Anet A8 Y axis vibration

[old_toymaker]

I have been printing with my printer now for about 5 months and I have been getting some nice prints, I did have a bad wire problem on the hot end fan and repaired that, however lately I have been getting a lot of vibration from the y axis. I have over 1000 hours on the unit now and the problem has just cropped up and seems to get worse with each print. I have disconnected the belt and checked the belt is good the bed slides freely so I believe the bearings are good. I checked the wiring and all connections seem to be fine so now I am stumped. The X axis motor is almost silent when it moves but the Y axis is very loud.
Has anyone else run into this problem, I could really use some help on this
Thanks

[MaddieG]

Could be a bearing issue, cheap machines don’t typically come with the best bearings for the long term so the ones on the Y axis might have worn out.

[old_toymaker]

I checked the 4 bearings on the bed and they are still good the bed moves very smooth on the rails I’m wondering if the stepper motor might be bad as it sounds very loud now and with the belt connected and the steppers off the bed is very hard to move in the y axis

[MaddieG]

Are your belts extremely tight? This can make it harder to move the axis, loosening them up a bit can help.

[old_toymaker]

The belts were pretty tight, I loosened them up but still vibrates. I have the Igus bearings on the y axis I think I will try replacing them with the stock bearings tomorrow and see if that makes a difference. I have ordered a toothed idler pulley and a new stepper motor to see if that helps.

[djcs]

I know this might be a pain, but pull the rods out and roll them around each other,
I had something similar happening with what I thought was a smooth carriage
but it turned out my robs were bent.
And the igus bearings dont allow for it at all as the tolerances are too low.

[old_toymaker]

I replaced the Igus bearings with the original bearings that came with the printer, that helped a little, the bed runs very smooth in the y axis now with the belt disconnected. I replaced the idler pulley with a toothed pulley. The printer prints pretty good but if I print over 30mm speed the Y axis still vibrates badly and the stepper motor gets very loud. I pulled off the y axis rods and measured there straightness on a granite and indicator and both checked out less than .001 Thanks for the suggestion by the way I had not thought of that. And still the problem remains. I have a new stepper motor and I am going to replace it maybe this weekend and see if that does anything.

[User_8735]

Did you managed to find what the issue was? I have been experiencing a similar issue with some of my prints lately, but not everyone. Im getting a lot of vibration on my Y axis movement, especially moving from the back to the front. This is only during a print. During normal Y axis movement commands, the beds moves freely with no vibrations at all.
And this does not happen with every print.
i went through all my bolts and everything seems to be connected. Then I thought it might be a slicing issue so I tried the same print from Repetier and used Slic3r, there was no vibrations … happy days … till 2 jobs later, now its happening again…

[djcs]

Hi guys, hope you dont mind me jumping here…
When I did the igus upgrade, not only did I find the rods bent, but I also found that the
bed carriage was out of square.
The only way I could solve this was by pulling it all apart and then measuring the distance
between the bearings etc and making it as square as possible before I reasembled.
With the belt off, and linear bearings, it should slide almost frictionlessly.
A little push and it hits the end stop.
With the igus bearings, it should be very smooth, with a little difference in the level of friction.

I also had to put a nut in the little cap area, as there was enough distance in mine where the rod would slide n bump against the cap. Noisy more then anything, but annoying just the same. But this was the difference in the level of friction.

Its the only thing that I could think of that would be causing the stutter minus a faulty motor.
Have you tried changing the motors over? This would help rule it out.
What happens in you move the bed from within the settings without printing anything?
Ie full backwards/forwards movement?
Have you tried printing something at the back of the bed as opposed to the front of the bed, to see if there is a “spot” where the shuddering starts? And vice versa of course…

Please let me know what the end solution was? It took me ages to get it right And dont give up, they are totally worth it at the end…

DJ

[User_8735]

Thanks for jumping in, any advice is always welcome!
No I have not tried to rule out any hardware yet because this was not happening every print or started mid print. It happened during some prints.
When sending move commands via Octoprint, its moves without any stuttering. This is why I have not given hardware much thought yet.
I have also replace my standard bearings with Igus, the bed does not move as frictionlessly as what you described. I will check the bars tonight for straightness as well as swopping out the motors.

Just as Im getting nice prints, this happens

[rafdotcom]

Hi sorry to jump in this as well

Not sure if you manage to find a solution to your issue …
So I have the exact same problem. Printing fine for months. Recently upgraded to a glass bed. First print after the glass bed was pretty decent
Then all of a sudden my bed has a stutter like movement but only on the right of the bed.

I disassembled everything bed related …checked both rods are straight, tried drylin and stock bearings, they glide smoothly over the rods.

Stepper seems fine, everything is aligned. Stepper is not under strain, no weird sounds!

When homing or moving y axis with octoprint or marlin there’s no issues y axis performs normally. This only happens when printing!

Any advice would be appreciated. I doubt it’s software related as I havnt messed with jerk settings etc … tried older gcode files to ensure it’s not gcode/software issue

[djcs]

Im a little confused on this.
You say it is happening only on the right side of the bed.

Im guessing you are seeing the stutter on the right side of the bed?
But everything is aligned…
Do your rods fit perfectly, or do you have space where the rods can move backwards and forwards a little inside the rod holders with the caps over them?
If you move the bed back n forth, can you hear the rods banging inside the caps?
Mine did, I had to put some paper in there to make it quieter.

I also found with mine, that I had to loosen of the bearing holders to the plate, and run the rods back n forth a few times to get them perfectly straight. Using a straight edge did not help me at all. It was easier to loosen them off, and tighten them up to the point where the bearing holder could move, but with a little force. Move the rod back n forth a couple of times after tightening each screw to ensure that the holders arent moving too much from the tightening of the screw.

It was a pain, I also found after all that fiddling that the distance between the rods in the igus bearing (much lower tolerance to error) was off by about 5 mm when the rods were extended. So this meant I had to loosen the whole plate sections together to get it all to line up correct.

Its exhaustive the steps you have to go through, especially with the igus bearings. But totally worth not hearing the original bearings clatter and the quality of the prints jump right up when you do get it sorted.

As a side note, also check that your threaded rods and nuts havent come loose and that the distances over them to the front to rear braces measure the same. Any movement here would cause weird warping and who knows what issues…

Hope this helps, Im only really able to give you answers from my own experiences, and I went through a very tedious time with my anet upgrade to igus, but now it prints fantastic.

DJ

[rafdotcom]

So my problem got more complicated

I removed the bed and went over all connections to make sure they snug and then removed and replaced the bearings with Drylin bearings.
The bed was smooth, could give it a flick and bed would move to the back smoothly.

Proceeded to re-install the bed and after hooking everything up it seems my Y axis is switched around

The bed doesn’t home to the endstop but instead to the front and because there’s no limit switch it just grinds violently and Marlin reports a homing error

For some reason … when I move the bed +10 the bed doesn’t move towards me instead it moves towards the endstop as if min and max have been reversed

When -10 it moves towards the front of the printer. -10 is all it can go tho. Bed doesn’t move thereafter

Checked belts are installed correctly. Stepper motor is correctly installed. Cables are fine.

When controlling via octoprint online interface. Front moves bed front … back moves bed towards endstop

When using marlin via the Anet display & buttons
Moving axis +10 sends the bed back towards endstop
Moving -10 bed moves towards front, away from endstop

I’m considering reflashimg marlin in the hopes that helps and I can go back and tackle my original problem with the bed vibrating… lol fun and games
Thank you for your suggestions … not sure where to start now