I'm making a table with round, tapered legs. I'm not a very good turner, and the tapers on these legs need to be dead straight, so I was pretty sure I would struggle to do that. I have a friend who could turn them in his sleep, but I like to do things for myself, regardless if it takes longer, so .... I decided to see if I could do it on my CNC.

I don't have a 4th axis on my CNC. OK, I'll make a simple jig and to turn the legs with a cordless drill. That was easy enough. A dowel in the end of the leg and a piece of 3/8" all thread at the head for the drill to turn. I thought I was on easy street until I found out I didn't have enough height available on the Z axis to cut the tapers from the top. Then I realized I didn't have enough reach from the Z-axis to the centerline of the legs anyway, so I had to make the cut along the side of the leg using a pocket cut. I hope that makes sense.


Cutting with the side of the bit gives a much rougher cut than using the end of the bit, but it was the only method available to me with the height limitation I have, unless I removed the spoilboard and raised the Z-axis mount up higher, and I wasn't going to do that. The good news was it sanded out beautifully and I have my nice, clean, straight tapers.






I really smoked the end of the leg against the jig from unnecessarily pushing on the drill.

It took a couple of hours to build the jig and figure out how to make the cut, and almost an hour to machine it with the very conservative toolpath parameters I used. My friend could turn one in less than 10 minutes. But I did it myself.

One down, three to go.

John