Hi all

I hope I'm posting in the correct place.

I have a company that manufactures windows and doors from uPVC profile. The production system is quite simple; cutting, welding, cleaning, beading and hanging. The profile we use is a sculptured system that is quite complex to clean off after welding and there are approx 13 different recipes.

The machine that does this job is a CNC corner cleaner, specifically this : EV470/300

This gives an idea of what it does (not the same machine):
CN-772 Fully Automatic CNC Corner Cleaning Machine ( 4 axes, 4 servo motors ) - YouTube



The machine is quite simple, it's two axis, X and Y, X being horizontal and Y vertical. All the system is Mitsubishi. The problem; about 18 months a go the Y axis started dropping and damaging frames. What we found was the the encoder for some reason is sending false pulses to the amplifier. The strange thing is this doesn't happen all the time. We have changed the amplifier, encoder cable and motor/encoder. We have everything wired as per Mitsubishi, we have mains filters etc. I'm pretty sure it is airborne RFI or similar as when the encoder cable is run externally away from the chassis.

Equipment on the Y Axis:

Servo Amplifier - Mitsubishi MR-J2S-70A
Servo Motor - Mitsubishi HC-KF73B

If anyone can help please do.