Urethane cutter angles?

I've done just a bit with high-durometer urethane tubes, and I must say that abrasive machining works best for me.

I did try LN2, and a bit raked for acrylic. It worked fine. But freezing the stuff and keeping it frozen during machining is a pain in the patoozey.

LLoyd

If the urethane is really soft, you may have to build a fixture(a piece of tubing to match the od of the buching) to hold the bushings, with an end plate that you can compress the bush a bit will help as well. I would suggest a polished high positive rake carbide insert cutter(usually used for finish turning aluminum) If they are relatively hard, you could pop it in the freezer overnight to see if it hardens up a bit more and then bore it with above mentioned tool.

A highly polished HSS cutter with a sharp rake on it iwll do the job nicely. Slow feeds and high speed should do it just fine. The biggest problem is the abrasiveness of the stuff which will dull the cutter quickly. If you can get a real sharp carbide cutter, that will also work but you need knife sharp cutters.

-- Yeppie, Bush is such an idiot that He usually outwits everybody else. How dumb!

How about strapping a dremel to the toolpost? --Glenn Lyford

Think knife edge , that's the only way I got it to cut . Had some drive rollers for a woodworking powerfeeder , too deep on the back side . The aluminum hub was easy , the urethane needed a different approach . Is yer butt sore from that 1100 mile weekend ?

In the screen printing trade the squeegees used are urethane of various durometers. Somewhere between 55-85 shore is preferred. For fine details the edges must be very sharp and smooth. I have never looked at one under magnification but a trained finger can tell the difference between dull and just right. Sharpening is usually done by abrasive wheel. Diamond wheels sold for stained glass shaping work well and I have even used a tablesaw to slice off just a bit of the rubber. Somebody a few years ago came up with a machine that used the injector type razor blades, heated, to slice off a few thousandths. So a heated razor blade will shave this stuff. A hot wire might work also OUTDOORS for ventilation.

I do have some air die grinders and some abrasive rolls used for porting cyl heads. I have only 8 to do, 1.5inches deep so bringing the holes from 5/8 to

1 inch the mess shouldn't be bad, i just hate to get abrasives all over the lathe.

Not really. Got a 76 Goldwing with a real thick sheepskin on the seat. I left LA (Asuza canyon) at 7 AM yesterday and came up 395, then soaked for an hour in the hotspring at Bridgeport before riding over the Sierras in the dark and home by 9:30. A 550 mile day isn't bad.

1100 miles is a day's trip, not a weekend if you're really on the go. Used to do that kind of milage on a 450 Suzuki twin.

-- Yeppie, Bush is such an idiot that He usually outwits everybody else. How dumb!

I usetacould too , 30something years ago . I've learned to slow down a bit and enjoy ... though I have considered doing an ironbutt run on the Bag Lady , she's definitely built for it . Metal content , I'm havin' a ball building little custom bits for my bike and those of friends . Just finished turning a set of 304 SS axle caps for a bud that gave me a donor tranny for the '76 FLH . His is a Shovelhead too .

Piece of cake. i used hi-rake boring bit i had made for Delrin, it's not pretty, about the same finish if ground with a sander, but it will do the job. It only took

10minutes to do 8 of them with a collet chuck.