"1. Lets start fresh with new consumables in the Hypertherm torch....make sure they are a good match for the material that you would like to cut.
2. Choose some material....perhaps some 1/4" mild steel plate, and then program a simple part such as a 4" x 4" rectangle.
3. I would choose the 40 Amp consumables (and look at the machine cutting chart in your Hypertherm manual) 120930 shield, 220061 retaining cap, 120932 nozzle, 120926 electrode, 120925 swirl ring.
4. Make sure the ohmic wire from the PHC is attached to your retaining cap.
5. Use a programmed cut speed of 48 inches per minute, set the pierce height to 1/8" to 3/16" (3 to 5 mm) , pierce delay time to 1 second, cut height to 1/16" (1.5mm), and amperage to 40 Amps, and set arc voltage to 149, these settings are all out of the Hypertherm manual, and I know they work....with possible exception of the arc voltage as that varies from installation to installation.
6. Do an IHS test (the instruction manual will tell you how to do this...this will confirm the pierce height is correct).
7. Do a first test cut and carefully observe the torch to work distance....it needs to be 1/16". If too high, lower the arc voltage setting on the PHC, if too low, raise the arc voltage setting until it is just right.
8. Once the height seems correct, do another sample cut. If the height control is rising off the plate or crashing into the plate....then lets put the height control in manual mode and do another cut with the torch at a fixed height of 1/16", to do this you will have to ensure that your plate is level....so that 1/16" is maintained all around the cut perimeter.
Things that can go wrong and cause an arc voltage height control to provide inaccurate height:
1. If the cnc on the cutting machine settings are incorrect. The cnc must provide a height freeze signal in all corners, in small (under about 1" diameter holes) that locks out the arc voltage control to eliminate diving in these areas, the diving is due to the z , y axiss slowing down for cornering. If you see the torch dive and drag in corners, on kerf crossing, and in small holes and fine features...then you will need to revisit the arc voltage interface settings in your software.
3. If you are cutting along and the torch rises off the plate.....if it rises and stops at a certain height but keeps cutting....then simply lower the voltage setting until it is at the right height. If it continues to rise randomly, then there could be an issue with the pHC internally.
4. As consumables wear, expect the torch height control to move the torch coser to the plate. It is normal with any plasma/thc to have to increase the arc voltage as the consumables wear...in order to maintain the proper torch to work distance.
5. If the torch dives and drags often...and simply increasing the arc voltage does not work, and you are sure the cnc is freezing the height in corners and during decelleration...then check your work ground to your cutting table, a loose connection can cause thc diving. On some plate, such as small pieces or thin materials and especially aluminum, it is a good practice to have a welding cable with one end attached to the grounding (work cable connection) and the other end with a 100 amp welding clamp that can attach directly to the material you are cutting.
Please try the above, or at least report back to me with more detail and I'll try to help you out. You have a great plasma and THC system, I do not know much about the rest of the machine! perhaps with a little step by step testing, and new consumables are a must, then we can isolate where the issues are coming from.
If there would be a calibration issue wioth the Sensor PHC....the above tests will help us out. On this type of system it is important to set the arc voltage to whatever setting gives you the physical height required in the Hypertherm cut charts. The voltages listed in the cut charts are recommended starting points....but vary from site to site as there are at least a dozen variables that affect the relationship between voltage and height with any arc voltage height control system. Regardless, if there is an issue with part of the Hypertherm system we certainly will stand behind it as we always do.
Best regards, Jim Colt Hypertherm
we did this and the cuts did improve but not 100%