[CaliEng]

Hey Guys.I am having trouble with my gantry mill which I have been trying to figure this out. This is a custom made machine built years ago with its own anti vibration concrete foundation/metal base.Amplifier Drives : Indramat TDM 1.2-050-300-W1Motors : Indramat Mac 112B-LD-C (permanent magnet brushless motors.I have 4 motors, Z axis,Y axis, Master X and slave X.The problems started because the whole room got flooded from a broken fire sprinkler which was not monitored correctly and the water left running for 8 hours, which ins turn flooded my unit and bathed my gantry mill.The electrical cabinet containing the amplifiers drives got water in it and so did the drives. After letting it sit for a week to dry,I decided to turn it back on.It ran fine for a few days until one day something shorted and with a loud bang blew the 50 amp fuse on the Indramat TVM 1.2-050-220/300-W1/115/220 power supply. A few minutes before it blew the fuse for the 300VDC bus on the for the motors, I had noticed that one o the X axis amplifier driveslit a the "BS" red led, indicating that they was a short either in the motor, the motor power cable or the drive itself. Then it blew the fuse.I megged the X axes motors/cables and everything looked good.I removed the faulty drive and dissembled and diagnosed it. I found a "shorted" darlington transistor module. There are 3 of those and one had shorted out.I replaced the transistor module, cleaning the circuit boards with isopropyl alcohol and dryed them. I did the same with all the drives and power supply. I am glad I opened up all the drives because there was so much dust, carbon dust which is conductive( I machine carbon fiber parts) and I saw signs of water.I reinstalled all the drives, replaced the 50 amp breaker and turned the mill back on. Everything was normal, no abnormal noises from the drives or motors. That fixed the shorting problem.When I move the Y and Z axis with the handhweel, everything is operational. As soon as I move the X axis, it moves alittle and then stops responding.It seemed stuck so I disconnected the Master/Slave X axes from their individual motors because I figured out that the bridge must be skewed. I got help to wind the ball screws and return the axes to the home position. I set the gap for both ends of the bridge according to the original specs when the machine was built so the bridge moves straight.I turned the machine back on,moved the x axis with the handhwheel and the X axis worked fine. It looked like the rate of rotation for both the master/slave X Axis ball screws were the same. The X axis moved more than 60 inches indicating that the manual alignment worked.But when I stopped moving the handwheel, the X axes kept on moving as if it is looking for a feedback signal. I had to turn the power off or hit the emergency button to get it to stop.I turned the power off and turned it back on and tried homing the machine. Y,Z homed okay but the X axis started to run away (accelerate) before itstopped and displayed "Lag Axis Error) I know the lag error happens when I move the axis too fast and the motors cannot keep up with the control.Other signs I noticed that when I put the mill on standby (after being turned on), the x axis moves alittle and the bridge twists, one axis moves one end forward and the other axis moves the other end backward. I do know that to get the bridge (X axis) to move in one direction, both ballscrews will have to be rotated in opposite direction.I also noticed at times, one X axis balls screw would rotate faster than the other, thus skewing the bridge, which in turn makes it impossiblefor the motors to move the x axis. I then have to manually move it and align it in the homing position.I dont know why this happens because theslave is supposed to be controlled by the master for speed control.I did notice water in the bridge which houses the encoder cables and found them wet. I dryed the cables and cable tied them so they do not lay at the bottom inside the bridge in case there is more water. There are not indication of errors from the amplifier drives via the red fault leds.I am guessing that all these problems have a common fix and would be very grateful for any help. Regards,Roy

[CaliEng]

Hey Guys.I am having trouble with my gantry mill which I have been trying to figure this out. This is a custom made machine built years ago with its own anti vibration concrete foundation/metal base.Amplifier Drives : Indramat TDM 1.2-050-300-W1Motors : Indramat Mac 112B-LD-C (permanent magnet brushless motors.I have 4 motors, Z axis,Y axis, Master X and slave X.The problems started because the whole room got flooded from a broken fire sprinkler which was not monitored correctly and the water left running for 8 hours, which ins turn flooded my unit and bathed my gantry mill.The electrical cabinet containing the amplifiers drives got water in it and so did the drives. After letting it sit for a week to dry,I decided to turn it back on.It ran fine for a few days until one day something shorted and with a loud bang blew the 50 amp fuse on the Indramat TVM 1.2-050-220/300-W1/115/220 power supply. A few minutes before it blew the fuse for the 300VDC bus on the for the motors, I had noticed that one o the X axis amplifier driveslit a the "BS" red led, indicating that they was a short either in the motor, the motor power cable or the drive itself. Then it blew the fuse.I megged the X axes motors/cables and everything looked good.I removed the faulty drive and dissembled and diagnosed it. I found a "shorted" darlington transistor module. There are 3 of those and one had shorted out.I replaced the transistor module, cleaning the circuit boards with isopropyl alcohol and dried them. I did the same with all the drives and power supply. I am glad I opened up all the drives because there was so much dust, carbon dust which is conductive( I machine carbon fiber parts) and I saw signs of water.I reinstalled all the drives, replaced the 50 amp breaker and turned the mill back on. Everything was normal, no abnormal noises from the drives or motors. That fixed the shorting problem.When I move the Y and Z axis with the hand wheel, everything is operational. As soon as I move the X axis, it moves a little and then stops responding.It seemed stuck so I disconnected the Master/Slave X axes from their individual motors because I figured out that the bridge must be skewed. I got help to wind the ball screws and return the axes to the home position. I set the gap for both ends of the bridge according to the original specs when the machine was built so the bridge moves straight.I turned the machine back on,moved the x axis with the hand wheel and the X axis worked fine. It looked like the rate of rotation for both the master/slave X Axis ball screws were the same. The X axis moved more than 60 inches indicating that the manual alignment worked.But when I stopped moving the hand wheel, the X axes kept on moving as if it is looking for a feedback signal. I had to turn the power off or hit the emergency button to get it to stop.I turned the power off and turned it back on and tried homing the machine. Y,Z homed okay but the X axis started to run away (accelerate) before it stopped and displayed "Lag Axis Error) I know the lag error happens when I move the axis too fast and the motors cannot keep up with the control.Other signs I noticed that when I put the mill on standby (after being turned on), the x axis moves a little and the bridge twists, one axis moves one end forward and the other axis moves the other end backward. I do know that to get the bridge (X axis) to move in one direction, both ball screws will have to be rotated in opposite direction.I also noticed at times, one X axis balls screw would rotate faster than the other, thus skewing the bridge, which in turn makes it impossible for the motors to move the x axis. I then have to manually move it and align it in the homing position.I do not know why this happens because the slave is supposed to be controlled by the master for speed control.I did notice water in the bridge which houses the encoder cables and found them wet. I dried the cables and cable tied them so they do not lay at the bottom inside the bridge in case there is more water. There are not indication of errors from the amplifier drives via the red fault leds.I am guessing that all these problems have a common fix and would be very grateful for any help. Regards,Roy