Ball Screw Vibration

[Coyote553]

Hello, need help to see if anyone has encountered this problem before and its possible causes.

http://www.youtube.com/watch?v=3BHwotPlyFw&list=UUuqGRDejszix1FmCYlHRFIw&index=1&feature=plcp]L470-1250 - YouTube

The noise is the ball screw for Z-axis vibrating. The motor is not rocking the ball screw back and forth that is visible.

I want to disconnect the coupling but want to have as much info before I do that.

[holbieone]

sounds like the drive is out of balance

[Coyote553]

sounds like the drive is out of balance

If out of balance how do you correct this?

[holbieone]

fist you will need to know if you have digital drives.

if you do there should be options in the software for tuning the drives

if not you will need to get the specs on tuning your drives

on an analog drive there's pot you can adjust one will be a balance pot (sets the voltage the same for both directions )

[Coyote553]

I found a previous post which describes problem I am having. I am trying to understand what he is talking about here.


"http://www.cnczone.com/forums/okuma/136703-okuma_ma_axis_vibration.html"

Problem: z-axis vibrates with slow movement .
Most worst vibration when pulsehandle is used or rapid at 10%

If actual position (wanted) is for example 300.486 and if you look actual (APA) coordinates, they vary from 300.48-300.54-> So machine never reaches "goal". No help of changing parameters.

In Fanuc and Siemens we have sometimes triggered servo (GAIN). But now problem was measuring rod.I think Okuma uses both pulsecoder and measuring rod(?)
We did take measuring rod wires off and no problem after that. Of course machine accuracy is not as good,but enough for us.
Z-axis measuring rod change is BIG job, because you have to take loads of parts to get access to rod.

[holbieone]

They're talking about disconecting the axis scale , a bad or dirty scale can cause the same problem
You will need to rule out one thing at a time