Yes I’ve thrown every single idea I can come up with at him. And everything he has tried at least 3 times lol. At this point I am frustrated because it doesn’t make sense and it’s bringing back PTSD from my V4 build lol.
I’m glad he has a lot more eyes on it now that are a lot more experienced than me
I have no input here but I like watching the hive mind at work.
Sorry we were out. I hope this works. https://www.google.com/url?sa=t&source=web&rct=j&opi=89978449&url=https://www.reddit.com/r/Reprap/comments/2txp2a/so_im_suddenly_getting_this_strange_wave_pattern/&ved=2ahUKEwju7qPj5sWGAxVWhIkEHasqOj8QFnoECA4QAQ&usg=AOvVaw01k4k6aMMpxpRPYR_pf7J0
It opened in reddit for me.
So just looking at the v4 build, i dont see much with linear to give those waves. I think what they were talking about were those barrel bearings!!! Sorry for posting bad info
Perhaps you can print something in vase mode and see if the wall thickness is going thick/thin, or if the wall is wandering laterally.
Also, this caught my eye, suggesting that the pitch is not constant, unless this is a trick of the light.
Given that it changes so much with layer height, I’m thinking it has to be thick/thin and not wandering.
I “think” I printed one in vase mode already, but I can’t find a picture. I’ll run another when I get off work.
That white print was an older one and had other issues as well, so I’m not sure if that one is a good thing to base anything off of. It was just the only print I had with a round part on it.
I can run the round part again today as well and see what it looks like
This looks really familiar. My V0 suffered from this and I do remember it was a pulley alignment issue. The pattern is from the belt teeth.
Forgive me if this was already mentioned but did you make sure the pulleys are perfectly(ish) inline with the proceeding idlers? If the belt rubs on the idler flange or rides it you get that pattern. Adjusting the pulley on the shaft so is aligned with the following idler fixed the issue - at least in my situation.
I will check through it later today. I’m not sure how much adjustment room I have on the idlers, but I’ll see if it looks like any can be better aligned
Yeah I think the way I did it was reference the horizontal extrusion and adjusted the pulley on the motor shaft so that the belt was perfectly parallel to the extrusion. But I also had the advantage of the belt being directly above the extrusion. I’m sure you could do that with the MP3DP by using a printed offset block or something. Good luck!
If your idlers aren’t aligned with each other then that has to be a problem in a printed part. If your motor pulley isn’t aligned then you can adjust that one. But I believe you aligned yours the same exact way Ryan and I both aligned ours so I would expect that to be correct
I used this method
But I’m not above going back through and making sure it’s all aligned. It would be great if it’s that easy to fix 
That’s what I thought you did and the same thing I did. But probably still worth a check
That is pretty nuts. I hate chasing these things.
I think I need to work out some sort of troubleshooting print steps, or find a good guide. Someone has surely made one.
My guess is a linear rail issue. Since you feel it nice and smooth with no load, I propose there is a load being added. On the X rail that could be the load of the extruder adding a twisting load and it is getting chunky, the Y rails if they are not co planar then you are twisting them to be in line with each other. I think JJ had this on his build in some form. The Y truck to X rail part was angled pretty bad for some reason and when connecting them his rails got chunky enough that he did not print with it. He bent or adjusted them if I am not mistaken. Maybe a truck print with elephants foot twisting the plate?
P.S. Now that I say that I wonder if that is what is going on with my one funky rail. It felt smooth to me as well.
by “when the belt is off”, I mean, everything else is fully assembled, just the belt is removed. So the XY is all still moving together.
With it like that, moving the core around by hand feels smooth through the full range of motion.
Just wanted to clarify and make sure you understood what I meant by that
If you go real slow by hand with the belts off, you feel no chunking at all?
Dang, we need Scooby-Doo and the gang for this mystery.
I didn’t…at least not to what my untrained hand could detect as abnormal.
If I can’t get this figured out without another round of disassembly, I will definitely try again when i release the belt.
I had checked before and my Y rails were perfectly square with each other, but some things have probably changed since then, so I will check again later today.
Mine was a bad print on the part between the aluminum for the trucks. One side was pushed down and the other was pulled up. I reprinted and that issue went away
which part? the spacers or the truck?
The truck. The spacers were good.
