Cincinnati Shaper

[dallen]

I'm starting to think that the hardest part of making one of these scopes is going to be finding the lenses.

the lenses that were gave to me with the parts I can't make owrk no matter how I mix or match them.

[Jammer]

Here are some lenses. https://www.sciplus.com/s/c_17/sf_217

[dallen]

I found some at Edmond optics, now if could just make the damn things focus

[Jammer]

That's the part I don't understand. Focal length, negative meniscus, convex, concave...

[dallen]

from the little bit of info that I've been able to find, making one isn't as easy as some people let on to build.

I think a 24 inch reflector tele would be easier to build.

Anyway I spent another 18 dollars buying a 3/4" X 40 tap so that I don't have to do a bunch of internal threading while making the body parts. It should be here next week some time.

[dallen]

worked on this little part yesterday as can be seen from the photo one of them isn't in too good a shape.

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[cae2100]

looks good, are you going to harden it like the original probably was?

[dallen]

the original actually looks like it was made out of cast iron. no faster than it can be turned I doubt that it needs to be hardened. After doing sone thinking and looking at the original the area that engages the ring gear actually needs to be made larger in diameter so that the teeth will engage deeper. But i doubt that I will put that much energy into the thing, although it would be a nice exercise to do, but to do it right I would have to find the right size involute gear cutter to cut the teeth with.

[cae2100]

what pitch is it and why not make a cutter like this?
https://www.youtube.com/watch?v=bQXW5DP4ZSc

As it is rotated around, it'll cut on the part of 3 of the teeth just slightly, most of the material being eaten on the middle one while the other two just cut the relief angles on the gear. Then you can just make one gear cutter for a DP and can do the full range of gears using that same cutter.

I was thinking of doing something similar, but using something like a comb that attaches to a cutting tool for the shaper, then I can cut the gears using the shaper by indexing the teeth around rather than doing one tooth and filing the relief angles in.

[dallen]

the teeth are actually not that had to cut even if a guy was to use a homemade circular cutter. To make a hob like what the guy used in the video is a lot of work.

plus it probably wouldn't work on these pinions cause they are only like 31/32" on the main part of the thing which would make hob engagement pretty sketchy I would think. the deeper that the hob got into the part the more it would be eating into the side of the adjacent teeth.

if you grind the proper profile you should be able to cut gear teeth on your shaper without any problems. hard part is getting the cutter shaped correctly.