Keyway cutting

If you have a vertical mill you can use a tool in the spindle similar to the lathe setup described earlier. All you need to do to the mill is devise a way to lock the spindle from rotating. Drilling or milling out as much material as possible before slotting is highly desirable.

For smallish jobs, College Engineering Supplies used to sell a casting (complete with drawings) to make a hand operated slotting tool to the design of the late Peter Robinson of the Peterborough Society of Model Engineers. It was meant for use on a Myford ML7 but, with a riser block, it is used occasionally on my larger lathe.

Once needing to made a unique adaptor for a speedo drive, the 1/8" toolbit was held in the Tailstock, and the barrel racked to and fro to take out the corners of the pre drilled hole. It was a slow job, but the end result did what was required of it, so worth it.

Howard

Edited By Howard Lewis on 25/01/2019 18:32:36

I cut my first keyway recently using the mill and a piece of HSS tool steel, it worked fine and was easy and quick to do. See Jasons post above, it was after he showed me the method on the lathe that I gave it a try. I went with the mill as I suspected it would work as it does with the lathe. I found that the diagonal of the 4mm tool steel gripped nicely in a 6mm collet which made life easy. I also removed the bulk of the material with a 4mm cutter which just left the tool to square it out. I have a 3mm keyway to cut but not having a suitable size collet I thought of making a slotted sleeve to suit the tool diagonal and use a larger collet. I have also made a spindle lock from bits out of the odds box, works fine.

Made up a sleeve to hold the 3mm tool and to fit a 10mm collet. I didnt machine out any material as I did with the previous 4mm keyway, just went with .001" cuts and it worked fine. Sixty cuts for the 1.5mm depth but it is really quite quick to do, I set the column head stop for the length of stroke which makes life easy.

I have only cut aluminium and small keyways so far, so dont know how it would cope with steel and larger keyways.