[sphinksvt]

I recetnly aquired a bridgeport R2E3 boss 8 series I cnc a couple of years ago. someone robbed the FMDC board and one of the servo controllers out of it before I bought it. I have now finally found a used FMDC and servo controller but am getting an axis limit on the screen. I had to jog the z down past the home switch to get it to home out. Now when I hit execute it will home the z and then alarm out. The x and Y limit switches will drop out the drives when tripped and I have checked the switch string. What is my next step in diagnosing and fixing my machine. The flow chart in the manual says to hook up the FIST. However, the manual I have is for a R2E4 so I do not know how or what I need to do this on the R2E3. Any help would be greatly appreciated. Thank you.

[John Bennett]

Have you checked the home switch position (Z). The servo will turn home till it hits the home switch and continue turning untill it finds the index pulse on the encoder and then rotate back. If there is not enough distance between the home switch contact point and the limit switch, the servo will hit the limit switch before the index marker on the encoder. You might also have the servo motor 180 degrees out of rotation in relation to the belt, causing the index mark to be just missed on the first rotation.

[sphinksvt]

What was happening was this. I would turn the machine on hit execute to home axis and the quill would move up onto the limit switch and shut the drives down. I would enable the drives and jog the quill down and the machine would shut down jog mode as soon as the Z came off of the limit switch. I would hit execute and it would start the cycle all over again. To fix this I took the access panel off and held in the upper limit switch in so that I could jog the z down past the home switch. That seems to have fixed that issue. Now when I hit the home command the z moves down off of the home switch and back up. However, that is all it does. There is an axis limit on the screen at all times and I can still execute a home command but all it does is move the z down and up then shut the drives off. I looked and the z is about 1/8" away from the upper limit switch.

[sphinksvt]

TTT