That knurler (the one TomG posted in his first pictures) is far superior to any scissor type because of the inherent rigidity of the opposing knurls in a solid frame.
I used to use a knurler in CNC machines that would remind you of the Aloris one posted by petertha, though it was far sturdier. It had two opposing slides that slid in & out on dovetails with a common LH/RH threaded screw. The "carrier" that held the roller assemblies had float up & down in the track for centering, but bolted solid once you had it in place. It was a robust tool, and it's bulk was more vertical than horizontal. On CNC lathes with limited Z axis travel, this was important.
Like the Aloris shown, getting the rollers right over "top dead center" and bottom was the key to success. The one TomG shows is better in that the design puts the knurls right on center opposing each other perfect without any fuss. I might like to build something similar, though I'd like to make the knurl holding sliders out of a hex or 12-sided stock so I could index the knurls. This allows using straight knurls to cut (rather than press) a diamond knurl, cut straight knurls with left and right angles knurl wheels, or altered angle knurls with various settings.
(11-10-2012, 07:29 AM)stevec Wrote: Tom, Ed, I don't toke but do enjoy a few home brews.
The neat thing are the surprises the next morning when I read my own posts
Nice looking tool! I'm at a point of wanting a knurler myself. And I like this design a lot. I'm thinking I may try to make this design myself.
Thanks!
dalee
Yes Dalee, I think it would make for a fun project.
Here are a few pertinent dimensions:
The main frame is .75" x 2.50" x 6.00" with a 2.00" hole.
The locking screws are 5/16-24UNF x 1".
The feed screws are 5/16-25UNF x 1.50.
The knurl holders are .625" x .625" x 1.50" with a .249" hole .219 from the end. These need to be hardened steel.
The side frame pieces are 1.25"H x 1"W x 2.75"L
The end piece is .50" x 1.25" x 2.69" with a hole for a .500" shaft.
Everything is aluminum except for the knurl holders and the shaft.
The shaft on the back can be held in a drill chuck, for small knurls, or a turret. I normally just hold it in my tool post.
Mike: The easiest way is to use some O1 tool steel to make the holders. You might even be able to find some 5/8" square. Then, one the machining is finished, you just heat them up cherry red and quench them in oil. That will make them glass hard and likely to crack, so you can temper them by heating them with the torch just enough to burn the oil off.
Another and cheaper method is to make them out of mild steel and case harden afterward. Just heat them cherry red and dip in a case hardening compound (like Kasenit), then keep them red for a few minutes with the torch to give the carbon time to soak in, and water quench. No tempering is required because only the surface gets hard.
(11-10-2012, 04:28 PM)TomG Wrote: The shaft on the back can be held in a drill chuck, for small knurls, or a turret. I normally just hold it in my tool post.
Mike: The easiest way is to use some O1 tool steel to make the holders. You might even be able to find some 5/8" square. Then, one the machining is finished, you just heat them up cherry red and quench them in oil. That will make them glass hard and likely to crack, so you can temper them by heating them with the torch just enough to burn the oil off.
Another and cheaper method is to make them out of mild steel and case harden afterward. Just heat them cherry red and dip in a case hardening compound (like Kasenit), then keep them red for a few minutes with the torch to give the carbon time to soak in, and water quench. No tempering is required because only the surface gets hard.
Tom
Thanks, Tom. I just looked on Enco and MSC, and they have reamers at .2490, .2492, .2495, and .2498. Which would be best for the reamer pins, that are listed at .250? I have a 2-ton press.
If the parts were soft, I'd use a .249 reamer, but since they are hard I would go with a .2495. If they are still too tight after hardening, you may need to lap them out a bit.
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