I need to cut some acrylic sheet into an accurate shape. What's the best way of doing this accurately to a professional finish? If I do it by hand it's bound to look DIY, so I'm guessing it's best to draw it in CAD and get it cut on a CNC machine of some kind. Will a laser cut it? Or water jet maybe?

Also note that the middle layer needs to be ~8-10mm thick. Not sure if this affects the answer or not!

Thanks, Chris

Funny enough I am looking into a similar task and water cutting seems to be the best option, giving a nice satin edge and ok with very thick materials (3" or so)

Waterjetting would be ideal.

However, depending on the shape, you can achieve a pretty good result with a jig-saw. That thickness is probably just about perfect as well.

What are you making, if you don't mind me asking??

I want to make some custom guages. Plan is to cut the top layer out of thin black to make up the circles for speedo and rev counter, then a thicker layer out of frosted behind that. I'll cut the guage designs out of vinyl and sandwich in the middle, then light it all with LEDs. Not sure if it's best to put them behind the frosted stuff or drill 'horizontally' into that layer and glue them in. Have to experiment.

Thing is that they will be in direct line of sight the whole time, so they need to be cut accurately if they're not to look amateur.

Chris

In my case I am making a kind of frame for an air filter. It is a pretty unusual shape and needs to have the same contour as the alloy backplate. Acrylic seems to be the way Ramair and Pipercross do it, using it to support a mesh frame which then has foam bonded to the outside. Alloy would be even nicer but it needs to be 15mm thick so a huge billet would be needed and cost would be too nasty.

Sandwiching vinyl between two layers of acrylic sounds tricky as you will end up with air pockets - how about printing them on acetate sheet and then sandwiching that?

i tried cutting 12mm perspex with a jigsaw, the blade just clogs up as the plastic melts, then solidifies in the cut. waterjet is the way forward i think. i asked andyw7de about milling perspex before to light the edges and have a work in the middle like up, but not cut all the way through. he couldn't do that, but sugested cutting the words on the water jet, then sandwiching that with another sheet of perspex

I made the windscreen and side windows of my Lotus Eleven rep with a router. I had to first make a wood guide and fasten it to the perspex, but it cuts very easily with a router using a shaping bit. Its messy and noisey, but if you have a router table its do-able at home.

I cut my DIY Aeroscreen on a table saw (rip saw) just fine. Finished the round edges off with a Jigsaw with a Hacksaw blade in it. Doesn't clog up and gives an acceptable edge. Some wet and dry to finish

Router is a good call also

Dan

[Edited on 13/1/11 by dan8400]

certainly doesnt clog up and melt etc. if you use the right blade and speed. The only thing you might get with a saw (any type) is that you might get slight vertical streaks along the matte edge, but that can be taken off with wet and dry in a couple of minutes.

If it's a small radius cut though, you may struggle to do it with a saw whilst keeping it perfectly round. you'll need some sort of guide for your saw or jig saw.

quote:

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Originally posted by dan8400
I cut my DIY Aeroscreen on a table saw (rip saw) just fine. Finished the round edges off with a Jigsaw with a Hacksaw blade in it. Doesn't clog up and gives an acceptable edge. Some wet and dry to finish

Router is a good call also

Dan

[Edited on 13/1/11 by dan8400]

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cnc mill is how I get all the fancy acrylic work done, but just cutting to shape and cleaning up the edge will leave a perfectly acceptable finish, all depends on the accuracy you need, if its square then a flat bed saw with a TCT saw blade is about as good as your going to get with simple tools

one way to get rid of any saw marks along the edge if its to be exposed or polished for illumination purposes, is to take a stanley blade, and drag it along the edge, with the cutting edge trailing, this has great effect, removes minimal material and leaves a smooth surface

can easily be polished with a wheel and maybe vonax polish? or something similar, otherwise wet and dry also works.

if you have text or image etc milled into the surface and then edge light the panel, you will get good looking display

[Edited on 13/1/11 by tony-devon]

quote:

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Originally posted by blakep82
i tried cutting 12mm perspex with a jigsaw, the blade just clogs up as the plastic melts, then solidifies in the cut. waterjet is the way forward i think. i asked andyw7de about milling perspex before to light the edges and have a work in the middle like up, but not cut all the way through. he couldn't do that, but sugested cutting the words on the water jet, then sandwiching that with another sheet of perspex

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Another option would be CNC Router.
Jonathan Rarity (well known hillclimber) runs a CNC routing outfit
Artistic Engineering

He has made a few parts for me in the past.