Machining acrylic

Hi everyone, I've just bought some 10mm round acrylic rod to make lenses for two 16mm scale buffer stop lamps. If I was turning them in brass I wouldn't be troubling anyone, as I can happily create the shape I need. My concern is turning acrylic, as I've never worked with it before.

So my questions are: Do I need lubricant? Will sharp HSS tools do it? What speed do I run the lathe at? How do I get a nice finish?

I would be very grateful for your thoughts, please.

Regards,

John.

I,v been doing a bit of work on Nylon over the last few days, and trying a newly made carbide tool, but I think the HSS may be better.

Ian S C

Sharp hss is fine - I use a high speed and a light cut with a fine feed rate. Polish with fine grades of wet and dry, say 220, 400 and 1000 grit. Finish with a spot of Brasso on a soft cloth.

Just been making some washers from , I think ,acrylic. Just used same HSS tool as aluminium, no lubricant.

Polish with finest grade wet & dry or sponge block, then polish with autosol on a thick tissue.

Neil

Why not go and get some 10mm LED's from somewhere like Maplin ?
They come pre shaped and polished and the light will auto work..... ​

http://www.maplin.co.uk/p/10mm-white-led-n83kg

Edited By Alex Collins on 17/10/2015 11:30:00

Edited By Frances IoM on 17/10/2015 11:56:30

I've turned acrylic using an hss toolbit in my spherical turning attachment to make a lens for an optical centre finder. Found that material tended to 'pick-up' badly if it gets too hot, After some failures (experimentation?) I found that a fine feed, fairly low rpm and coolant gave a clean cut. I used WD40 as the coolant, and it seemed to work ok, with a much better finish than when machined dry - and no 'picking-up'.

This was followed by polishing with wet and dry of around 800 grit and then Solvol Autochrome metal polish. The metal polish transforms the finish and visibility through the lens.

I used to mill acrylic rod dry with a very sharp cutter no problems. Polished ends with fine wet and dry used wet followed by brasso. They were optical components so had to have a polished finish.i

It's Mark Noel. Wait 'til his 'multigrinder' appears in MEW

Neil

**LINK**

[presumably] not to be confused with the Tattoo Artist.

MichaelG.

Red Leicester sounds good Grommet!! Lets get some in, shall we?

A dip in pure Acetone will give the final polish to acrylic. Just in and out then let it dry naturally.

Thank you all for that- I'll get stuck in tomorrow and see how I get on. I can't bring myself to waste *CHEESE* in the lathe, so it'll have to be WD40 or Lipsyl!

I would normally use LED's, but I'm using up my old stock of miniature bulbs as I can't bear to waste anything!

Thanks again all.

John.

Edited By Frances IoM on 17/10/2015 19:20:22

Hello again everybody...well, I couldn't wait until tomorrow, so I got stuck in and made the two red lenses out of the red acrylic rod. Sorry it's not a great photo, I only had my phone to hand.

The acrylic machined beautifully, no noise, just pink ribbons of 'swarf' peeling off (that reminded me strangely of a favourite childhood confection), tending to hang about due, I imagine, to static electricity. I used no lubricant, sharp HSS and steady turning speeds and was delighted by the results.

Another string to my bow, and thanks again for all the great advice freely shared!

Here are the unfinished buffer stops with the buffer stop lamp illuminated. I just need to get on with the weathering and distressing now.

Regards,

John.

Polish with flame from torchlamp. **LINK**