Attached are photos of an adapter that I made so that I could utilize a collett set on my Smithy three in one machine. The spindle is a MT4 and the collett set is MT3.
I cut a piece of 12-1.25 all-thread 0.625 inches long and then bored and threaded a hole 0.375 inches deep for a 6-32 thread. This was installed in the end of the collett holder.
I ground off approximately 3/16 inch off the end of the tang on a MT3-MT4 adapter to remove most of the hardened section. I then bored a 0.375 inch hole through the tang.
I bored and threaded a hole 0.375 inch deep for a 6-32 thread in the end of a piece of 3/8 inch all-thread that would act as the drawbar.
I cut the head off of a 6-32 socket head screw and glued it into the end of the drawbar with Locktite.
I made a stepped washer from a piece of 1 !/2 inch aluminum round stock to support the drawbar at the outside end of the spindle.
I installed this on my machine and tested it for concentricity by putting a 1/2 inch mill in a collett and checking it with a DTI. The runout was 0.0002.
I made the drawbar removable so that I could use a wedge to remove the collett holder from the adapter.
http://i1008.photobucket.com/albums/af204/capjak/Collett/th_Smithy004.jpg http://i1008.photobucket.com/albums/af204/capjak/Collett/th_Smithy002.jpg http://i1008.photobucket.com/albums/af204/capjak/Collett/th_Smithy003.jpg
