Group Project: Dividing Head - Organization and Design

I've been following along and need to comment on a couple of design features.

I suggest adding a second worm support (reddish part) on the other side of the spindle and extending the worm shaft so that the worm is not cantilevered as currently shown. I see that such a change will cover the existing angle engraving on the trunnion, but that engraving can be relocated to radial marking on the worm support. The gear mesh will be much more durable if you support the worm from both sides.

Also, I think I see two large jam nuts on the back of the spindle. Consider the hex size and how un-common wrenches will be. Instead of buying or fabing wrenches, I suggest using a single cylindrical nut (maybe knurled OD) with some blind holes for a pin and at least one threaded setscrew. Drop in a brass ball, to protect the spindle threads, before installing the set screw(s).
 
I had thought about the cantilevered worm gear. Since this is a dividing head and not a rotary table, the worm should never be driving against a load, it is just doing positioning There are locks for the worm shaft and the spindle and the trunion to clamp everything solid during a cut.

Sometimes I forget that not everyone has all the same tools as I do. I have wrenches that fit those nuts, most probably don't. I am already using brass tipped setscrews for the spindle indexing plate.
 
Flyinfool said:
I had thought about the cantilevered worm gear. Since this is a dividing head and not a rotary table, the worm should never be driving against a load, it is just doing positioning There are locks for the worm shaft and the spindle and the trunion to clamp everything solid during a cut.

Sometimes I forget that not everyone has all the same tools as I do. I have wrenches that fit those nuts, most probably don't. I am already using brass tipped setscrews for the spindle indexing plate.
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IMO, I'd probably prefer a knurled nut to use with a pin wrench (like 5c collet blocks use).
 
Gotcha. But, if we're talking about a hex wrench of a size that people are unlikely to have, how does a $30 wrench that will have exactly one use improve the situation?

How about the inner lock nut being replaced by a bearing washer, and then the spindle being turned down so that a 1" nut could be used. It could be an OTS nylock or a castle-nut. Everyone has an adjustable wrench that size. Don't they?


Right. Because the center has to open up for collets.
 
Shotgun said:
Gotcha. But, if we're talking about a hex wrench of a size that people are unlikely to have, how does a $30 wrench that will have exactly one use improve the situation?

How about the inner lock nut being replaced by a bearing washer, and then the spindle being turned down so that a 1" nut could be used. It could be an OTS nylock or a castle-nut. Everyone has an adjustable wrench that size. Don't they?


Right. Because the center has to open up for collets.
Click to expand...
Do we NOT have them? I would figure a 5c collet block set is so common that we'd all have one already.
 
I dont have one but if i needed one for this id get one. I am still tooling up and only have 1 5c collet tool that will use the collets.
 
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