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Pestmaster
11th Oct 2005, 09:22 PM
What has other members found to be the best way to cut perspex acrylic sheet ?
I have a variable speed jigsaw but do I need a particular blade ? I know I need to use a slow speed.
Can the perspex be scored with a Stanley blade and snapped ?
Thanks for helping...

rick_rine
11th Oct 2005, 09:26 PM
i often cut plastc for the kids , mostly just on the saw table with the blade low , sometimes on the compound mitre saw and sometimes on the bandsaw . no problems . i doubt you could score it and snap it.

as scoot says , leave the paper on as long as possible .

sandman
11th Oct 2005, 09:36 PM
The Bandsaw!
Iv'e recently cut quite a bit of perspex on the bandsaw (not too coarse a blade) with great results. Not a single drama.
Probably wouldn't consider any other method now.
regards Sandman.
:) :) :)

scooter
11th Oct 2005, 09:36 PM
Gday pest, jigsaw with sharp fine blade on slow speed (less melting) as you said will do, as will wot rick sed. If jigsawing, ensure workpiece is held down well so it doesn't snag on blade and chatter (with consequences :( )

Main thing if jigsawing or hand saw is not to rush the cut, or you can get small stress cracks radiating from the cut line.

Leave paper on the plastic as long as possible.


Cheers................Sean

E. maculata
11th Oct 2005, 09:56 PM
as scoot says , leave the paper on as long as possible .



This statement was made 10 minutes before Scooter said it, :eek:

Al, Grunt calling all foilies, quick quick the aliens are here.

rick_rine
11th Oct 2005, 10:02 PM

This statement was made 10 minutes before Scooter said it, :eek:

Al, Grunt calling all foilies, quick quick the aliens are here.

What can I say , I'm a mind reader and lets face it , it doesn't take much to read a mind a small as scoots :)

scooter
11th Oct 2005, 10:19 PM
Never a truer word, etc... :)


Cheers..............Sean, micro mind

Eastie
11th Oct 2005, 10:52 PM
I recently cut some on a scms (wih an 80t blade with monimal rake) as I was too lazy to go out to the shed or cut it by hand. The first two cuts went fine - the third cut shattered the sheet and sent three pieces flying, each about the size of an open palm. One hit the blade guard and fractured it, another hit me on the hand causing an insignificant cut and the other I'm piece I'm yet to find. Not something I'll try again soon.

duckman
12th Oct 2005, 05:34 AM
On the rare occasions I've had to cut perspex, I've used a diamond blade in a 4" angle grinder, the same blade I use for ceramic tiles and all manner of other things and then cleaned up the edge of the perspex with my router. :)

Grunt
12th Oct 2005, 07:11 AM
If you want really smooth edges of your perspex, get one of them butaine blow torches, light her up and run it down the edge.

Pestmaster
12th Oct 2005, 06:29 PM
Well, I don't have a bandsaw, but I do have a triton saw table, but I would of thought the speed would of melted the perspex ??

Looks like the slow jigsaw with a new fine blade will do it. I intend to stick some broad packing tape to the base of the jigsaw so as not to mark the plastic sheet or the perspex.

Thanks to all who replied, this bulletin board has to be the most friendly I have come across in internet land. Cheers

PestMaster

Mulgabill
12th Oct 2005, 07:03 PM
As a part of my work I often have to cut perspex/plexiglas.

For small peices I use the table saw or for larger sheets I use a circular saw on a table.

Melting is minimal and not a real problem and it is easily filed or broken off. Both saws have multi purpose hack-saw blades normally used to cut aluminium.

The trick is to make sure the sheet does not lift which will cause it to shatter and to feed it slowly and steadily.

soundman
13th Oct 2005, 09:51 PM
My choice would be table saw with a fine blade preferably negative rake ( i would mount up an aluminium cutting blade).
Allways with plastic controll of the cut is important, it will bite soon as look at you. Make sure the job is flat on the table the fence is straight with the blade and the sheet runs tight to the fence and the feed is smooth. I would run the blade at full height to minimise the posibility of kick back.
Better still get it cut to size.
Band saw would be my second choice unless the piece was small or curved then it would be #1.
You will have to be real carefull with the jigsaw.
sharp blades always.
Be very carefull with this stuff, if it breaks up & gets thrown around its worse than glass on some ways.
cheers

rick_rine
13th Oct 2005, 09:56 PM
My choice would be table saw with a fine blade preferably negative rake ( i would mount up an aluminium cutting blade).
Allways with plastic controll of the cut is important, it will bite soon as look at you. Make sure the job is flat on the table the fence is straight with the blade and the sheet runs tight to the fence and the feed is smooth. I would run the blade at full height to minimise the posibility of kick back.

