[pzzamakr1980]

I am having some difficulty machining the softer urethanes (60A) that I use for bushings. The finish is terrible and tolerances aren't great either. I expect this stuff to move around a bit, and it can do so, but it moves too much and the tools I have been using just don't seem to work.

What tools and tricks do ya'll use. Thanks

[big_mak]

You're gonna have to use the sharpest tools possible.

If you are using carbide inserts, you will have to use some thing with a ground profile, and loads of coolant to keep that stuff from sticking to the tools.

[AbsoluteZero]

Sharp tools is the key. Use tools for aluminum, large positive rake. Depending on the coolant you are using an air blast might be more efficient.

[pzzamakr1980]

Thank you. Thats what I kinda figured. How well does HSS steel tooling work. I can get that very very sharp. Also, does this stuff harden when put in the freezer?

[AbsoluteZero]

HSS will work fine its not to abrasive just gummy. I would stay away from freezing, that will just cause more trouble. You'll think its working and then the temp will come up and you'll be at a lose. Start with sharp tools no nose radius and go from there.

[pzzamakr1980]

Awesome, thank you all.