ChrisW
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| posted on 12/1/11 at 11:22 PM |
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Accurate cutting of acrylic sheet (perspex)
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
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RazMan
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| posted on 12/1/11 at 11:30 PM |
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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)
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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PSpirine
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| posted on 12/1/11 at 11:35 PM |
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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.
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ChrisW
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| posted on 12/1/11 at 11:36 PM |
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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
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RazMan
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| posted on 12/1/11 at 11:45 PM |
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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?
Cheers,
Raz
When thinking outside the box doesn't work any more, it's time to build a new box
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blakep82
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| posted on 13/1/11 at 12:56 AM |
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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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don't write OT on a new thread title, you're creating the topic, everything you write is very much ON topic!
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cs3tcr
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| posted on 13/1/11 at 02:37 AM |
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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.
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dan8400
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| posted on 13/1/11 at 06:36 AM |
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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]
Hey - That's Journey!!!
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PSpirine
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| posted on 13/1/11 at 07:19 AM |
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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.
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MakeEverything
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| posted on 13/1/11 at 08:40 AM |
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quote:
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]
Ditto. This is what i would do.
Kindest Regards,
Richard.
...You can make it foolProof, but youll never make it Idiot Proof!...
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tony-devon
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| posted on 13/1/11 at 08:45 AM |
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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]
heavy is good, heavy is reliable, and if it breaks, hit them with it
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bitsilly
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| posted on 13/1/11 at 09:44 AM |
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quote:
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
I used to teach making stuff with Perspex. The above can be avoided by putting sellotape above and ideally below the line you want to cut.
Sounds unlikely I know but really works.
We would scrape the edges with edge of a ruler to get flat, then fine wet and dry, then polish it with metal polish if you want a shiney edge.
Most schools now have laser cutters, have a word with the schools technician and offer to contribute some materials or something and it should get
done.
It is a doddle to add text etc too.
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minitici
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| posted on 13/1/11 at 10:08 AM |
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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.
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