more basic the better. Have some ideas (mance prolly had them first), but places like powerflex/energy won't cannibalize kits. also most places won't sell parts by measurements or even "close enough" measurements.

maybe even solid tubes or blank blocks if there is no other way. I'll fire some tools then..

 

I don't have a #2 but these bits work on thin plastic and plexiglas.

 

It also cannot be machined for the same reason. It simply moves away from the cutting tool. A drill bit will penetrate urethane but when you remove the drill bit the hole (which is more like a "knife-cut" the width of the drill bit width) closes back up behind it after withdrawing. You can drill urethane epoxies that get glass-hard but then you wont find any suspension components made from urethane that are in that hardness range because they're too brittle and will crumble/crack when resisting/opposing load deflections.

Only way to shape/cut resiliant/compliant urethanes is by high-speed grinding with stones and/or abrasive media and high-speed. Much higher speeds than can be attained with electric/cordless drills. Small work can be done with a Dremel tool but larger work should be handled with Foredom type machines or pneumatic/electric die grinders that operate in the 15,000-25,000 RPM range.

You have to work very slowly removing small amounts of urethane at a time. The urethane must remain a powder/dust consistency when being ground off. If you work to fast or hard against the material it melts and loads up your grinding media. Once melted the abrasive tool loads up with molten urethane the abrasive tool is ruined. The lower modulus compounds are typically machined by knifing, grinding and sanding. In some cases, however, they can be worked like higher modulus materials by "freezing" them with dry ice or liquid nitrogen. While dry ice will oft-times suffice liquid nitrogen is generally too sverely cold and will result in fracturing the part.

If the lower modulus urethanes were easily machineable you'd find more urethane sold like aluminum, steel and Delrin stock, ie; in rods, tubes, bars and blocks for machining.

 

^^^Biggest proposer of answering ones question, exactly....*cough, cough*

 

how bout a tiny hole saw?

 

i know, got the tools.

 

Polyurethane bits meaning pieces of polyurethane, not drill bits, is what I think he meant.

 

to simplify, i'm looking for chunks of this stuff, blocks or discs of polyurethane

 

Not sure what you need. I generally go there to find odd pieces that I can't get at home depot.