A Shop-Made 5C Collet Closer

I wanted to use 5C collets on my Colchester 13x24 "roundtop" but it didn't come with a collet closer. So I decided to try my hand at making one and the result is pictured above. The 5C adapter (center) was made from some 3.5" diameter 1018 stock while the L0 spindle nose protector (right) started out as a piece of 5" diameter 1018 stock, both of which were pulled from the scrap bin at the local steel supplier. The spindle nose protector also serves as an extractor for removing the adapter from the spindle bore. The drawtube was made from a piece of 1-3/8" O.D./0.120" wall DOM tubing and the handwheel was turned from 6x6x2" block of 6061 aluminum after first cutting it to an octagonal shape.
The main challenge, other than hogging down the stock to the rough dimensions, was cutting the required tapers. The lathe spindle has a #5 Morse taper so the 5C adapter needed that on the O.D. and a 10 degree taper on the I.D. to match the 5C collet. Also, the spindle nose protector needed a taper on its I.D. to match the L0 spindle nose. The tapers were all cut using the compound which was first set to the proper angle using dial indicator running on the center height of the tailstock ram.
Note that I also installed an indexing pin in the 5C adapter. I haven't seen this on any other collet adapters but I thought that it would enable repeatable positioning. The bore of the adapter was cut as the final operation to help ensure concentricity.
Another challenge was cutting the blind keyway on the I.D. of the spindle nose protector. This was done using a shaper after first drilling a hole through the piece at the innermost end of the keyway. The result can be seen in the picture to the left. After the keyway was cut a plug was pressed into the hole and it was tack welded. This operation was done before the finish cut on the O.D. of the spindle nose protector.
The component parts of the drawtube are shown in the next picture to the left. There are two bushings that center the drawtube in the lathe's spindle through hole. They are pressed onto the drawtube with a light interference fit and fit the through hole with a loose slip fit.
The remaining pieces are arranged in assembly order above the tube. The rightmost piece is a bushing that fits into the outboard end of the spindle. It is a slip fit on the O.D. of the tube. To the left of that is a needle thrust bearing and washers (INA TC2233 and Torrington TRB-2233, respectively). Next in line is the handwheel followed by the retaining nut.
This picture shows how the parts assemble on the tube with the handwheel omitted for better visibility.
This shot shows how the bearing bushing fits into the recess in the handwheel. The centering bushing's position near the bearing bushing serves to prevent the bearing from leaving the bearing bore when the drawtube is not in use.
Here is a closeup of the threads on the collet end of the drawtube. Since my lathe has a metric leadscrew and these threads are not, they were cut with the halfnuts constantly engaged. That is why there is a substantial relief groove beyond the threads - to give time to crank in the crossfeed and reverse the spindle at the end of a pass.

Also note that there is about 0.100" of relief on the outer end of the threads. This allows the collet to be drawn slightly inside of the tube if necessary and also helps to get the collet threads engaged when assembling.

Finally, here are some pictures with the drawtube assembly installed on the lathe.