Clear Acrylic Help Please.

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Marsh

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Hi All, I am making a display case and need some clear acrylic sheet 4 to 5mm. Who is the best to supply me with this (I live in the UK)?
What is the best tool to cut it with? I have looked in B & Q but it is poor quality.
Thanks in advance Marsh.
 
Marsh: First of all keep in mind there are two kinds of clear synthetic material made into sheets. when you say acylic I think Methleacrylate aka lucite. plexiglass and perplex. the later development is polycarbonate plastics.

there are two methods of cutting you can saw it like wood or metal or you can score and break like glass.
I have a friend that has made many case for his models and he uses a trim bit in his router to trim to size and get a clean edge.
You need a smooth edge to effectively fabricate it exposed edges need to be polished . i use 320,400, 600 grit silicon carbide paper then auto finishing compound and plastic polish. edges to be welded just need to be smooth and straight. they can look a bit frosty .

the best way to attach it to itself is with a chemical weld set the pieces in place and use a n applicator similar to a syringe needle and the capillarity action draws in the fluid and welds it in place. use caution , gloves and ventilation (outdoors as the solvent is nasty) a place I work bottles it they use positive pressure environmental suites in a negative pressure isolation room. Dichloromethane (methylene chloride), which is obtainable in paint stripper, can solvent weld polycarbonate and polymethylmethacrylate.

Take care with the solvent if it drips and runs it will leave tracks that are hard to get rid of.
this is the stuff we used at the model shop I worked in :
ips_10799.jpg


Here in the US any good hardware store or home center caries plastic sheet stock. and yes I see yo are in the UK .
Tin
 
You could try a sign maker, they use a lot of perspex (acrylic sheet), including clear and the better ones can laser cut it for you to whatever size you want. Laser cutting leaves a very clean edge.....
 
McMaster sells drillbits to cut holes in acrylic. It tends to crack and shatter if you use a regular drill.
 
Hi All, I am making a display case and need some clear acrylic sheet 4 to 5mm. Who is the best to supply me with this (I live in the UK)?
What is the best tool to cut it with? I have looked in B & Q but it is poor quality.
Thanks in advance Marsh.

Get mine from here:

http://www.directplastics.co.uk/acrylic-sheet/

Not sure, but I think they will cut to size.

Dave
 
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You can always buy special drill bits for drilling plastic (probably the best choice if you do this a lot), but I have had some success with the following:

- use a standard drill bit at slowest possible speed
- use a spade bit (drill a pilot hole first with a standard bit to prevent the point on the spade bit from cracking the plastic
- use a Forstner bit
- run the drill bit in reverse

If I want the cleanest possible hole, I always do the following:

- drill a smaller diameter pilot hole first
- use a "backer" of scrap wood to prevent break out and chipping when the drill penetrates

Here are some good links on working with plastic (scroll down to "Plastics"):

https://sites.google.com/site/lagadoacademy/useful-links#info-other
 
Step drills also work great. The key is the rake angle. You can mod a twist drill by reducing rake to 90 °.
 
A sharp trist drill will grab and often break the plexiglas. I learned that when drilling holes in a $1300 aircraft part once. It was not a good day! The method I have used since then is to grind the point angle to nearly 180 degrees from the normal 118 degrees. The other trick which I have no experience with is to run the bit into a concrete floor to dull it. I'm told that will work but have never tried it. The books say use a zero rake angle on the bit. The whole idea is to let the bit exit the far side without grabbing and causing a crack.
 
I've been a model maker for over 36 years and have lots of experience drilling and milling acrylic. The dull drill bit crap is just that. Use a sharp drill or else your just melting a hole into the acrylic. When drilling acrylic you never want the bit to get hot, thats why I recommend using soapy water as a coolant and lubricant. As far as the drill grabbing the acrylic,well thats why you should always clamp the part down.
 

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