I bought a small Vicmark VL120 wood lathe chuck to fit a Vicmark VL300 lathe that I am working on, the chuck came with a standard set of jaws which close up to approx., 50mm diameter.
So I wanted a smaller set which would grab smaller pieces of wood. Got a piece of 1040 or 1041 round and machined it down to shape to fit inside the existing jaw set. The internal jaws of the standard set are angled about 10 degrees so machined the out side with that angle to help grip these and then drilled out a 6mm hole to fit a longer screw to hold them in place and then drilled a 13mm hole about 17mm off the bottom. That way I could use a shorter screw.
Not sure of the exact number of the steel but it sure was tough, ended up using solid tungsten carbide drills. I must have resharpened my standard drill bits about 8 times before that. Should have stuck to plain old mild steel as I probably have dulled my band saw blade.
Took a while to cut it up on the band-saw into quarters and fitted it to the chuck, it will close down to 17mm and it will open up quite wide but then the radius changes the wider it opens up and the edges really dig in.
So I wanted a smaller set which would grab smaller pieces of wood. Got a piece of 1040 or 1041 round and machined it down to shape to fit inside the existing jaw set. The internal jaws of the standard set are angled about 10 degrees so machined the out side with that angle to help grip these and then drilled out a 6mm hole to fit a longer screw to hold them in place and then drilled a 13mm hole about 17mm off the bottom. That way I could use a shorter screw.
Not sure of the exact number of the steel but it sure was tough, ended up using solid tungsten carbide drills. I must have resharpened my standard drill bits about 8 times before that. Should have stuck to plain old mild steel as I probably have dulled my band saw blade.
Took a while to cut it up on the band-saw into quarters and fitted it to the chuck, it will close down to 17mm and it will open up quite wide but then the radius changes the wider it opens up and the edges really dig in.