Belt slipping or stepper blocking?

I have a weird problem with my printer. I've had quite the rough ride with the upgrade to vCore 3.1 but managed to get it working. I've printed a bunch of files (PLA) and all seems well in paradise. However - what happens now is the following. At random moments during a print (or sometimes even during the initial mesh) it sounds like one of the steppers just blocks and the X-Y messes up. It basically shifts a few steps to one side, resulting in failed prints (the center is no longer the center). Sometimes it happens during the mesh but sometimes it happens after printing a bunch of layers. I've checked the grub screws, looked at belt tension, even double-checked the wiring - but I'm baffled. Anyone have an idea of what might be going on?
24 Replies
billyd
billyd•2y ago
Check your x endstop and make sure it is functioning properly and not shorting out when getting moved around by the print head. Or you've got a bad wire (or connectors) to a stepper or binding in the belts. That's all I can think of.
Trondin
TrondinOP•2y ago
Thanks, I'll check that out and report back 🙂
Trondin
TrondinOP•2y ago
I've double checked all the cables but can't seem to find anything wrong. I did manage to film what happens: https://youtu.be/zDI6ZS3Ovfk
Jaap de Koning
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Ratrig motion skip
My Ratrig v3.1 is dring me nuts!
ptegler
ptegler•2y ago
what current (power) setting for the motors are you using? also take a look at https://discord.com/channels/582187371529764864/1054265467591741511/1054265467591741511 and https://discord.com/channels/582187371529764864/844167067757182980/998324814509002944 Made a BIG difference in smoothness and noise
Trondin
TrondinOP•2y ago
I actually did that yesterday, did wonders for the X/Y - but I still need to do the Z (which are the ones you are hearing most now I guess). I'm running the default RatOS ldo settings ([include config/steppers/ldo/42sth48-2504ac/2209/24v-1.1a-*.cfg]) Run current in that config file is set to run_current: 1.1
blacksmithforlife
blacksmithforlife•2y ago
how tight are your belts?
Trondin
TrondinOP•2y ago
They are tight, but not like a guitar string.
blacksmithforlife
blacksmithforlife•2y ago
Can you upload your printer.cfg?
Trondin
TrondinOP•2y ago
Yeah sure
blacksmithforlife
blacksmithforlife•2y ago
have you also unplugged your x/y motors and then manually moved the toolhead around to see if you feel resistance in places? you need to first unplug your motors, because otherwise if you move them too fast you can feed current back into the board and fry it
Trondin
TrondinOP•2y ago
yeah, doesn't feel like any extra resistance. but I'll check it again.
Trondin
TrondinOP•2y ago
Trondin
TrondinOP•2y ago
just unplugged the steppers, and tried moving. It all feels quite equal for resistance - but when I move my carriage in X direction it also tries to move in Y; as if both are not turning at the same speed Coming back to this comment - would your guess be that they are too tight? also switched the Z-stepper wires now, its so much more silent and another update - it seems to be doing it at the exact same place now, three times in a row
blacksmithforlife
blacksmithforlife•2y ago
that happens when your X is skewed
Trondin
TrondinOP•2y ago
as in not square?
blacksmithforlife
blacksmithforlife•2y ago
could be. You want them just tight enough they don't slap the frame. Then use your ADXL to fine adjust
blacksmithforlife
blacksmithforlife•2y ago
my crude drawing. With your X axis being exaggerated. It is not 90 degrees to the Y axis
No description
Trondin
TrondinOP•2y ago
ah check. And thats adjusted primarily with the belts right? thank you so much for responding by the way. It's been driving me nuts.
blacksmithforlife
blacksmithforlife•2y ago
depends on who you ask. I used 123 blocks to hold it perfect against the front extrusion of the frame and then tightened the bolts. Then I put my belts on and adjusted the belt tension. Others say to keep the bolts loose, adjust tension on the belts until it is parallel to the front extrusion, then tighten the bolts. I think either works, but yeah you need to fix that
Trondin
TrondinOP•2y ago
I had to google 123-blocks but those look like a much better way to get the frame square; just insert some hex nuts and set them up
blacksmithforlife
blacksmithforlife•2y ago
Yeah, they are useful for many things. You can even get bigger ones like 567 blocks
Trondin
TrondinOP•2y ago
I've since measured (twice) the X-axis vs the Y, and it seems square. 123-blocks should arrive in the mail tomorrow, together with an ADXL. However - I've reduced belt tension by a lot and this looks like it is helping loads. First print is starting just now, I will report back after it hopefully successfully completes @blacksmithforlife . Again, thank you for your help so far. alas, it happened again on layer 5 or 6
billyd
billyd•2y ago
Are you over extruding? Perhaps the belt is slipping because you are impacting the printed part? Put zhop in your slicer and print again to see if it matters.
Trondin
TrondinOP•2y ago
I'll try that, and re-do the extruder tuning Extrusion was spot-on; now trying the z-hop Right, another update. I think I've found the problem; it was your remark about hitting the printed part which got my wheels in motion. It looks like the retraction settings got reverted during one of the Cura updates and it was retracting 6.5mm on an Orbiter. Put that back to 1.2 and it seems a lot better now. Benchy on the way! Allright, this looks solved. In the end there were three things wrong: Belt tension (way) to tight, retraction settings not correct and finally the nozzle was leaking; after tightening all seems well now. Thanks for the pointers @billyd60 and @blacksmithforlife
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