"centering microscope"

[cdegroot]

With the collet in the spindle still, I assume? In that case, doesn't it want to move?

 

[cdegroot]

I guess I accidentally cut a decent Morse taper, so I drilled and reamed the collet holder right in the headstock and it stayed in place (of course, it helps that it was in a soft metal). That hole should be absolute dead center. The collets themselves - hopefully this weekend - I'm planning to do in the four jaw for the rear hole and thread, but the final opening in the front will be done with the collet in the holder in the headstock. I'm gonna do a large one first to fine tune things, 2mm or so, then work my way down to watchmaking levels

I'll post pics and dimensions once I have something resembling success (no measurable run-out on the straightest rod I can find).

 

[ppod-]

With the collet in the spindle still, I assume? In that case, doesn't it want to move?

You need to prevent the spindle from rotating, sure. I stuck a "tommy bar" into its hole and was going to fix it to something (or just stick something like a wooden wedge behind it) but it turns out that a small screw that holds the front spindle cover protrudes _just_ far enough to wedge the tommy bar in its screw slot. Since the bar is slightly forced away from the spindle, it doesn't seem to wobble (and it'd take non-minor wobble in the spindle to notice in a 1.2mm screwhead).

 

[ppod-]

I guess I accidentally cut a decent Morse taper, so I drilled and reamed the collet holder right in the headstock and it stayed in place (of course, it helps that it was in a soft metal). That hole should be absolute dead center. The collets themselves - hopefully this weekend - I'm planning to do in the four jaw for the rear hole and thread, but the final opening in the front will be done with the collet in the holder in the headstock. I'm gonna do a large one first to fine tune things, 2mm or so, then work my way down to watchmaking levels

I'll post pics and dimensions once I have something resembling success (no measurable run-out on the straightest rod I can find).

Very best of luck! 2mm scale would already be very useful for watchmaking. I think barrel arbors are of about this size.