Problem- baldor servo tac and encoder cleaning?

[erikh206]

HI,
I just purchased a Tree 425, with Baldor servos and Dynapath 40 controller. The X axis is very jerky when jogging. Wide open rapid looks and feels pretty good. X / Y interpolating is notchy also unless feed is turned down to about 3 IPM. Otherwise straight X and Y moves look good when running a program. The machine is well lubed and the screw turns very easily with the bolt on the end. I have read where perhaps the tach and encoder are dirty? I pulled the end off and all looked pretty clean but did not want to start ripping things apart until I got some advise from you all. The brushes on the motor are very clean, free and have lots of meat still on them.

Can someone give me some pointers on how to clean these parts?

Thanks,
Erik

[underthetire]

It probably not a tach if it moves ok in rapid, Tree's will error out first during rapid. Get the drive tuning procedure from Bob at ZPS. You will need to pull each card out of the drive rack and use a DVM to set pots. Then set the axis lag using the set up page, and set them for 15 at medium jog. The set up sheet has all the details on it. I've also had the large capacitor on the drive cause this, they go bad and no longer can control the ripple on the drives.

[erikh206]

I do get occasional errors on x and y when it rapids in a program that read, "lost x axis feed back" hit reset to continue......

Do the cards need to come out if the pots are on the outer edge of the cards? Or is there another pot down on the side of the cards?

I will contacted Bob as you suggested.

Thanks again

[underthetire]

Still need to take them out. Can't get to all the test points with them in.

[erikh206]

OK, got it, Im waiting for a reply from Bob and will report back when I find something out. Thanks