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hEADSTOCK iNDEXER

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I needed a simple way to index my headstock for a chambering fixture I was building. I also wanted it out of the way so I could leave it in place and just use it when I needed it. Chain sprockets provided the answer. They're cheap and nearly any tooth count from 10 to 72 is available. I bought a 72 and a 50. They cover just about
anything I would need

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Comments

If you modify the "stop" with a hole that the sprocket tips fits into you will double the amount of index points you get from each sprocket measured between the peaks and or valley's.
I thought about that but my "stop" is a pin machined to precisely match the radius of the root between the teeth. A hole would affect the fit with the sprocket. I could mount another pin some 1/2 tooth interval from the original pin and maybe I will if I ever need more than 72 divisions. Thanks.
 
Variation on the saw blade method, but with more options for tooth count. Very cool adaptation of stuff laying around to make the tools work for you. Will have to remember this trick.
 
If you make the stop pin like this, it will give you 5 degrees on the 72-tooth sprocket. The outside V is a snug fit inside the teeth and the notch hugs the tips of the teeth. By adding a lever-operated disk brake caliper, you could lock your spindle very firmly.On my simple rotary table, the twin indexers also act as the brake.
P9130053a.jpg
 
If you make the stop pin like this, it will give you 5 degrees on the 72-tooth sprocket. The outside V is a snug fit inside the teeth and the notch hugs the tips of the teeth. By adding a lever-operated disk brake caliper, you could lock your spindle very firmly.On my simple rotary table, the twin indexers also act as the brake.
View attachment 285693
Thats a perfect iteration of what was in my mind eye that would solve the problem with repeatedly while increasing the amount of adjustment at your finger tips.


I know doubling a 72 tooth segmentation gears output ability sounds "unnecessary" but when you consider there are many smaller sized sprockets that could be used to help make things easier and having the option to increase indexing stop points could prove very useful in the future.

With that said , the route you took looks to be s very easy yet effective method that solved the problem. If you wouldn't mind could you share the way you actually lock the dividing plate into the outside end of the spindle please? By just looking at it it would appear that you becau have used a concrete "wedge locking stud" into the headstock through hole rock is held in place with friction but i would like to be sure as i think i will fo this route on my 1940's clausing mk111 lathe as it seems to be very effective yet cheap and v ready to accomplish so Thank you very much for sharing and any additional info ypu should provide would be greatly appreciated.

Thank You
 
If you make the stop pin like this, it will give you 5 degrees on the 72-tooth sprocket. The outside V is a snug fit inside the teeth and the notch hugs the tips of the teeth. By adding a lever-operated disk brake caliper, you could lock your spindle very firmly.On my simple rotary table, the twin indexers also act as the brake.
View attachment 285693
That dual function stop is a good idea that I'll keep in mind if I need more divisions. I thought about a brake but my indexer is driven by a threaded rod and the stop is so solid it already is a spindle lock. The 72 tooth sprocket offer lots of combinations. I'm a big fan of 20 tpi for my fixtures and gizmos because each complete turn is .050 inches and the 50 tooth sprocket allows me to calibrate my stuff with .001 " divisions. It also allows me to make 5 lug hubs. The variety of tooth counts in the various sprockets and chain pitches is awesome, AND they're cheap.
 
I used two support posts to hold a pair of those stop pins. The flat on the end presses down on the sprocket when the SHCSs are tightened.
P9130054a.jpg
P9130057a.jpg
 
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