Symptoms of Belts too tight

What would the symptoms of your belts being to tight? This shaking issue is getting annoying. LOL

Shaky Axis

If you watch closely you can see the x/y axis vibrating as it moves. It moves smoothly when moving faster like when homing.

I have tightened and loosened the belts no change. Played with acceleration and jerk no real change.

It also does it just travelling in X or just travelling in Y. Now I used cheap ass chinese bearings could I have a bad bearing or 2 in the X/Y Center section?

The rails look rough but are actually really smooth.

I have the same issue. I don’t think it’s my belts and they are quite tight. I actually think it’s a combination of 1. dust on the rails and bearings and 2. xyz gantry is not square.

Number 2. above is my key issue I think because in order to square it, I do like others have said and run the x and y against physical stops to square it, which my x/y needs to move one of the braces a 1/2 " to do so. Also, when milling I noticed that the motors locations are smooth, it is the xyz assembly that jitters. One other thing is that cutting diagonals leaves ribs in precisely the same places. So the errors are repetive and reproducible. So it may be something else perhaps a gcode issue as well.

I know my is square as well. I use an end stop on one side and a block on the other. 99 out of 100 times it finishes square too.

Yes exactly the motor rollers move smooth although you can feel the vibrations in the belt. I guess just vibrations transferring throughout the machine.

I guess a test would be replacing all the bearings in the X/Y center section. I do not do much router cutting to see repetitive inconsistencies.

But on mine the shaking is predictable when it is running diagonal on raster laser engraves.

What are your rails made from @P3DCNC?

25.4mm stainless. 25"x49" working area.

Same rails… I am running 48x48 working area.

Nice. I’ll troubleshoot mine tonight a bit. BTW, circles are also an issue.

They are jagged i assume? Mine are round just not smooth.

Same. Interestingly, I’m cutting 3mm deep with an 1/8" bit through a 3/4 piece of plywood at 1000mm/min, and the patterns repeat through all the layers perfectly.

The video seems to be unavailable. Can you post it again?

I did a wood sign that had a 1/3 circle feature from 1.5" cedar and same result the pattern was repeatable thru the entire cut. was cutting 1mm deep with a 1/4" bit.

Are your bearings of the cheap chinese variety as well? There was a point that my machine would make loud grinding noises but those seemed to have stopped recently. Not sure if that was the chromed finish getting chewed of the rails or a ball in the bearing getting chewed up… It seemed that the timing of the grinding was repeatable on the rail.

I do not have any issues accessing the video with the link.

No grinding. Part of my planning tonight is to remove the belts and see if the movement is binding anywhere.

i did that the other day… Mine moved very smooth. All my tensions bolts are so loose they are almost falling off. I did find tightening them made it worse.

What do you have your driver voltage set at? I think if I remember correctly I have mine a 0.7

If it’s not mechanical, which I will be checking tonight, then my next guess is firmware.

Could it be that we are running settings that are too coarse? I must admit this will be an area I haven’t touched in a while. But I am using RC7 pretty much stock other than the usual changes.

Another thought I had was to compare milling a circle near a corner of the bed and one in the middle of the bed and see if there is an improvement in the corner milling where it’s stiffer.

I haven’t touched the voltages. They are stock from Vicious1 but are now wired in Series.

90% of all my laser work takes place is the first 400mm of my axis. I have only had one job go beyond 600mm in either direction.

I have tried 1/32 stepping. I am currently at 1/8 stepping. Problem still exists.
Problem existed in parallel and series.
I have been meaning to move back to RC8 but have not got that far. I was running it for a bit and at that time no change.

I have the same issue and have narrowed it down to the center assembly. I took my center assembly off and did some running and everything was nice a smooth. As soon as I install the center assembly (I am using the old design as I purchased my parts from here last May) I see the shaking. I have tried to loosen up the bearings in the center assembly but it does not seem to make a big difference.

I wonder if we loosen off the bearings in the center assembly that are not related to tension on the bars… I know i have mine locked down tight. If they had a little wiggle room perhaps would absorb the vibration so to speak. I have had this issue across 2 versions of this machine as well. Old and new parts, conduit and smooth stainless.

@vicious1 do you have any ideas. Definitely seems to be something in the center assembly.