The collet fixture was designed to be mounted on the surface of the rotary table or the mill table. A knurled ring allows 8.0 mm collets to be pulled into the taper and closed without the use of a drawbolt from the back. This is particularly useful for clockmakers for gearcutting on a gear blank that has a pinion shaft attached that can be held in a collet. A bushing is provided that fits into the center hole of the rotary table and helps center the fixture on center. T-nuts and attaching screws are also provided for clamping the fixture in place in the rotary table or mill table T-slots.
WW or 8.0 mm collets vary somewhat in size depending on manufacturer. This adapter holds those collets made by manufacturers other than Sherline who produce a collet with a .314-.315 body size and .275-40 thread, which we refer to as 8.0 mm collets. Other common “WW” collets including those manufactured by Sherline have a body size of .312-.313 which we refer to as WW collets. A fixture for these collets is available as P/N 1164. It looks identical except that it has no identifying groove machined around the body. If you are using a brand of collets other than Sherline, measure the body diameter with a micrometer before deciding which collet fixture to order. If you are using Sherline collets, order the P/N 1164 fixture.