4mm perspex - how to get straight cuts?

MikeHunt79

MikeHunt79

MikeHunt79

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I guess some people here may have cut 4mm perspex in the past, be it for car windows or PC case windows.

Does anyone know how I can get straight cuts? I've already tried using a jigsaw, and this is almost impossible to get straight cuts with. Would a circular saw work or would the perspex melt?

Another option I have is 100W soldering iron with hot knife attachment, I was thinking i could use a metal ruler as a guide and melt thru the perspex?

Which would be the best way? I'm down to my last sheet of perspex so I can't really afford to use much more up with any non-straight cuts...
 
Find a local laser cutter circa 80w

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I get these cut on a laser, can't beat them for accuracy!
 
We used to use a bandsaw in tech, so a circular saw could possibly work? Maybe on a lower speed, and possibly with a different blade. Possibly ask a local school's tech dept? I know mine had bandsaws, lasers etc.
 
Don't know if you'll be able to get a good cut with handsaws..... I take it your circular saws handheld? not a benchsaw?

I would either

experiment with mounting your circular saw under a table (i.e piece of mdf with a slot cut in it. screw the saw underneath and rest the tabletop on trestles) I havent cut plastic using a circular saw before though, you'll prob need a special cutter. You can then make a fence using a bit of wood and a couple of clamps.

use the circular saw normally, will prob need a new cutter, i would imagine a wood one will shatter it to pieces. Might not get a straight cut, and could be difficult to support plastic. Risk of scratching it too.

Find someone with access to a workshop (uni?) and do it properly:). I've done it on bandsaws before.


edit: or as above... lasers are frikkin awesome! pew pew! We have one at uni and it shreds through anything.
 
Depending on the size of cut needed, stanley knife and steel rule, then simply snap it.
Just remember to wear gloves and cut away from you!!
 
4mm will be tricky to snap.

Your best DIY bet is to use masking tape and a very very fine jigsaw blade. The masking will hopefully prevent any chipping. Plastic will melt and re-fuse on very high speeds, so go slow.

Any bodges can be filed down. Perspex files easily.

I have had some amazing cuts using a scroll saw then filling.
 
Its the way we do it at work, however it may well be smaller than 4mm (never actually measured the thickness). Was just a thought :).
 
If you use a circular saw put masking tape on both sides along the line your going to cut, it will stop it from chipping away, then it should do a very good cut.
 
Is it cast acrylic or extruded? Cast is pretty stiff at 4mm, would feel much more brittle. Extruded is quite soft, probably be able to mar the surface with your fingernail.

If it's extruded and you cut it with a saw the edge will burr and melt. It will chip off after.

If it's a cast sheet then just hit it with the circular saw and mask the entire sheet (if there's no plastic protection film)
 
You can buy wide jiggly saw blades that have fine teeth. These would be perfect for the task. Then use a blow torch on the edge to make it smooth.

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Trick is to get the saw going full speed with no orbital and move the saw slowly, let it do the cutting. And as said above, use some masking tape on both sides to limit any chipping that might occur.
 
cut perspex lots of times at work on the panel saw no problem there. if you have access to one that is :P
 
Circular saw will work.

You should be able to use a jigsaw though. Clamp a long straight piece of wood (cheap bit of pine, floor board etc) against it and use it as a guide. Just make sure the jigsaw is hard up against the wood all the time and you'll get as good a cut as with a circular saw.

You might struggle with a fine tooth blade because it tends to melt the acrylic rather than cut it. If it does this then spray it with plenty of water to keep the blade cool. As long as the acrylic is clamped tight and can't chatter then you should get a decent cut and no splits or cracks :)
 
I've cut fairly thick perspex using a tenon saw successfully, once the main width of the saw is in the perspex it's very hard NOT to cut a straight line.
 
You're wasting your time with a jigsaw, almost impossible to keep the blade true as it's too flexible /small, even with a straight edge to guide you.

Use a fine toothed wood saw and keep the handle low (not cutting down through it at 90 degrees)
Piece of ****. As godinman says, almost impossible NOT to cut straight doing it with shallow cuts and a wide blade

Have a link on the house :D

http://www.kentsdirect.com/selfbuild_trade_diy/tools/350-fine-tooth-saw.html
 
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Scubascorpion said:
You're wasting your time with a jigsaw, almost impossible to keep the blade true as it's too flexible /small, even with a straight edge to guide you.
Click to expand...

With a bit of practise you can cut perfectly straight with a jigsaw. Its vital to have a sharp, good quality blade and to turn orbital action off for fine work.

With the blade i posted above it would be even easier and would get an almost perfect edge, due to the fact the blades have very little (if any) tooth setting.
 
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