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X Belt wobble with R2 parts  

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jonathon.b
(@jonathon-b)
Estimable Member
X Belt wobble with R2 parts

I’m still getting belt wobble on my X axis.

I was assuming the new R2 parts took care of this but it’s still there. Has anyone else sorted it out? I know there’s been other posts regarding this but thought it was fixed in the new parts

Posted : 12/03/2018 10:24 am
Kameron
(@kameron)
Active Member
Re: X Belt wobble with R2 parts

I have the same problem, received my kit for around two weeks with the new R2/R6 parts. Unfortunately the belt wobbles and the belt rubs on the left side of the idler (when I look trough the hole to the extruder). There is already black debris from the belt visible and sometimes I can hear the idler squeaking. Print quality looks good so far. When I check the belt status under "LCD Menu -​Support - Belt status"​ I see normal values...
Unfortunately, it's really hard to get to the belt fixation again without disassembling a lot of staff. I think it's a bit to tight.

Posted : 12/03/2018 12:06 pm
Steve
(@steve)
Estimable Member
Re: X Belt wobble with R2 parts

For me it was fixed after the installation of the R2 parts.
I don't know if it has anything to do with it, but I also switched to the new carriage (just the front part that holds the printhead, kept the carriage back original)

XL (5T) / MK4 / MK3S+-MMU3 / MK3S / MK2.5S-MMU2S / Mini / SL1S

Posted : 12/03/2018 1:14 pm
jonathon.b
(@jonathon-b)
Estimable Member
Topic starter answered:
Re: X Belt wobble with R2 parts

I wonder if it’s the pully with only one bearing and wobbling a bit

Posted : 12/03/2018 1:17 pm
jonathon.b
(@jonathon-b)
Estimable Member
Topic starter answered:
Re: X Belt wobble with R2 parts


For me it was fixed after the installation of the R2 parts.
I don't know if it has anything to do with it, but I also switched to the new carriage (just the front part that holds the printhead, kept the carriage back original)

I have both parts installed maybe I’m missing something

Posted : 12/03/2018 1:18 pm
Jason Foss
(@jason-foss)
Eminent Member
Re: X Belt wobble with R2 parts


I’m still getting belt wobble on my X axis.

The belt wobble is caused by the screw holes being oversized, and allowing the M3 screw that the idler bearing is riding on to rock / be crooked. The main thing that changed between the R1 and R2 versions of most of the files that don't have obvious differences is decreasing the clearance of the screw holes, because the originals were designed with ABS shrinkage in mind.

I'd recommend that you calibrate your extrusion to ensure you're dimensionally accurate in terms of your wall thicknesses (erring on the side of over-extrusion), and reprint the X idler.

Posted : 12/03/2018 6:08 pm
JuanCholo
(@juancholo)
Honorable Member
Re: X Belt wobble with R2 parts

i'm not a fan of how the part was designed that supports the idler on the right side.
the tension of the belt depending on how damaged yours already was before the conversion has an effect on pulling the belt unevenly.
after setting my machine up with the new parts i'm thinking about working on the idler with shims to try and back space it slightly so the belt sits slightly more centered. i would rather not start taking the machine apart again and editing the part homebrew there seems to be some adjust ability in the pulley that a washer might help. on the X-carriage there is also a lot of movement possible front to back with the belt depending on how much you packed it in to the new teeth design. i pushed both sides in all the way bottoming it out in the new carriage. if i look from above it still looks like the belts needed to get back more at least 1-2mm as the belt is not parallel to the shafts

“One does not simply use a picture as signature on Prusa forums”

Posted : 12/03/2018 8:32 pm
jonathon.b
(@jonathon-b)
Estimable Member
Topic starter answered:
Re: X Belt wobble with R2 parts

There were actually parts provided in my kit, noting has been printed by me. There B6 versions

Maybe a reprint would be in order one side at least anyway, i think i've got an easy way to install them after figuring a few things out today.

I guess its not really the end of the word but would be nice for it all to be perfect

Posted : 12/03/2018 10:30 pm
Bigdogbro1
(@bigdogbro1)
Estimable Member
Re: X Belt wobble with R2 parts

I placed tiny ball bearings I had laying around for 20 years that just happened to fit as side spacers to the pulley. I could then slightly tighten the pulley axle screw and hold it in centered position in the slot away from the plastic and not rub. No wiggle waggle and stays pretty much belt in center of flanges.

MK3 Kit, Designed, built 4x4 CNC Plasma Cutting Table, Motorcycles Bigdogbro's Adventures
http://www.youtube.com/channel/UC5djrxBeeOKB9_6rHnn6G8A

Posted : 13/03/2018 3:24 am
jonathon.b
(@jonathon-b)
Estimable Member
Topic starter answered:
Re: X Belt wobble with R2 parts


I placed tiny ball bearings I had laying around for 20 years that just happened to fit as side spacers to the pulley. I could then slightly tighten the pulley axle screw and hold it in centered position in the slot away from the plastic and not rub. No wiggle waggle and stays pretty much belt in center of flanges.

That's a good idea, I have some new pulleys being delivered today with dual bearings, might just need a couple of spacers either side maybe

Posted : 13/03/2018 12:48 pm
Kameron
(@kameron)
Active Member
Re: X Belt wobble with R2 parts

I placed tiny ball bearings I had laying around for 20 years that just happened to fit as side spacers to the pulley. I could then slightly tighten the pulley axle screw and hold it in centered position in the slot away from the plastic and not rub. No wiggle waggle and stays pretty much belt in center of flanges.

Interesting! Can you post a foto of your pulley?

Posted : 13/03/2018 1:34 pm
jonathon.b
(@jonathon-b)
Estimable Member
Topic starter answered:
Re: X Belt wobble with R2 parts

Ive just replaced the pulley with a two bearing 20T and the wobble has pretty much gone

Posted : 13/03/2018 6:30 pm
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