Mits FX20k doesnt cut round holes

Afternoon everyone.

After years of faithful service I am starting to have issues with my Mits FX20K.

The machine cannot cut circular holes any more. Holes of any size are out of round by 30 mics or more.

Unusually it doesn't seem to have any problems with square sided apertures.

Does anyone have any thoughts as to why this would be the case? Or how to fix?

Any help would be greatly appreciated.

I'd call your local representative and have a ball bar test done. There may be an issue with scres or drives.

Hello,

I have experienced the same issue with my Sodick; the problem can be traced back one of the guides being worn...maybe that's your issue? Again, not knowing the details of your Mits....

Mark

Artefx,

Do you know the machine's history? This is important because for a machine as old as an FX, I'd first suspect worn ball-screws (prolly ready for at-least the third-time). If this is the case, you have two options, in order:

1) Using the same setup location, the easiest test would be; try changing your G02 to G03 (or vice versa), so you are driving axes-motion on the less-worn side of the screw. (Especially if parts have been previously machined in repetitive production) If this change reduces your error by half or more, your parts may become acceptable, but will also prove the ball-screws are worn beyond accurate use.
(More of a test than a solution, but you might get lucky with your parts)

2). Try making your setup in a different place on the worktable. Most users set up on the front corners of the table simply because it's easier to access and so that's naturally where the most wear of the screws occur. For a workaround, try using a back corner or unused section of the table and you may be pleasantly surprised.
(A much better chance of improvement over tip 1)

I hope either or both both tips work, but IMO, you will still have to replace the ball-screws.

Bud Guitrau