[davedoubleu]

Have got a Bridgeport Interact 4 Series 2 with a Heidenhain TNC 151 controller , the spindle is running faster than is shown on the screen. The machine will run below 500 revs, but anything above that the F is lit up on the screen and the traverse will not function . I think this is probably something to do with the feed drivecard . Does anybody know of any way of repairing this other than replacing the drivecard. Thankyou

[machintek]

When the commanded spindle speed is different from the actual spindle speed by 20 percent, the control will go into a feed hold.
First check all of your control parameters to make sure the control output to the spindle drive are correct.
This machine had 2 types of spindle drives. The older ones had a Contraves. the newer ones had a KTK. There may be a problem here or the spindle motor or tach as well.

George