Need Help!- Bridgeport 720 Interact with Y-axis drift when in programmatic cutting

Hello All,

I am having problems with my 1989 Bridgeport interact 720 with Heidenhain 351/355 controller.

After two years cleaning and rebuilding and creating a fusion 360 post, I think I have found why the machine was for sale in the first place.

When programmatic cutting the Y-axis is drifting at a constant rate, you can see on the screen Y changing, yet If I just manually make a cut it is square and Y does not change.

Here is a picture show the problem, the first arrow is showing the drift and the second is showing a manual cut that is square.

Any ideas?

Thanks, Bryan

Attached Thumbnails