buzzing noise and slight vibration on downward Z

[Roy Esslinger]

My home made cnc router has a G540 controller and when it goes down to cut in the Z it makes a buzzing noise and the whole table vibrates as the router is going down to cut. It seems to cut just fine and my projects turn out just fine it is just annoying and worrying to me. Is there some kind of adjustment that I need to make on the stepper motors? or is this normal.
Thanks to all of you for your great help

Roy

[ChrisInEstes]

Perhaps the buzzing/vibration is from the steppers/servos creating a resonant frequency with your machine. Mine will do that sometimes in the X Axis. Try setting the Z Axis travel rate to a different speed, and see what happens.

Chris

[PaulRowntree]

How long has it been since you lubricated the threaded shaft? Dirty Z rails ?

[martin54]

Has it always done this or is this something new?
Does sound like it could be a resonance problem & if it is you should really sort it because although it might not be affecting the quality of the finished items it will shorten the life of the stepper.

[Roy Esslinger]

I think it is a resonance problem and I don't know where to go next, I guess I need to go into Mach3 to change the Z speed? I also keep everything very clean and wipe it down all the time with denatured alcohol to get off the gunk it builds up around the bearings and rollers on the rails.

[martin54]

Alcohol does a pretty good job of cleaning most things but it will remove pretty much everything leaving all you screws, bearings etc dry, you should be thinking about some kind of lubrication.
Does this only happen on the one axis ? Are the motors all the same & set up the same way? Not familiar with gecko drives, I know they are well respected but not sure what sort of settings you can alter, I would be checking what you have set the current to first on the drive, check what supply voltage you are getting at the driver.
Drivers I use can be fine tuned using a software package that is available for them so it's quite easy to ensure all 3 drivers are set up correctly.

[Roy Esslinger]

Martin, what kind of lubricant do you use

[jimwill2]

I had that experience from a metal sliver that made it's way into the top of the Z-ballscrew. I had to take it apart and remove it. It was a chore getting it back together.

[martin54]

Roy sorry missed this earlier, I use a very light machine oil, something similar to sewing machine oil BUT all my screws are covered by bellows so I don't have to worry about the oil picking up dust & dirt particles. If your axis is open then would be an idea to use a dry lubricant, something like a graphite spray that will work without picking up contaminants.