Aluminum & Steel CNC control box construction

I’ve talked about projects for my neighbor’s lathe on this forum, but how about a project for my lathe? I’ve got an old classic manual Clausing lathe (late 1960’s?) sitting in the robot studio. A few years back I thought that it might be time to add some “bolt-on” CNC functionality to it, for the really repetitive jobs.

I wanted something quick and easy. Rather than just buying a control box, since I was really enjoying my journey with the AVIDcnc, I thought it would be reasonable to design the CNC control box I needed so that it took advantage of the AVIDcnc strengths.

For this project, I called up the guys at AVID, bought an extra seat of Mach to use to control the machine an extra ESS and some proximity sensors. I headed into the electronics lab, pulled out a pair of power supplies and a breakout board and I was well on my way.

ESS from AVID:

Proximity Sensor from AVID:

Wiring/crimping tools (1 of 4 different kinds of crimpers used in the project) and somewhat ugly temporary wiring from the breakout board, just to get some basic functionality up and running.

Once I had the components / connectors selected and had a good idea of how I wanted to arrange things in the control box, I took a few minutes to make some flat CAD. I didn’t even spend time to model in the components. I just drew in circles where the mounting points go, or where fasteners need to be placed, basically just the bare minimum needed to generate some G-Code. :slight_smile:

The design is such that everything will mount to a single central steel plate that can be removed and all wire entries/exits, to the enclosure, will use disconnects.

With that, it was time to make some sparks on the 1/2 of my AVIDcnc setup for plasma.

Looking at the image above reminds me that I really should start keeping a plastic lunch bag and a rubber band down there to throw over the end of the spindle while running the plasma side. Lots of muddy water splashing on it (even as high as it is retracted) probably won’t be great over the years and that would be so simple to put on / tack off that I just need to do it. (Yup, an afternoon chore for today)

In this photo a couple pieces fell out and sank into the tank and were retrieved.

And after a little quality time with the grinder to remove mill-scale and rust, you get the below. I use a different method now (not an angle grinder), but this was what I was doing back in the day…

Some of the pieces were folded / bent along designed in bending cuts. (This was before I had refined the plasma marking method to put down bend lines.)

After this I did a quick mock-up / test fit with all the components and verified spacing / fit with the base-plate and many of the electronics components. I had designed in the breakout adapter (upper left corner in the photo below) so that I could test with it all the way through, but before I finished, I went back and put in a propper wiring harness.

next up, I went back to the CAD system and drew a few simple representations for the outlines of the box side pannels and top/bottom. This was super simple since I had made the smaller interface / connector pannels in steel, above. And then it was back out to the AVIDcnc for some plasma cutting in aluminum.

1/4in thick aluminum side plates:

And then a quick mockup. In the corner I’m using 4-small lengths of 80/20. This is a nice snug fit on 1/4in aluminum, and the center hole is the correct size to tap for 1/4-20 so those locations will be used for the mounting of the top/bottom plates. This is an extremely simple way to make an enclosure. I first saw this method used for mounting acrylic panels in the trade-show industry, many years ago and I have adopted and used it in a handful of projects now.


And then it was back to the AVIDcnc for more plasma fun, to cut out the top and bottom panels. These pannels are cut from 1/8in thick material since they don’t need to be tapped for screw threads.

Aluminum just looks so very different when it cuts, compared to mild steel or even stainless.

And here we go, … A test fit. The parts line up well and fit snugly. I didn’t have any button head cap screws on hand so these socket head cap screws are just a temporary stand in. The same thing is done on the bottom, and in final installation, those screws will countersink right into the middle of the rubber feet for the control box, so that just the 8x screws hold the enclosure together.

I probably should have run these under the hose before taking this picture or doing some of the mock-up work. :rofl:

After that it was time to layer in the steel pieces from above. When I cut the aluminum side pannels I put a pierce right at the center where each of the mounting screws will go so, later, it was trivial to run that plate over to the drill press, chase those holes to the precise tapping size, throw in the Tapmatic and power tap them all in a matter of minutes. Using that method ensurs that since the same hole pattern was copied between the two parts in CAD, everything is going to identically line up with all those little screws.

And yes, these parts do not need anywhere near this many screws. It is an eclectic look that I enjoy.


Next up, it was time to protect that steel from rusting up over the years. Sure the robotics studio is temperature & humidity-controlled year round, but one never knows if work might move them across the contry again in 5yrs or some such. Here I am using a selenium dioxide (cold bluing) dip process with a dry sealant dip process. For this kind of part an oil finish does not make sense.

These parts came out great.

Some last assembly shots:

While building this I had figured I’d pop down the road and drop of the aluminum parts off for a quick ‘Type-2 Class-II’ anodize, but it has been a few years since I completed the project and somehow I still haven’t done that. :rofl: Oops!

In sharing this, it is not meant to be a suggestion of how you should build a control box. Rather, this is just an exploration of how I used the tools I had on hand to do what I did back in the day. Who knows, maybe someone will like seeing this project as much as I enjoy seeing the projects others have posted? :slight_smile:


That’s very nice work! The 8020 in the corners is a nice touch,

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Thank you Gordo! I was hoping that at least one person would see and enjoy some part of the project. :slight_smile: The projects that people share here are one of my favorite parts, I hope more makers will choose to share the projects they are working on.