"Machinable" plastic

[USMCDOC]

i get all my aluminum at the scrape house.. heck i can get plates of copper..

 

[jwink]

I use UHMP (Ultra High Molecular Plastic) one of the cheaper plastics, dimensionally a bit more stabile than Delrin, doesn't like real high spindle speeds though, using coolant helps a lot.

 

[Fast14riot]

I use UHMP (Ultra High Molecular Plastic) one of the cheaper plastics, dimensionally a bit more stabile than Delrin, doesn't like real high spindle speeds though, using coolant helps a lot.

HDPE, VHMW, UHMW, Pom-C are all the same family of plastics, just higher densities. HDPE is a good alternative with free machining characteristics and a much lower price point.

 

[Geno C]

I usually use wood. There’s is some chip out sometimes like this but it’ll get you close enough.

I am learning that lower grade aluminum may be cheaper.... The "crashing" mentioned above is a concern too. I've also considered wood; which may be what I end up using. Thanks for all of the replies!

 

[Joe Maisto]

delrin cheap and turns like butter

HDPE.

 

[SF-Guy]

Hello,

Can someone steer me in the direction of obtaining plastic for prototyping in a 4-axis CNC? I am looking for bars that are roughly 36"x6"x3" to run in the mill prior to using aluminum.

Thanks!

I like UHMWPE Ultra-high molecular weight polyethylene i drill it, machine it, thread it. mill it and polish it. I also make some parts of of it. Great stuff.
ebay has aluminum bars and round stock in short pieces also.