Cutting Perspex?

Roach1948

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www.dallimoredesigns.nl
I want to make a little box around the engine control panel with a perspex sliding panel - I have ordered the perspex, but was wondering whether I could cut it to shape safely on the bench saw?
 
Too fast & too much heat, will brobably clog and possibly shatter, it cuts nicely with a jigsaw at low speed or if not too thick then score with a stanley and break, clean up the edges with a rough file or ose a stanley like a wood scraper.
 
I found a jogsaw works well, but heat build up is a problem as it goes all gooey and then wont cut, I got into the practice of cut 1/4 inch, back off 1/4, cut 1/4 and so on, slow progress but a clean cut.

Try to avoid the blade getting stuck, if the jigsaw hammers up and down you might crack the perspex.

HTH
 
I heard a few years back that dribbling a line of cooking oil along the cut line before you cut takes the heat away and prevents gooey meltage - but I haven't tried it...
 
It will cut on a "slow" band saw with a good sharp blade 12/14 tpi. If you have one. Place, tape or clamp on another peace of thin ply under the work piece to be cut and it will save the base plate from making any marks on your job.
My Little Clark metal worker cheep as chips at £120 and now 12 years old, with all the bearing and clamp bolts changed to high tensile works a treat swap the pulleys over to get a faster cut for wood.
 
Jigsaw with a sharp medium wood blade. Cool with a squeezy bottle of water and a bit of washing up liquid. This avoids the build up of hot ´n sticky swarf in the groove.
Be careful of a hand saw, very easy to catch and twist=break the panel. (Did that on an A/C windshield!!)
A job that envolved cutting 30 bits of 10mm for a staircase I cut oversize and trimmed back with a router. Polished up the edges with wet and dry paper and water, three grades.
Shaping corners can be done with an angle grinder and sanding disc.
Re. bench saws. I once cut about 120 4mm strips. No prob with heat or swarf. Fine until the last one, which caught and shot back, taking the skin off the side of my thumb back to the knuckle.
Heat, in general,as with the router, can be good as it tends to seal the edge and de-stress it- less likely to crack. Hope this helps,
Andrew
 
You can use a bench saw provided that you've a TCT blade with plenty of teeth (the more the better) which are sharp, with a slow feed and with plenty of downwards pressure to stop the sheet from bouncing. To stop breaking out too much on the underside you can pre-cut a piece of ply or similar to make a dummy table which you tape onto the normal table reducing the gap around the blade to the kerf width so that the acrylic is well supported as it is cut. The acrylic also needs to be held down at the back of the blade where the teeth are rising. Adding masking tape on top of the normal protective plastic film will help stop the waste from overheating and sticking. But the main thing is sharp teeth and slow feed.
 
Using a laser is the neatest way to do it. Draw it on screen to the size/shape you want then send to the laser. Bonus being that the edges are smooth allmost polished. I have laser here if you want to use it. Cast Acrylic is better than extruded.
 
I agree with Les-W and Transcur's comments. Unfortunately not many of us can afford the laser cutter, but a tct blade on a decent bench saw is ok. The only thing I'd add is that you don't want to set the blade to high - set it so it's just appearing through the top of the acrylic, which gives a longer cut and means it's less likely to break out underneath. Whatever tool you use, the general rule is HIGH tool speed and LOW feed rate - and that applies to drills, bandsaws, bench saws, lathes and milling machines.
As Transcur says, avoid the extruded stuff and go for the cast acrylic - less likely to show stress cracks after cutting and far less likely to melt during cutting.
Personally I always use a bandsaw for cutting sheet. Long straight edges can be cleaned up with a finely set smoothing plane, followed by wet and dry up to 600g, followed by Brasso. Curves can be filed. Drilled holes can be polished with a piece of dowel dipped in Brasso and used in a drill.
 
I've got a variable speed electric jig saw and a blade designed for cutting formica/plastic coated work tops - ie no burr on the formica side. If this is of any use let me know and I'll bring it up to the yard for you.
 
Thanks a lot everybody for the informed response. It could have saved me from a nasty injury! As it is only a really small bit of perspex I reck I will give it a go with a variable speed Jigsaw (I have one). Sorry in the delay in replying but YBW.COM crashed my machine!
 
As many others have suggested a jigsaw works well for everyday projects. Overheating of the blade must be avoided, and one neat trick is to stick parcel tape ( the brown stuff) along the cut lines on both sides pf the sheet. The polypropylene tape melts at a lower temp than the acrylic, and is carried into the cut on the blade where it acts a lubricant and prevents the acrylic from melting back onto the blade. Sounds a bit unlikely, but it really works. Also stops the sole of the jigsaw scatching the surface.
Excellent edge finish can be had by cutting oversize and trimming with a t/c cutter running at slowest speed in a router. Ideally cut a full size template for the piece in mdf, and attach to the acrylic sheet with double-sided tape before trimming with a bearing-guided router bit. That way you can make any sizing errors on the template, not the acrylic. If you don't have the routing kit then it's filing / sanding / scraper etc. as others have suggested.
 
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