Adding second Z touchplate for tool height offsets
Posted: Mon Feb 27, 2023 9:27 pm
I have a 4x8-foot gantry style CNC router with an ATC spindle, and I'm just now getting around to designing my fixed toolrack. Right now, I'm using one Avid touchplate to set tool height offsets, as well as the Z0 position at the top of my workpiece. I should also add that I have a vacuum table with an MDF spoilboard which will be routinely surfaced, creating a problem when I want to add additional tool height offsets as the touchplate will no longer be the same Z distance from the spindle Z home.
As I see it, I have two options right now:
As I see it, I have two options right now:
- Build a rigid cradle for the Avid touchplate on the new fixed toolrack. This rack will stay a constant position from spindle Z home and set tool height offsets. I can also remove it from the cradle and place at the top of my workpiece when I need to set Z0, though this is going to be a bit of a pain as my workpiece XY0 tends to be on the opposite side of the machine. I can design this from 1/4" 5053 aluminum, laser cut, TIG weld it, and attach it to the 40x80mm tool rack extrusion.
- Purchase a second tool touch off like this model and dedicate it to setting tool height offsets only. I can keep the Avid touchplate on the other side of the machine, closer to where I normally set my workpiece height. This touch off plate also does not require a separate clamp wire like the Avid touchplate. I know it's possible to rewire the Avid touchplate to eliminate the clamp wire, however my ATC spindle does have ceramic bearings so I'm not sure if it's conductive. I need to do further testing here.