Hello Vladuinoire; paul is incorrect. if you make one cylinder the master and the other to sync you will have a problem when the master is to far ahead. The slave will never catch up. I tried this using a Arduino and gave up because reading two linear glass scales and doing the logic was locking up the board. So I thought. It turns out my code was causing the lockup. I didn't find it until I switched to a mesa board and using linuxcnc. I made a custom comp and it did finally work after switching to closed loop drives. After all that I found that one cylinder was leaking and so old no parts where available so I ripped it all apart put new cylinders on and went mechanical sync.