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With the rotary axis now fully operational, it’s time to add touch plate functionality and modify the tailstock mount on my Gatton CNC’s rotary axis.


The tailstock mount is 2 long pieces of t-track with an MDF spacer separating them. It mounts the tailstock just fine, but getting the tailstock lined up with the center of the chuck ended up being a giant pain. I needed to come up with a solution, and luckily the manufacturer of the tailstock gave it to me.

Recess in the Tailstock Housing The recess in the bottom of the Tailstock Housing

The tailstock housing has a slight recess cast into the bottom of it. This recess is about 3/32” deep, and just over 1 1/2” wide. I found that a piece of 1/16” thick flat aluminum bar stock would fit in that recess perfectly, and give enough clearance to allow the tailstock to slide back and forth when I had the mounting bolts loosened. I had a piece of 1 1/4” wide, 1/16” thick flat stock, so I cut a piece to length and mounted it on the MDF section of the tailstock mount, making sure that once mounted, the tailstock would line up with the center of the chuck for the full length of the tailstock’s travel. With that lined up, I mounted it to the MDF with 1 1/4” long wood screws.

The mounted tailstock The mounted tailstock – much easier to properly align with the chuck.

I should mention here that I probably should have gone with a piece of 1 1/2” wide flat stock, but I didn’t have any on hand. The 1 1/4” wide stock works just fine – I just need to make sure that I hold the tailstock firmly in place while I’m tightening the mounting nuts. With that sorted, I moved on to the next modification.


Ever since getting the rotary axis kit, I’ve wanted to add touch plate functionality to it. Guessing on where the tip of the bit was in relation to the center of the stock was marginal at best, and completely off at worst. This is especially true if I needed to do a bit change.

Touch plate for Rotary Axis My idea for a rotary axis touch plate

I got into SketchUp and drew out a couple of ideas for touch plates that could be put into the chuck, leveled, then used like any other touch plate could be. I even showed screen captures to a couple of friends, and they thought it was a good idea. Then one day, while out in the shed, I spotted my Triple Edge Finder from The Maker’s Guide. Something clicked in my brain, and I realized that I didn’t have to make anything, as I already had everything I needed.

In the video, I show you the process I used to set up the Triple Edge Finder for use with my rotary axis. I go into detail about how I figured out which touch plate thickness to use, how I modified the touch plate script, then how I edited the script in Mach3 to program the Auto Tool Zero button in the Program Run screen. I also give you a link to the source of that script.

Zeroing Z with the TEF Using the Triple Edge Finder on the headstock housing to set Z zero

The main thing to remember when modifying the script is to ensure the retract height in the script is set higher than the thickness of the touch plate in order to prevent damage to the CNC.


summing up

In a nutshell, that’s about it. I’ll not go further into it here. It’s better to watch it in the video than to try to type it out here. Suffice to say, I’m very happy with the result. Between the modified mount and the touch plate, I no longer have to use my machinist’s scale to mount a piece of material into the chuck of the rotary axis. I can now just find the center of the material with my center finder (link below,) put the material in the jaws of the chuck, line up the tailstock with the center of the crosshairs, and tighten everything down.

Here’s a link to The Maker’s Guide, where you can check out the Triple Edge Finder for yourself. I really love this tool!


Here’s a link to Dave Gatton’s website, where you can get info on a Gatton CNC kit of your own.


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Until next time, take care and have fun!