Here is a rotary fixture table that I made to hold both the harmonic drive and the tail-stock.

It is not really meant for any particular purpose, its just so I can easily connect it to my machine when I need to work on the rotary. There are several other fixtures that I will be making, but for now I will show you how I made this one.

The Design

The table is the basic shape I discussed in my CNC table section.

CNC Tables

Its the same layout except I used a overhang that is about 2-5/8” which makes it 4-5/8” from the first table mounting bolts. Note that the mounting holes are all 5/8” from the edge. These mounting holes are 3/8” in diameter.

Next I added the six main harmonic drive mounting holes. The holes are all 11/32”. This is important because I am going to insert some 1/4-20 rivnuts later.

Next I added a series of holes so I could mount the tail-stock in several positions. Again these are 11/32” holes for the 1/4-20 rivnuts.

Here is what the fixture looks like once the holes are drilled.

Adding the Rivnuts 

I flip the board over and lay it on my workbench. I will be working from the bottom of the fixture table.

I am going to be using some clear Gorilla glue to add a little more strength to the nut, so I use a cotton swab to moisten the inside of each hole.

I place a 5/16” plain washer over the hole.

You can pick up some rivnuts here:

1/4-20 Rivnuts

After adding a couple drops of glue to the nut I set it in place.

I tap it into place with a hammer.

Here is the bottom of the fixture table with all the rivnuts installed. Note that I only work on four or five nuts at a time so that the water does not dry out.

Mount the Table

I reinstall the table. I added a washer and 1/4-20 x 1” bolt to each nut and snug them up. This is done to make sure the Rivnuts are tight against the table while the glue cures.

Mounting the Rotary

You can use some 1/4-20 x 1” hex bolts to hold the rotary and tail-stock in place.

Here, I am using some 1/4-20 studs, and small knobs to hold both the tail-stock in place.

1/4-20 Studs

Small Knobs

That’s it, the fixture is complete. I will be working a couple alignment jigs that I will post once they are completed.

While this fixture is not a practical one its great for getting the rotary setup and doing some basic operation.

An alternative would be to mount the tail-stock and rotary drive on their own separate fixtures. This would allow you to work on large pieces.

Note while I am mounting this fixture to one of my CNC Construction Set machines, the fixture can also be easily mounted on the KRMx02 with a couple added mounting holes. That said, I will be doing a write-up on mounting directly to an 8020 series 10, 1030 extruded top very soon.