10 Sector Hard sectored disks.

Hi 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 that would mount where the index hole was. I remove them both and mounted a disk in the flame. I then positioned it on the table of a drill press. I aligned the drill through the index hole where the two blocks would mount. I then clamped the frame to the drill press table. I then removed the disk and mounted the two blocks. I drilled the blocks at the aligned hole. I used a #93 drill. This seems to be close enough. I made a punch with the shank of the drill bit by grinding a groove across the end, leaving two sharp blades, like most punches have. I used drilled detents on the flywheel, using a 10 hard sectored disk to index with. I've not made the mechanical detent yet but will do that eventually. Right now I just have a visual pointer that I visually align with the hole. Another way would be to find a gear with teeth divisible by 20 ( 20, 40 or 60 would work ). One could the mount it to the flywheel and use it as a better detent. It is a slow way to make disk but works well enough. If one is concerned about how well the spacing is, a few minutes with an oscilloscope and a drive should be able to determine the quality of the hole positions. Dwight _________________________________________________________________ Peek-a-boo FREE Tricks & Treats for You! http://www.reallivemoms.com?ocid=TXT_TAGHM&loc=us