Hey G'day folks,

Some advice please..

I have a number of 9/11 mm perspex sheets varying sizes average sizes 12 x 14" thereabouts.

Thought I'd give a go at doing some reverse bas reliefs in the medium. I did this using a tapered ball nose 1mm radius. (I thought I'd try the tapered)

It was my first try conventional offset, started at the middle of the piece and ended up with a nice piece. Its come out good enough for me to use as a mold and try my hand at Cold Casting a couple extra. (something else on my bucket list to have a crack at)

Now I have tried unsuccessfully to do some other work, using single spiral end mill 2mm and 3mm, (cutting some pieces for other small projects that I have) with little to no success!

Spindle speed, 18000 according to doctor google but that didn't do me much good, the bit was not ejecting the shrapnel well enough, particularly doing a profile cut.
Faster spindle feeds, only melted the perspex which then stuck to the bit cooling and making problems. The melted bits got progressive larger and well you can imagine the result.

Tried slower feeds and speeds, ended up snapping a couple of bits.

Using a 6mm endmill produced somewhat better results but its too large for what i need it to do.

Trying to peck some holes for threading the bits tend to melt their way through rather than cut.

If anyone has worked with perspex, a tip on the type of bit to use, speed and feeds would be great.

At the moment it seems more an accident that I got a nice piece rather than by design.

Dr Google isn't helping much.




Cheers,
Steve


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