last little thing?.....Mec-Gar mag bottoms

[G.T.]

It very soon becomes a project in stability..... A mill, or a Lathe, usually have considerable "stiffness & stability" built into the spindle or quill..... so if you can hold the work, you don't have to worry about chatter... if you have a real good drill press, and mount the tool bit as high as you can and move the quill as little as possible, you might have good results IF the work is clamped tight as well.... 5/8" and larger are pretty stout bits, especially if sharp?.... With plastic, you just might get away with it..... turn it slow??? otherwise, you're probably going to have issues... ... best to all, til...lat'r...GT...

[ithacaartist]

Originally Posted by G.T.

It very soon becomes a project in stability..... A mill, or a Lathe, usually have considerable "stiffness & stability" built into the spindle or quill..... so if you can hold the work, you don't have to worry about chatter... if you have a real good drill press, and mount the tool bit as high as you can and move the quill as little as possible, you might have good results IF the work is clamped tight as well.... 5/8" and larger are pretty stout bits, especially if sharp?.... With plastic, you just might get away with it..... turn it slow??? otherwise, you're probably going to have issues... ... best to all, til...lat'r...GT...

I had some experience in the past drilling holes in Lexan and Plexiglass. The secret for success, particularly in hand work, is a material-specific bit that is profiled to cut plastic. The edges are barely relieved, so the cutting edge is very close to 90 degrees, and they more scrape than cut. A regular bit will dig right in and advance without enough material being removed per revolution. This, in turn, causes binding--just like driving in a wedge--and the piece will pop/crack/shatter apart. Using something with a controlled rate of advance, such as the mill, helps a lot. I'm wondering if a pre-heated bit would net better results on the brittle plastic ones.