SoliForum - 3D Printing Community — Y axis major shifting

Re: Y axis major shifting

2014-03-13T13:20:18Z

I had same thing with my stock x carriage. After much trial and error replaced with surstepr drivers and problem went away

I still after 20 prints had bad circle problems and skipping in x-y as well as a x shift constantly caused by the z rod. Same spot every time shifts to the left and comes back in. Makes a hump on the side of all my prints.

So after my last failed y skip print. I pulled the carriage off and replaced with linear bearings, new polished rods in both x-y and printed new x-y carriages as well as but bearings in place of the bushings on the rear Y shaft. I was going to add the additional bearing block but the stock rod is so rough I couldn't jam a bearing that far over even with dremel sanding the rod down and it is 6mm not 5mm. SO weird but all the replacement items are 5mm for the pulleys but I can not source a polished 5mm rod just 6mm

So long story short.. the bearings were huge difference in free motion. i can push the right side, non driving, of the x carriage and the whole x carriage will slide on the y carriage effortlessly and without any yaw front to back from the other side like the SD one does very bad.

I know you might not want to make those changes but the driver was a must have fix if you have y problems because no matter what you do mechanically the driver will be the problem, it is an easy fix/swap and cheap like $12.

Now just along the bearing g upgrade, I did see a much sharp x-y resolution in my print and the noise and clunking went away (almost) still some slop in the bearings sitting in the carriages but x-y look good but I did still y skip after all that. So I found the belt tighten tension was key. and I missed that after install a few times. i recently tighten down and tighter then before because I can with the bearing. I also increased the speed too

So i backed speed to pre bearings, adjusted again and looks super clean. Now I suspect that even with bearings my surestep current is low since it can over accelerate now and maybe slips or overshoots more the skips per-se so I will play with more current on the Y, and acceleration values (which you can turn down too)

sorry if this is not a full answer but just insite

Re: Y axis major shifting

2014-03-11T20:15:28Z

calibration and lubrication. If that doesn't do it adjust the VREF's

Re: Y axis major shifting

2014-03-11T19:56:43Z

Well I went through the belts and such again and seemed fine then during the print I heard a click/pop sound and it shifted in it's y axis again. Really disheartening D:, Not quite sure what to do.

Re: Y axis major shifting

2014-03-10T19:14:54Z

When it was making the sound I did it with the printhead far right, center and far left. Each time made the sound when moving forward. It's not doing it anymore granted I have since messed with the belt tension.

Re: Y axis major shifting

2014-03-10T19:05:19Z

@talsiri, does it matter if the printhead is all the way left/right when you have the y-axis move 100mm? if this makes a difference then you may have the y belts binding each other even if they are the same tightness...

Re: Y axis major shifting

2014-03-10T19:02:56Z

Sounds to me like your side belts are not equally tensioned and aligned. That is the sound of the belt skipping a cog on one side. All of this is assuming that "chunk" sound is what I imagine in my head

Re: Y axis major shifting

2014-03-10T18:23:51Z

When I was manually moving they Y axis through RH everytime I'd send a command to move the y axis 100mms it would make a chunk sound only when told to move towards the front but not when told to go back towards the home point. It did it a quite a few times but now It's not doing it at all. Any thoughts on what caused that and I'm assuming whatever that was is causing the skips.

Re: Y axis major shifting

2014-03-10T17:52:13Z

I just went through the same thing. In m y case it was not mechanical, rather it was a bad stepper driver (Palolu). I was able to replace it and everything is running fine. If you're using a Sanguinololu or RAMPS board, you can at least replace the driver. If you have the newer Printrboard, it get tough unless you're very good at replacing SMT components.

A couple of other things to check for:

1. Overheating. put a fan on the electronics and see if it still does it.
2. Check for correct Vref voltage . If your voltage it to low, it my not have enough torque to move the printhead smoothly, and if you have a bit of a bind in the filament spool, it may skip backwards when it tugs on the filament.
3. Check for mechanical binding (belt tensioning, rough spots on the rods, lack of lubrication, etc)

If everything checks, yet you still get the stepping, it my well be a bad stepper driver.

Re: Y axis major shifting

2014-03-10T16:37:44Z

Yea thats the video I already followed and it still did it. I'll do it again and start the print again butbi do not think that's the problem as I have printed a smaller file with 133 layers without and stepping.

Re: Y axis major shifting

2014-03-10T03:11:54Z

Go take a look at this video. This helps loosen up and improve the Y axis movement.
http://vimeo.com/55031028

Y axis major shifting

2014-03-10T02:18:47Z

Have an issue with the Y-axis shift back all of a sudden, after 20 odd very successful and happy prints.
I've tried the different the different calibrations but it keeps turning out the same way but shifting at a different layer count.

Could it possibly be just this file as I have since tried printing a small cylinder and get no y slip at all (maybe because the cylinder was such a small surface area?) Also all my previous prints were a much larger surface area than this one so honestly got no clue on what might be my issue. Any help would be fantastic