Y-Axis belt stiff/too tight? not sure?
Hey Prusa Peeps,
Heads up, I'm pretty new to all this!
So yesterday I swapped out the bearings on my Y-axis to the Igus bearings (what a difference) Put everything back together and whilst checking that the bed was moving correctly on the Y belt, I noticed that whilst it does glide smoothly pushing the bed toward the end stop, when moving toward the front (toward the LCD) it gets quite stiff and requires a - slight - force, by force I mean a little more of a push, however when it is then fully pushed forward and in line with the LCD, it requires quite a bit more of force to push it back toward the end stop, once it gets to maybe 10mm or so away from the LCD it's fine and glides relatively smoothly. I've tightened the lug nut on the Y axis motor and it cant be tightened any further, the belt also makes the 'guitar chord' noise when I flick it so it does appear to be tightened enough. I've tried loosening it but still the same, also when I ran the self test after, at first it seemed that the belt was skipping, after a couple of adjustments this stopped but of course was very loud as if it was scraping or something maybe? I'm about 98% sure that the bed is orientated correctly when I put it back on and I'm not sure what my next port of call should be so I thought I'd put it out there to you the expert community? 🙂
Edit: Here's a clip I took of it last night to maybe help better:
Re: Y-Axis belt stiff/too tight? not sure?
Igus bearings requires to have perfectly parallel smooth rods, but even if it is the case, you still can have issues with them, depending on the tolerances of your rods. Moreover, even without visible belt skipping, they can have a bad impact on the quality of the prints since they may required more force to be moved.
It is not really advised to use those bearings in the MK2.
Re: Y-Axis belt stiff/too tight? not sure?
Hey, thanks for the reply however plenty of people use Igus bearings and have no issue. Also the rods are parallel as the xyz calibration passes and they slide smoothly. The issue definitely lies with the belt in someway shape or form
Re: Y-Axis belt stiff/too tight? not sure?
Also the rods are parallel as the xyz calibration passes and they slide smoothly. The issue definitely lies with the belt in someway shape or form
Passing the calibration does not mean that the rods are parallel to each other.
I would suggest that you measure the distance between the rods at front and back; there will be a small difference that you may wish to correct.
Peter
Please note: I do not have any affiliation with Prusa Research. Any advices given are offered in good faith. It is your responsibility to ensure that by following my advice you do not suffer or cause injury, damage…
Re: Y-Axis belt stiff/too tight? not sure?
And when you move with your bed to the end it hit the endstop ok?
Re: Y-Axis belt stiff/too tight? not sure?
Interestingly, no! It slides along the rods towards it fine and seems to line up with the actual endstop fine, it just doesn't 'click' though it does push against it, from what I can make out the 'click' is actually at the top of the end stop?
Re: Y-Axis belt stiff/too tight? not sure?
Is the button on the microswitch in line with the v mark on the bracket. ?
Regards Joan
I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK
Re: Y-Axis belt stiff/too tight? not sure?
Hey Joan! I'm not sure of that one, I'll have to check this out later after work, thank's for the insight, I'll look into it and revert!
Update: it appears to be perfectly lined up against the endstop, I made a minor tweak to the position of the front Y belt holder and it will hit the endstop with a 'click' but againstillrequires a little force for it to actually click! I'm attaching some pictures here of positions and where the belt starts to catch when moving it forward. Apologies for the little blur, poor camera, awkward angles! Should I just remove the belt and put it on again? Can this be done as is without taking half of it apart?
Re: Y-Axis belt stiff/too tight? not sure?
Some addition photos
Re: Y-Axis belt stiff/too tight? not sure?
Igus bearings requires to have perfectly parallel smooth rods, but even if it is the case, you still can have issues with them, depending on the tolerances of your rods. Moreover, even without visible belt skipping, they can have a bad impact on the quality of the prints since they may required more force to be moved.
It is not really advised to use those bearings in the MK2.
OK so LaPointe appears to of been correct (sincere apologies for dismissing you so quickly)
I removed the belt completely and the heatbed to ensure I had orientation of the bed correct(it was) and I noticed that even without the belt the same issue was occurring. I moved the frame a little and believed I had fixed the issue. The endstop was now 'clicking' seemlessly and it appeared to be smoothly running along the rods.
However, ran the self test - Perfect. Ran XY Calibration and it passed the first 'iteration' perfectly, on the second 'iteration' it began to drag the paper on the first probe point- I believe I need to lower the pinda probe?
Secondly, the issue isn't completely resolved, when it was running the calibration, I noticed it was still getting a bit stuck toward the front of the LCD, particularly around Y+195. Here it started to have difficulty. I'll upload two further videos shortly showing this. The first with the belt having difficulty appears to of passed but the second is it's current condition. Is this just further fixing of making it parallel? Can someone confirm this? ( I spent 3 days in the first place making it parrallel to pass calibration initially and this is my most painful part of it so I'm hoping not) However if peeps could confirm then I'll thank you all for your feedback and mark the thread as solved.
Vids incoming in next post.
Re: Y-Axis belt stiff/too tight? not sure?
Videos for more detail:
Re: Y-Axis belt stiff/too tight? Possible bearing problem
OK so to add a little more clarity to the situation. It may be that I have the wrong IGUS bearings.
The ones I have are RJZM-01-08 which are apparently 16MM in OD? Apparently I should be using RJZM-02-08 which are only 15MM in OD?
Could this really be what's causing this? I would think not due to the fact that the inner diameter is the same on each, the 1MM of a difference for the outer diameter should only have difficulty with it fitting to the bed I would think but it fits to the bed fine just like the stock bearings and I placed them on top of the stock bearings before fitting and they appeared to be exactly the same size?
So could it be its that they are the wrong bearings or is it that I need to do some more parallel calibrations? Or could it simply be that the UBolt is too tight on the bearings, perhaps I should loosen the screws ever slightly?
Re: Y-Axis belt stiff/too tight? not sure?
Have you read this topic?
On my side, after reading it, I'm definitely put aside the idea of using Igus brearings.
Re: Y-Axis belt stiff/too tight? not sure?
in honesty, most threads that I've read or indeed videos that I have seen relating to Igus bearings have been wildly positive.
Have you come across the opposite?
Update: This issue appears to of been resolved. I played around with making sure it was parallel and all endstips hit, xyz calibration passes, noise gone, except for a long one when starting a print where it hits the y end stop but this doesn't appear to be causing any issue, it's only for like 2 seconds. I think for this I just need to fine tune the parallel.
Now however I have a new issue, completely unrelated to do with the extruded stepper motor and filament. It's loading and extruding it from loading absolutely fine but when trying to the v2 calibration, the first line or two is fine and then the stepper motor makes like some sort of clicking sound and it extruded reallllly thin layers. Below two links of videos highlighting this issue. . Could it be that filament has expanded during the few days fixing the original issue and this is the problem? I had no issues printing prior to any of this and I didn't touch the extruded whilst replacing the Y bearings:
Re: Y-Axis belt stiff/too tight? not sure?
It's also worth noting that if I extrude manually via settings>move axis>extrude- it's absolutely fine, I extruded 500 and not a problem. As soon as I ran the v2 calibration or any other print it started happening again and I get these blobs on the printed filament before it printing hair thin. Pic attached shows this. Afterwards I extruded 200 manually again and once more it was fine. At one I point I moved the Z axis all the way to the top and the filament snapped so I'm wondering if my filament is just goosed?