When Santa brought me a 3D printer for Xmas little did I realise the can of worms that had been opened. The student magnetic accelerator project had been largely 3D printed. One thing led to another and eventually I convinced myself I needed a CNC mill to help me complete my Rail Gun project. The machining of the materials I had selected was rather messy and complex not to mention I didn’t know anyone that would do it for free or beer. After doing nowhere near enough research off to the Web we went and Ebay eventually came through with this Clarke CNC mill. 

The previous owner had fitted ball screws and stepper motors along with a basic Mach3 setup and it worked, well, mostly anyway. Collection ensued from London and after taking the top off the bottom and loading it into the car it was garage bound. It then spent a week or three on my bench as I striped and lubricated it and generally found out how it all worked, always the nosy one me.

Eventually I reassembled it on the bench and started playing. The main deficiency I experienced was a lack of tooling. It came with an old fashioned chuck with key setup, a legacy of its birth a long time ago no doubt. Updating this to collets and a decent chuck was easy enough except I had to make a new drawbar. The reason was the chuck thread was M10 and the rest of the world was M12. Never mind, simple enough. It was about this time I began thinking how easy this would be if I had a lathe – hold that thought.

Once I had some tooling and a vice I started playing again. The 3D printer was pressed into service as I made limit switches for all 3 axes and eventually a chip guard would take shape too. I just used the colour plastic I had in the printer at the time so red and yellow it was.

Once it was all up and running I thought it was about time I started making some chips. Some playing in Fusion360 soon brought me a test piece out and I loaded up the file. Initially I ran it a long way from the work piece and with the spindle off. All went well but the program would stop for some odd reason. The software was licensed and everything else looked good so off to Google for some inspiration. My initial thoughts were this was an old version of the software so I backed up the Mach3 directory and installed the latest version. This had two knock on effects, neither good. Firstly it did not fix the problem – darn it. Secondly, it erased all the setup info for the mill motors etc. Now nothing pretty much worked at all.

To cut a long story short it turned out the stopping was because the license was dodgy and buying a genuine one fixed that, yippee. Resetting all the mill parameters, motor tuning etc. was a tortuous process but I now know quite a lot about how to set up Mach3. It all appears to be working again with just some Fusion360 and tool size issues to sort out.

There was one fun instance when I was pretty much taking my first cut. My mistake was telling Fusion360 my ideal size of blank to cut the piece from. In reality it was correct on 3 sides just a lot longer on the 4th. The net effect was the feed rate and cut depth were far too great for the mill with the inevitable results. Whilst filming this I had my phone in one hand and the emergency stop in the other. Oh yes, that’s another valuable lesson, only have one emergency stop not two. If you listen to the video you can see when I stop the motion but it is a second or so until I get to the motor stop.

I am still tweaking this project with the aim of using it where necessary but the arrival of the Boxford machines has refocused me somewhat

This particular project has almost run its course and is almost ready to use.

9th October 2018: well, after making a few items on the mill it has reached the end of its life with me. The garage is now 90% insulated with only the floor to go. I am now reorganising my garage space to accommodate all the various machines and to separate out the wood working area from the metal and electronics area. The addition of a laser cutter has put even greater pressure on space and my complete lack of organisational abilities. So, with a heavy heart it has been sold on eBay and is being collected today. Amazingly it seems destined for a new life in Romania. I guess it has served its main purpose and that was my stumbling up the rather steep learning curve associated with CNC machining.