by Rando » Sun Oct 04, 2015 2:31 am
There's a 20-mil offset (Grrrr....) that is apparently buried inside the controller.
When I touch-off, I use "no" touchplate, but instead use an 0.020" piece of sheet metal. That seems to give a very accurate height, as long as there is minimal cupping of that sheet metal.
Before I did that, when I was touching off directly from the (Aluminum) stock, it would always bite 20 mils PLUS the first layer height.
In cases of non-metallic stock, I'll subtract 20 mils from the number the controller calls it's location after the touchoff. So, if I start at a random distance up, 1.53 inches, and then touch off using the 0.375" touch plate, it will go back to 1.53 inches relative to the material height. Except guess what...that 1.53 it claims it's from the surface? Yeah, it's **really** only 1.33 inches from the surface. So, using the Set button I'll SUBTRACT 0.020 from whatever number it has for Z. That way when it plunges to zero to start the cut, it's actually at zero, not 20 mils inside the material.
Hope that helps; it sure has fixed my first-layer problems.
Regards,
Thom Randolph