http://i389.photobucket.com/albums/o...ps96fe92fb.jpg

Yes, that makes sense. From the photo you can see it's a very simple slotting operation. I wouldn't be doing the tapered thread you see there. I haven't decided on four or six slits, so a hex or square rod would be enough for indexing. I still can't quite visualize the fixture involved, but perhaps it could be as simple as a bracket mounted to the compound which holds a square or hex block center-bored and threaded to accept the threads on the collet. That would be cheap enough!!!
Thanks