Partly. Watch the idlers while a print is running. If the belt looks like it is hopping around in the idler or is walking up or down, or the idler is oscillating in the mount- all of these are an indicator that there’s something wrong at that spot.
You can also wiggle the idler when not printing and see if there’s play in it.
What if you print super slow, like 20mm/s?
I would turn input shaper off as another test too. I doubt it is affecting anything, but I’d want to know for sure.
The fact that it is close to the size of GT2 is really smoke around the belt system. Do you have a toothed pulley where you should have smooth? Or does a toothed idler have the wrong tooth pitch?
are you running klipper? did you run the pressure advance and resonance compensation?
yes, yes, and yes
I’m pretty sure not
They all came from Ryan, so I would assume not.
I ran one at 40mm/s yesterday and could still see it
only reason I asked is it is repeated and it sure looked like resonance. Did anything change since you tuned both?
It looks like resonance, but when you run a file like the input shaper tuning tower, you can see a clear difference between the resonance that follows the curve, and the vertical lines that are still there in the background.
I initially thought that it was just an input shaper thing also, and spent almost a week trying to get rid of it that way lol
Do artifacts at 20mm/s and 40mm/s have the same spacing/frequency? If so, since you changed the belt, and see exact same artifacts across 2 diff belts(?), then, I’d maybe try 10mm/s or slower air movments and see if I could visually see whether a specific idler/pulley is causing the artifact.
Or, f*** it and completely replace all the idlers and pulleys, am assuming they’re all correctly oriented like Jim and you chatted about earlier. Wondering if one of the pulleys/idlers is defective/clogged.
Consider disabling resonance until past this issue?
I have disabled and re-enabled multiple times throughout, as well as tried manual tuning and Klippain-ShakeTune.
Same for PA as well.
When I get home I will disable everything, and essentially back down everything to the speeds I run my stock Ender 3 Pro at, and run another print.
I believe so.
I have to assume so. I’ve assembled it multiple times and have never noticed a flat belt side touching a toothed pully, or vice versa. Will check again for completeness when I get off work.
I have considered that… I have already replaced the smooth idlers on that belt path, but not the toothed parts.
Noticed unexpected belt motion when the belt seems to overly grip/stick to teethed idlers. Shared slow mo clip…
Jamie spotted what looks like radial friction suggested lubricant. I’d try something that won’t deteriorate the belts.
Is your motor shaft bent or the pulley on it offset?
Interesting idea, does the artifact have size/distance that matches anything interesting like teethed pulley’s circumference? Is the artifact sinusoidal wave, or a sudden/asymmetric judder?
I haven’t pulled the motors to check the shafts yet, but when I installed the pulleys, I was very careful to make sure to slowly tighten the grub screw on the flat side first, then the other.
I will double check when I get home to see if anything looks off.
Im not at all familiar with this machine since I have not built one, but I was wondering… The way the bed connects at the corners, I’m assuming there is some sort of ball joint or something to allow for the bed leveling. Is there any play in those areas that would cause the bed to vibrate/resonate to cause the issue?
One of the early issues I found was that the screws weren’t tight enough on my bed mounts, and that caused some play/bounce in the bed, but I have it all tightened down now.
If I grab the bed and try to shake it, it doesn’t move without shaking the whole thing. I don’t think there is anything loose with the bed anymore.
My other thought has to do with a skew in the extruder gearing, but if the one axis doesn’t exhibit the same behavior, it most likely has to do with the motion of the motor and belt on the one side and the extruder is likely fine.
As mentioned earlier in the thread, if one of the toothed pulleys is mounted crooked, it may cause the belt to ride up on the pulley and at the top or bottom of the pulley, it may try periodically to jump onto the outer edge… kind of like a multi-geared bike does when the shifting isn’t tuned correctly, the chain would try to jump up and then drop back in place. The periodicity of the defect appears to be of the belt, so it could be a belt alignment issue. My v4 had this issue when the front motors were not tilted corrected when setting belt tension. a slight tweak by loosening a bolt and moving he motor and retightening plants the belt in the middle of the pulley,
You could try printing the same block twice but moving it by 1/2 the peak-to-peak distance. That will confirm that the locations of the peaks are relative to the motion system, not the model?
Did that already
Hard to tell in the picture but they are slightly off. Those 3 were printed at 3 different corners of the bed.
That model just happens to be the one I was using, but just a regular cube has the same lines. I don’t think it’s model related.
It’s on everything I print
Even round stuff
This seems counterintuitive to me. While I’m not above trying anything, it seems wrong to me to lubricate the thing we are relying on to grip.
Wouldn’t this make it more likely to slip and cause other problems?
On the idlers you don’t want it to grip. On the steppers or at the print head carriage you do.