cheers

What is negative rake ? Are the teeth facing inwards ? Good point about the saw blade height , I'll take that on , I always did it low but your idea makes more sense and it will also help "pull" the material down onto the bench I assume .
Where are my pancakes ?

normell
14th Oct 2005, 05:55 AM
Another trick is to use a non tiped blade, put in reversed, if you know what I meen

Normell

Pestmaster
15th Oct 2005, 06:13 PM
Well I have successfully cut my acrylic sheet.
I used a new Jigsaw blade Sutton Tools 13TPI 2mm on a fairly slow speed and all went well... :D
I did leave the protective coating on but found that a piece of white paper below allowed me to follow my line more accurately.
Thanks for all the replies

soundman
15th Oct 2005, 07:08 PM
Great to see a sucessfull cut on the job. :D

on rake
The rake of the saw blade is the angle between a line thru the center of the blade and the face of the tooth. A positive rake indicates that the face of teeth are angled forward in relation to the line, a negative rake the teeth are angled back. The positive rake may be as much as 15deg negative rake is usualy only a couple of degrees. The teeth still face the same way.
A negative rake gives more of a scrape cut.

I would strongly recommend against ever putting any blade in a circular saw backwards. I've seen & heard this old chestnut many times before, I have never heard a credible account from someone who has used thus and found sucess.
A mate tried this method for cutting steel sheets ( which is one of the mythical applications) All he managed to do was rip all the teeth off the blade.

I can not see how it could possibly work effectively, it can't possibly cut because the teeth are pointing the wrong way. It may make a very ugggggly hole but it wont "cut". Apart from that the saw will want to kick back out of the cut.

Saw blade backward, not safe not effective, don't do it.

cheers

SAISAY
13th Dec 2007, 02:20 PM
My perspex fabricator friend up in Cairns to me to use high speed saw (for small pieces I use my scroll saw, for larger ones the bandsaw)to minimise melting and reglueing the perspex. If there is no paper on the perspex, use removable spray glue on newspring. It acts as a lubricator and coolant.
Since I did this I have had nice clean edges.
LW

forunna
13th Dec 2007, 11:44 PM
I bought a piece today. watched the guy cut it on a panel saw with a low set blade, didn't get a good look at the blade though.
this was from a specialist acrylic supplier so thats all they do so I would think he knows what he is doing.

Pusser
14th Dec 2007, 07:17 AM
I bought a piece today. watched the guy cut it on a panel saw with a low set blade, didn't get a good look at the blade though.
this was from a specialist acrylic supplier so thats all they do so I would think he knows what he is doing.

Ditto

I bought cut sheets from an acrylic supplier. Aluminium blade (negative rake) low set on a table saw. Bought myself a Bosch aluminium blade and it works fine.

MrFixIt
14th Dec 2007, 10:39 AM
Another trick is to use a non tiped blade, put in reversed, if you know what I meen

Normell

What?:o

MrFixIt
14th Dec 2007, 10:54 AM
Hi

I have cut acrylic sheet / perspex with a table saw, Radial Arm Saw, bandsaw, mitre saw and a jig saw. All of these saws cut the perspex quite easily and do a good job with a "normal" wood cutting blade. The melting that may occur is usually insignificant and is easily cleaned off the cut edge.

IMHO I don't see the need for a negative rake blade, though it would not be a problem using such a blade.

As with all cutting, cut your perspex with care and do it safely. Perspex can shatter (as per another post in this thread) such shattering is more likely to occur with thinner sheets. It is important to ensure that the perspex is supported close to the cut line.

kman-oz
14th Dec 2007, 12:30 PM
I've cut plenty of 19mm perspex panels using the SCMS with an 80T blade. The only time it even cracked was when I got lazy and held the peice down by hand instead of using the work clamp; the peice moved and contacted the blade where it wasn't suppoed to and cracked a bit off. No big deal on this occasion, but it's always wise to use a clamp for this stiff.

I haven't tried the table saw yet, but I'd be just as confident using a sled and work clamp setup.

soundman
14th Dec 2007, 06:55 PM
Aluninium blade....... exactly..... i'm sure i've said that before.

be sure to controll the feed rate and make sure the work is properly restrianed by the fence or a good mitre guide.

Perfect table saw technique is what is required.

you can cut acrilic will all the normal tools....no fancy egative rake blades or drills or whatever...... but your controll and technique must be perfect.

negative rake cutters just makes it a bit easier.....but you still need super care........a tiny bit sloppy and the job will look uggly very quickly.......get too sloppy and it will get dangerous.......a grab or kickback in acrilic can be very violent and fresh cut or broken acrilic is a lot sharper & harder than wood.

By all means get a negative rake right cutter...... but care, care, care.

cheers

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