- This collet chuck is made from 1 solid piece of wood with a dovetail tenon to mount in a scroll cuck. The procedure to make one is turn round between centers and form the dove tail tenon at the optimal diameter for your chuck. Next mount in your chuck and bore a 3/4 to 1" hole all the way through to allow finials to extend back into the spindle bore. Next determine the form you will be gripping and turn the inside accordingly (for globes similar to the one shown the large diameter should be slightly back from the leading edge to positively grip the piece). The saw cuts can be made by setting a flat top tool rest near center, then with the indexing pin in place use a stiff back saw sliding on the tool rest to make the cuts. ( to get 8 segments equals 4 cuts on 4 index positions). The final step is to add the hose clamp and tape down the tail. The disadvantage of this type is that the work piece will be pulled slightly off center when the hose clamp is tightened.
- This collet chuck will use the self centering features of your scroll chuck. The optimal diameter of the dovetail tenon on my chuck is 4.06" (4 1/16th") so I cut a 37" long piece of white oak to 2 1/4" square then cut it in half and glued side to side with craft paper between and when that was set up cut it in half again then glued the halves together being sure that the glue lines/paper meet in the center. The resulting 4 1/2" square block is then mounted between centers with the junction of the 4 pieces as the center point and turned round to about 4 3/8" diameter. The dove tail tenon is carefully cut such that the bottom or end nearest the head stock is in full contact with the jaws as is the outer edge of the jaws ( this is necessary because the wood jaws will be bolted thru the steel jaws). The entire block is then mounted in the scroll chuck, marked for the desired length then parted off and squared off. The next step is to bore the center out and cut the internal form as required. The next step is to remove the piece form the chuck and one steel jaw to use as a boring guide to bore the holes for the mounting bolts. The steel jaw should be positioned on the dove tail end so that the seams are equal distance from each edge then using a drill press and a 15/64th drill bit bore the holes and repeat on all 4 segments. The outer ring cap screws could go all of the way thru or counter bored as I did and it should be obvious that the original flat head screws will not work. The jaws can easily be separated then cleaned up / trimmed on a disk sander. The inside contour can be changed if needed by installing the wood worm screw and tightening the jaws.