Okay, this may not be the right place to post this, if it is not, please feel free to correct me. I’ve got this bit in my Fusion tool library. As you can see from the picture and the specs, it’s tapered to a fine point. It’s also flat from the center out, only round on one side.
I just finished using it to cut the inlay you see in the second picture. If you take a closer look at the picture, the inlay is not cut dead center even though it is positioned dead center of the stock in Fusion.
I believe this to be an error on my part when I do the XYZ probe on the CNC controller. If you look at the probe in the third picture, the way the operation works is it probes Z first, then X, then Y. It does this by bumping the bit up against the top, right side, and rear side. Problem is the bit is tapered.
Now, when I enter the diameter of the bit into the XYZ probe parameters for the probing operation, I’ve been using the tip diameter specification, which is .005. However the diameter of the bit where it contacts the probe is much greater than that, yet still not the full shaft diameter which is .25
Bottom line is I don’t know how to set the probe operation for this bit, or which of its numerical specifications to use in the controller, but I’m clearly doing something wrong.
When using a bit like that, you need to use a standard (square for example) endmill to probe XY, then replace your bit with the engraving one and probe Z. Hope this helps!
I’ve done what @jarrfarr said. But I’ve also done the following when I’m doing something like a simple engrave where the location doesn’t have to be within a few thousandths.
step 1) Probe Z with touch probe
step 2) Use joystick to move cutter to side of material
step 3) Use joystick to move cutter down until Z value is something like 0.005
step 4) Use joystick to move cutter to corner, eyeballing the location
step 5) Set X & Y zeros at that point.
This is quicker than changing bits twice and probing twice and gets you very very close. Good enough if you are not locating holes or something that needs to match up with something else.
Slightly more wasteful, but guaranteed to keep everything centered, is to add a profile cut as the final operation. As long as you keep XY origin in the same place everything should come out dead nuts.
For probing I use a .25 round pin specially designed for just this. No cutting edges and a flat bottom. Probe x y and z then switch to whatever bit is next and probe only Z. I find that even with the sharpest pointy butts the Z probe is spot on.
