[rdsi]

Could rdsi show a picture of how he mounted his HS spindle to the main spindle?

Here you go ...

Attachment 415350Attachment 415352

The attached zip file contains my CAD drawing (MillMount.stp). I use Rhino 3D & can upload just about any format if you need something different.
The bolt holes are for a M8 X 1.25mm X 45 mm Socket Head Screw, McMaster-Carr 91502A201 - something I had laying around.
As I recall I cut the profile, holes and milled the threads on the 1100, then I finished up the large holes & slit the ends on my manual mill. The big holes I finished off with a boring head to get them round, parallel, and perpendicular, before slitting the ends - something the Tormach is not very good at or at least my manual mill is better at.

[kstrauss]

Thanks! That is about what I had planned but was concerned that additional support might be necessary. My spindle is somewhat smaller than yours so no reason to bother converting; I can easily redraw.