Two question. Auto-Z with VCarve bits and depth for T-Track

I was wondering how you use the Auto-Z with a tapered bit. Also, I’m going to router out space for some T-Tracks into my spoil board. How far do you usually indent the T-Tracks? I have two pieces of MDF so I’ve got about 1.5 inches to play with.

You can use the touch plate with a V bit. That plate is spring loaded so it won’t smash up your tips.

For the t track in the spoilboard there are a million ways you can do it, here are two:

And @Woodbrew

Maybe I misunderstand his question @Eric but the issue with a tappered bit isn’t the z axis, its the y and x axis. how do you tell mach 4 what the diameter of the bit is when it tapers (the bit won’t hit the sides of the touch plate at a known diameter) so that the center of the bit ends up where it is supposed to be. My solution is to do two seperate zeroing operations. I’ll use a quarter inch flat mill and tell mach 4 it is .25" and zero the x and y axis. Then I’ll put in my tapered bit and only zero the z axis (bit diameter is irrelevant for this operation). Does that make sense?

I didn’t watch erics videos as it is late but what I did is use two layers of mdf and set my t-track on the first layer and then lay another layer of mdf strips between the t-track. The only real issue for me is giving myself room to resurface my spoilboard (the second layter of mdf) a few times without hitting the t-track.

I do it the same way as @AncientCowboy.

The way that I think about it is that I am really trying to get the location of the spindle’s axis (centre), not the edge of any particular bit. This location (the x-y position of the centre of the spindle) will be unaffected by changing to other bits and “should” (ahem) even survive a restart of Mach 4.

However, I always check that it looks roughly correct before I hit the “Cycle start” button. (I click “goto working zero-x/y”, then see if the bit is more-or-less where I think it should be). I don’t trust Mach 4 100% to remember where it is; I had some early problems with loose wiring in the P&P box.