Y axis stuck

[poolwiz99]

Machine homes perfectly fine runs in slow speed fine in fast mode y axis sounds jammed

[Bob]

1. Check for anything on or under the machine that could be jamming the movement.
2. Check for proper feed rates. You may have a feed set too fast. This one is most likely if you have been trying for faster machining.
3. Clean the drive screw.
4. Lubricate the drive screw.
How's that?

[djl]

By sounds jammed do you mean it is still moving but making a “grinding” noise.  I had the same issue  - y-axis making noise.  I lubricated the ball nut.  Unscrewed the ball nut so it was free to rotate on the ball screw and then lubricate it, turning the ball screw at the same time.  Turned the ball screw so that the ball nut was moving towards the front of the machine.  Idea was to get the grease as far into the ball screw as possible.  I had to do this three or four times, running the machine for a couple of hours between doing the ball screw lubrications.  I now have a quiet running y-axis.
To realign the ball nut, run it to the back of the machine and then tighten the cap crews evenly in a crisis cross pattern  Do not over tighten the cap screws.

[dadealeus]

Feb 26, 2023 10:01:25 GMT -5 poolwiz99 said:

Machine homes perfectly fine runs in slow speed fine in fast mode y axis sounds jammed

Mine did the exact same thing a while ago and I think it's simply due to less attention being properly paid to the maintenance of that screw and bearing set because of its location. I'd take the advice of djl and try your best to re-lubricate it.

Basically, the most common causes of a bearing seizing at higher speeds are inadequate lubrication, incorrect bearing preload, improper mounting, and contamination. By re-lubricating it via djl's advice, you're taking care of improving 3 of those 4 things. If that doesn't work, you might need to look into a replacement ballscrew nut.

[poolwiz99]

I wasn’t very clear the machine homes correctly I can then move it in any direction in slow speed x,y,z and it moves fine change it to fast speed and only x,and z work hit the y button and doesn’t move with jamming sound changed manual speed to 2600 from 3000 and it works not sure what is going on ran a project like that and ran fine

[Bob]

The Y axis is moving the highest weight (gantry + spindle). If it is moved too fast, the steppers will lose steps and make that grinding noise.

[dadealeus]

Feb 26, 2023 18:14:51 GMT -5 poolwiz99 said:

I wasn’t very clear the machine homes correctly I can then move it in any direction in slow speed x,y,z and it moves fine change it to fast speed and only x,and z work hit the y button and doesn’t move with jamming sound changed manual speed to 2600 from 3000 and it works not sure what is going on ran a project like that and ran fine

Yes, that is exactly the issue I was speaking about. The steppers skip when the bearings are generating too much heat at that speed due to one or more of the 4 issues I mentioned.

You can either continue to run it more slowly or you can lubricate the heck out of it for max performance. However, this issue will continue to get worse and you'll need to slowly continue reducing speed until you address the root problem.

I'm guessing that the issue generally starts when the gantry is somewhere near the middle of the machine during a long transition from front to back or vice versa, but it probably doesn't occur if you were to just start it from the middle and move it to the front or back - that's due to the heat buildup in the bearings on longer movements.

Again, lowering the speed will prevent this for a while, but you're just buying time before the steppers max out their torque again and you need to reduce again.

[poolwiz99]

That makes sense it was really cold in the shop maybe that also has something to do with it

[poolwiz99]

Thankyou everyone for the suggestions I think temperature had a lot to do with it went underneath and the grease was extremely tacky so cleaned the screw then lubricated it with new and runs on perfectly