Machsupport Forum

Mach Discussion => General Mach Discussion => Topic started by: replicaprops on August 20, 2012, 01:24:08 PM

Title: On the fly z axis adjustment?
Post by: replicaprops on August 20, 2012, 01:24:08 PM
I am commonly running into a situation that requires me to stop the operation and go back to zero to make fine depth adjustments to my cutting bit. The problem is created by the fact that the surface I am engraving into is not perfectly flat and I am only engraving down .0025". The surface is extruded aluminum that I wet sand and pre- polish on a buffing wheel to get a mirror finish. then I set my zero at the corner of the stock. Because the buffing wheel does not leave the surface perfectly flat, the cutting bit will sometimes engrave some areas deeper or lighter than the other areas.

So I was wondering if there was a feature in Mach3 that allows me to compensate for lower or higher surfaces on the fly by clicking something on the computer screen instead of having to stop the program and manually lower or raise the cutting bit.
Title: Re: On the fly z axis adjustment?
Post by: Captain Midnight on August 22, 2012, 07:42:13 PM
Jogging is disabled while a program is running.
Maybe a spring loaded tool holder would allow for more even depth?
Title: Re: On the fly z axis adjustment?
Post by: Hood on August 22, 2012, 08:25:16 PM
You should be able to use the THC function. If you go to Config then Ports and Pins then Mill Options you will see an option called Allow THC Up/Down even if not in THC mode. If you choose that then it will allow you to jog the Z via external keys or you could emulate them from your keyboard. To set up external keys or emulate you would enable the THC Up and Down inputs (Ports and Pins Inputs page) and either set up the port and pin numbers if using real inputs or enable the Emulate options then choose the keystroke for each.
Lastly you will need to open the plasma screenset and enter the values you wish to adjust by in the THC Max/Min DROs. You can then go back to a mill screenset and your buttons/hotkeys should now jog the Z even when code is running.
Title: Re: On the fly z axis adjustment?
Post by: james elder on March 16, 2015, 02:27:02 PM
Ressurection of a thread, I know, but I have followed the instructions from Hood, thanks, but I seem to be getting only a one-hit, ie a z- or a z+, then no other movement, (this may be the correct action for THC, I don't know) and it doesn't seem to be related depthwise to the settings on the plasma screen, where the minus is .01, but I am getting about 1mm. Any ideas?