Cutting tools and speed for acrylics

[Brian Brown]

What tools do you use for cutting acrylics? I have tried several. Scrapers caused them to explode. A bowl gouge works, but has caused some chipping especially in the bottom of coves, and requires very slow, light cuts. Very time consuming. My skew works but is much slower than the bowl gouge, and causes some chatter. I have heard that a negative rake scrapper works, but I don't have one. I would rather not buy new tools if I can use what I already have. What about lathe speed? I will be using pen blank sized blanks. Some acrylics seem more brittle than others. Does anybody have any advice for me to make the turning faster and better. Any advice on techniques? I don't plan on turning a lot of acrylics, but they are nice for razor handles, because they are impervious to water.

Thanks for the help.

[Scott Hackler]

Razor sharp gouges, slow steady motions and fast speed (works for me). Once it's rounded you know you doing it right if you keep having to stop the lathe to remove all the plastic strings!

[Sid Matheny]

+1 for Razor sharp.

[Brian Brown]

I honed my tools just prior to starting, so I feel good about that. The little plastic strings are making me crazy. They pile up on the gouge tip, and get wrapped around the spindle, making it impossible to see what I am doing. I was thinking about setting the hose from my shop vac over the spindle to suck up the strings before they wrap around the spindle. They make quite a mess. How fast is fast speed?

[Len Mullin]

How fast is fast speed?

Brian, for turning acrylics, I usually run my lathe at about 3/4 top end speed. I'm not sure of the exact number of how many RPM's that is, but, it's around 2000.
Len

[Michelle Rich]

spindle gouge, skew, and 2000 and up.

[Thom Sturgill]

Brian, I was looking on-line for some acrylic to turn miniature goblets from. I found that the acrylic comes in two forms - cast and extruded and that the extruded is NOT listed as machinable. Having turned acrylic pen blanks in the past and gotten long streamers of plastic I tried a piece of acrylic that my D-I-L had - a scratched roller for FEMO dough. It was hard and brittle and very poor to turn. I suspect that it was extruded and that the extrusion process 'work hardens' the material much like it does metal.

[Carl Civitella]

Sharp tools and as fast as your lathe will turn. Sand wet with dish soap. Carl

[Bruce Pratt]

In addition to techniques listed above, I have also found that friction heating of a piece also seems to improve cutting. Definitely different grades of plastic affect ability to cut. Truestone comes in 3 densities, the hardest seems only to cut well with carbides. For sanding, I have found dry micromesh to work well