Need Help!- Koike and hypertherm

[rick sroka]

around October 2008 we started experiencing a problem where the hole locations on some of our parts were out of location by1/4 to 5/8 in. This has only been in the Y-axis. We determined that if we cut parts from the middle of the table and beyond, the machine runs fine. It is when we place sheets near the machine “home” that we see inconsistencies in the parts. Some other items to note are that not all the hole locations are off, not all the parts are bad, and the part profiles and hole sizes are within specification. We have checked all the mechanical properties of the machine and not found anything. We have had the servo motors checked out. We have added additional grounding wires in case of electrical feedback. We have also run the “Rosetta pattern” 3 times and it came out good. Koike has sent a service tech to check the machine and he was unable to find anything wrong.

[jimcolt]

Can you priovide more details in regards to the model of the Koike machine, the plasma system, the cnc controller, the software you are using and the height control system? I would be more than happy to help you get this situation resolved....

Best regards, Jim Colt Hypertherm

[m230042]

If I was there , And it was only on the front half of the machine I would suspect the Y encoder/motor cable as it may have rubbed trough in the nylatrac grounding out one of the encoder lines causing the controller not to see the pulses comming from the encoder. If it can't count the lines then it will go long.

Small motions may not skip enough pulses to be noticed.

I would swap motor/encoders first. Just for fun.

The problem doesn't show on the back half of the table because the affected spot is laying on the floor stationary.

Marv