Old man needs ideas or direction?

SG51Buss said:
An interesting challenge. How 'bout:

Run your stock thru a collet to a fixed stop position.

Have a custom made tapered tenon cutter (like a pencil sharpener) mounted in the tailstock.
Kinda like this. From: http://www.fine-tools.com/zapfenschneider.htm
View attachment 84290

This tapered tenon cutter would be advanced onto the stock, cutting the taper, and its inherent design (inner taper) would stabilize the shaft during the cut. The very front, non-cutting short section of the cutter's entry hole would have an ID slightly larger than your stock rod. Once the taper cut is made, the tool is left in this position so that the non-cutting entry hole will act as a steady rest on the end of your workpiece, stopping just shy of the first groove.

Then cut the grooves with the formtool. If stock is consistantly fed to a fixed stop position, the carriage can be locked down, for consistent/repeatable groove/formtool cuts.

Of course, use plenty of bacon grease during all this.


Mmmmmmmm, bacon...
Click to expand...

I recall one of the Tubal Cain videos shows him using a cutter like that for rounding ends. Not sure which one though.
 
i would try to cut all three grooves at the same time using a locked in place vice grip type arrangment with three point cutter on one jaw and a small ball bearing for resisting the cutting force on the other jaw. possibly the parting tool could be incorporated with it. deburring in a tumbler would be the last step. . taking any marks left by the bearing, off the related area. . . .
you do have an interesting project with these. there are so many different ways to skin the cat, so to speak. . . . .
let us know what your final idea is...................................
 
The pencil sharpener could have an extended hood that would act as a follow-rest backup.
 
GK1918 said:
no, I can't farm this out, area shops are Nasa minded dont want to be bothered
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I bet the NASA minded guys would go for it if they were told it was for playing cribage in space on the space station. 2000 pins? They wouldn't blink on why, that is how government projects roll. And probably $200 per pin. But very precise tolerances.
 
Could you make some sort of steady or traveling rest that's 2 sided to support the stock to use the form tool
 
I like the tenon cutter idea for the taper. For the rings, if the form tool is too much for the material, I'd sure look at a follow rest or something to steady the workpiece so the form tool will work. Another possibility would be to rig up a clamp type knurling tool with three straight rings and deform the metal to make the grooves. This might be real good for the copper pins since most copper machines poorly. After forming the grooves, there will be metal proud of the original OD. This could be removed or might be a desirable "feature" depending on how it looks. WRT the copper, there is a copper alloy that machines nicely. I cannot recall the alloy number but it is "tellurium" copper and is the stuff they use for making welding nozzles and other copper turnings. Machines very well in my experience. Most of the other copper alloys that I have tried are hard to machine. For as many pieces as you have to make, a day or two figuring out a decent process will pay off in the long run.
 
All good and workable ideas guys. As far as copper, thats out- no way, customer provided material. Soon as it gets kissed it bends like a pretzel.
Yes Ed T spending little time with a process I always do, but for this job comes down to time turning the taper and for any type of rest I have no room.
oh well such is life
sam
 
Had another idea for your tapers, was going to mock-up an example in wood, but didn't have the time.
So, I'll struggle to explain.

Imagine taking a block or plate, say 1/2" thick, 2" x 4" rectangle, and drill a 1/4" hole (I assume that's your stock size) thru an edge, centered on the thickness and one of the 2" sides, about 1 3/4" deep. Kinda like making the hinge pin hole in a hinge plate. This will be a guide for sanding the taper of the round stock.

Now, cut off the corner opposite the entry hole, at your 5° angle, such that the exposed portion of an inserted rod is the stuff you want to remove to make the taper. The bottom of the hole will act as a stop.

Then, clamp this gadget to the table of a disc sander, aligning the 5° cut against the sandpaper. Again, think 'pencil sharpener'.

To use, chuck up a rod into a power drill, run it reverse (opposite the sanding disc rotation) into the hole, and the disc sander will grind off the rod to your taper, and the rod will stop at the hole bottom. (Assuming nothing gets clogged-up here).

If your rod stock is 3' long, do this to a bunch of rods as preparation. Then move them to your lathe for the second operation (grooving and cutoff).

Lather, rinse, repeat...
 
Good idea Steve "I got the idea". I'll fiddle with that even if I get rid of 90% taper then finish. Like I say the biggie is I can't take a healthy cut 'taper".
Even .002 is already boarder line. My poor compound gona get worn out on this job.

thanks sam
 
Steve,
I thimk it shows a lot of inventiveness and willingness to learn when you take on a project such as the one you have going now. Just keep making one part at a time and before you realize it you will have all the parts made and can move on to final assembly and buffing. Good luck and you might try a rubber cushioned floor mat to reduce back fatigue. HF sells them and they work wonders if your standing in one place for extended periods of time.

Bob
 
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