Does it really need to be 5" long? If you cut it in half it would make subsequent machining a lot easier and also more practical in use when holding your collet block vertically. Also what is the A/F of your hex stock?

Chris just to be sure are you asking about the Sherline collet adaptor for 8mm or WW type collets or an 8mm MT1 collet

Edited By JasonB on 08/08/2020 18:15:00

My thoughts

1. Aluminium will soon dent and ding so not an ideal surface to be indexing against especially once you have been rubbing it about on stray abrasive from your sander.

2. Aluminium may gall resulting in the adaptor sticking and the drawbar roughing up the end unless additional washers are used.

For these two reasons I would go with steel.

3. Why add the added possible runout of an adaptor when you could machine a socket to take the WW collets directly, these need both taper and parallel surfaces. Much smaller hole required so more Sherline friendly

4. As the WW collets have an external thread how will a bolt work to tighten them, you need a drawbar with a female thread or ideally a draw tube so you can hold long lengths of pivot wire etc which is better than holding stub ends.

This thread may be useful, just make them longer and use a drawtube rather than nut

If you still want to go down the aluminium/ MT1 route then just bore it out parallel and Loctite in one of these.

Edited By JasonB on 08/08/2020 19:41:06

Giving it a bit mor ethought and bearing in mind the small scale work Chris want to do eg clock making/repair and the general small size of his machines I think I would go for something like this.

Square and hex collet block to take the WW collets directly which could be 16mm A/F and length to leave the collet's thread exposed at the back much like Phil's 10mm collet blocks.

For hand held use the "draw tube" can take the form of a handle, if made the same dia as the block's A/F it will not cause the block to tilt when resting on the sander table etc and can also be used as a nice hand vice. A nut can also be made which would be less cumbersome if the blocks were being held in the milling vice and a larger diameter one could also be made to act as a stop much like this Levin one.

keeping the actual blocks separate will make them easier to machine on the Sherline and you don't need as much material if the handle and nuts are interchangable.

Edited By JasonB on 08/08/2020 20:26:06

Just use them and make a longer handle for the drawbar if you are worried about getting fingers too close to sander.