"Recycling" a lathe chuck key

[craig9]

Hey Garage Nut,

Thanks for asking. I think you're referring to the collet block. That's a device which is often available with 4 or 6 sides, which give you some good ways to get to 2, 3, 4 or 6 sides of a part. This particular one is an unusual one (12 sides) and comes from M&G Productions (in Melbourne, I believe), and was invented by an Aussie.

To use the collet block, you need a set of collets, and they're the expensive component. I've standardised on a particular external size of collet called ER-40 which suits my mill size. I use them for holding cutters in the mill spindle, and I use the collet block which you've seen, and I also intend to create a collet "chuck" which threads onto the spindle of my lathe, for workholding.

Hope this is helpful. Not sure where you're starting from, so I hope I'm not teaching you how to suck eggs. If you want more info though, please ask - I am always happy to explain.

There are lots of ways to skin a cat though. You could mill one flat, with the part held in a v-block, then use a square off the mill table to index round to the next flat and so on. Hope that makes sense too.

Also - apologies, I keep forgetting to add the cutter type, and RPM and so on. Folks have thanked me before when I've included this, but that slipped my mind until you mentioned it. I'll do what I can to include some detail in future to help out. For now, I will add a note below to explain what I did.

All the work on the lathe was done at either 500rpm or 800rpm (I forget which, but either would work fine, and the faster would would work better). For turning the cross-drilled boss down, to fit in the back of the collet chuck, I used a CCMT cemented carbide insert in a 12x12mm right hand holder. The end mill I used in the mill to trim the length down, and create the flat driving faces was a 10 or 12mm carbide four-flute endmill ran at about 1000 rpm. The radius/cove I turned with a home-ground 1/2" HSS bit shaped to approximately a 1/2" diameter. I went back to the CCMT insert to take the corners off the square, and also to produce the chamfer on the end. Chamfer tool would be better but I haven't made one up yet.

Cheers,
Craig