After further testing i am starting to understand some of the different issues you can have with pierce height and torch height control. the biggest issue was with the initial pierce height on thin material. The weight of the torch was the main problem. It weights 4.8 pounds..I made some counterweight springs to lessen the weight on pierces. i have some pics to show what i did.I got the weight down to 1 pound. Any lighter and the torch bounces. I was wondering what some of the high dollar torch height controls use. The cuts are pretty good now. Thanks again for the help
Industrial height control z axis slides can handle payloads up to 50lbs....are generally servo driven. Most that use steppers have mechanical brakes or electronic holding circuits. These systems all use ohmic contact as the primary plate sensing and adjustable torque sensing as backup. Speeds on the z axis are often in the 250 to 400 ipm range to shorten cut to cut cycle times.
Jim Colt Hypertherm