set the first layer height differently to the rest?
Can you post your gcode file so we can see what's up?
-
It's long, so I won't post it all here, but here are the two different gcode files:
0.3mm: https://www.dropbox.com/s/m7eyd5tk2uhhbt9/Circular cylinder for testing 0.3mm layer height.gcode?dl=00.4mm:
https://www.dropbox.com/s/1b97hv35gqxeelj/Circular cylinder for testing 0.4mm 200mm wide.gcode?dl=0no the first layer height is the same. for each.
-
G1 Z0.3 X1 Y1 F6000 ; move to prime position G1 E6 F60 ; prime 6mm of filamentThat's where it's getting the first layer height as 0.3mm from. It scans the file for the first relative Z movement.
One way to get around this is to move the nozzle prime gcodes into a macro, and then calling that macro with M98.
-
Oh I see, but does that have any actual effect on the printing itself? Because that doesn't explain why my extruder suddenly turns at half the speed at 0.3mm layer height and underextrudes but doesn't do it at 0.4mm layer height?
