Router bit not milling full depth

**cropwell** · 15-05-2020

Originally Posted by beemsquar2

Hi Kitwin, I'm using the same method I use for all bits I lower the bit onto a thin piece of paper and set it when I can just move the paper, but it's not pinched. Not the best method I know, but it seems to work well enough. I would love to by a zero setter at some point.

My zero setter is a piece of brass bonded to acrylic. The brass/acrylic was turned on the lathe to make the faces parallel and a 4mm hole drilled in the brass for a wire to connect it to the BoB.

I have a macro for Mach3 which lowers the bit (earthed, in my case through the spindle) onto the brass and when it touches it retracts the tool 10mm and sets the tool to Gauge thickness + 10mm, so zero is top of material, bottom of gauge.

If everything weren't packed away whilst I am refurbing my workspace during lockdown, I could send you a copy of the macro and instructions, assuming you use Mach3.

Cheers, Rob

**beemsquar2** · 15-05-2020

Cheers Rob, if you ever get it out again, feel free to send the macro, that would be very useful!

I ran a few tests today, but I'm still confused. I measured the bit before and after a cut, with and without tabs, it's definitely not the bit slipping. I had 19.06mm before and after. Out of the two cuts, the one without the tabs was better with only 1mm remaining, the tabed cut had 1.6mm remaining. I copied my whiteside compression bit, which I know works, changed the pass over and bit setup to match the 3.175mm bit and ran it again. Still no difference. I even tried making a pocket 11mm deep and it was perfect.
I am at a loss as to what is causing it!
I will try and post the G code tomorrow to see if someone can see any issues with it, but as far as I can tell its correct. I might try just for sanity sake to run the g code for the 3.175mm bit with my whiteside bit in a piece of scrap to see if that cuts through the material to the 15.6mm depth, which might rule our the code.
The only way I can get it to cut all the way through is to set the Z height at 1.6mm below the actual z height of the material, so I know it can cut through.

**JAZZCNC** · 15-05-2020

I was tired last night so I blaming that for not thinking of this before.!! . . Check the tool table to make sure you haven't got an height offset entered for that tool number. It's about the only other thing it could be if it's not slipping and the code is correct.