Machining Perspex

[Soapyjoe]

Hi Everybody,
I wish to make a set of components from 10 mm clear Perspex.
The finished component must be as near as possible glass clear.
I am interested to know what is the best combination of machining setting for this type of material.
I contemplate having to spend quite a bit of time finally buffing the components.... here again your recommendations as to compound would be appreciated.

Thanks in anticipation

Soapy

[IslaWW]

What type of machining do you need to perform? If simple profiles, laser cutting will yield flame polished edges

[Soapyjoe]

Hi,
I am machining a set of components to convert a Dodecahedron into a sphere.... each of the 12 additional faces will resemble a type of lens.

[Soapyjoe]

Similar to above

[Samson]

I can say from a polishing point of view, there is going to be a lot of work involved to get it back to optically clear and smooth.
The faces will have a lot of mill marks to remove before even starting the buffing process. With contours on the surface, it's going to take time to remove the mill marks and retain the shapes without dips and ridges. Any imperfections will show when polished.

[Savannahdan]

Perspex has a nice pdf file on their website regarding milling, cutting, sanding, etc. their product. Very informative including the need for annealing. Have fun.

[Soapyjoe]

Thanks everybody,

Reading comments I will definitely need to make some small trials before I venture into the whole project.... The removal of the tool marks that will be the major problem.... I will read the Perspex recommendations.

Soapy

[TReischl]

"flame polished" is an interesting term, especially in the laser world. Yup, the edges will be clear, right along with striations. We spent a ton of time trying to eliminate them, we were never totally successful, at least not as far as a potential customer was concerned.

[TSM2018]

https://howtolaser.com/blog/how-to-laser-cut-acrylic/

This was posted to my q&A about the Design & Make DIY CNC with dremel. I do find this resource helpful. I think I should use my router with multiple brands of acrylic from retail and private suppliers, and complete my own tests. Just a small carve and see what happens.

I find the green edge acrylic to be an interesting option, too; I haven't purchased, but I am interested in how it machines.

I have only polished over gas flame on my kitchen stove (at my own risk...) It was a really small piece. Do you need a fire extinguisher on hand? I probably had mine out and next to me. Guess I should look that up before I experiment again.

Importing Perspex in the US from the UK, seems a little expensive for me, so I will try common options here in the USA.

[fixtureman]

A 75-012 Onsrud mono-crystalline diamond polisher would do it. check out the 7:43 mark on this video. There is a lot of good advice on cutters here

[highpockets]

How about creating a mold to cast the pieces?