10 Sector Hard sectored disks.

[Tony Duell]

>  I've made just such a jig. I started with the frame of a SA400
> that I picked up scrap. I then made two blocks of aluminum

Thinking about it, the advantage of the SA400 is that the upper part of 
the index sensor, and thus the upper die block after modification, is on 
the clamp arm. Taht means the 2 die blocks are moved apart when you 
insert a disk.

The disandvantage of the SA400 is that because the 2 die blocks would 
move apart, they may not align again perfectly. And the other prolem is 
that the doors tend to reak if your'e not careful.

>  I used drilled detents on the flywheel, using a 10 hard sectored
> disk to index with.

Having got a proper dviding head (!), it would be very easy for me to 
either drill holes or mill notches in the pulley.

-tony