Large Scale Central

Drilling Acrylic

How does one drill a 1 inch hole in 3/16ths acrylic sheet?

I have recently learned several methods of how not to do it

Rick

At work I use a wood bore. Go slow (light pressure) and don’t drill all the way through from one side. Half way or less, flip the sheet over and drill the other side. Keeps it from cracking. I’ve also had good luck with standard bits so long as they are sharp and use light pressure.

Are you sure it is acrylic and not poycarbonate? Poly resists breaking, but when it does it breaks/shatters explosively. I’ve been nearly seriously injured trying to cut 1/8" poly on a panel say. I few inches into the cut it shattered sending shards everywhere. None hit me, but I found one embedded in a cardboard box across the room.

Plexiglass and Lexan are trade names for polycarbonate sheet.

EDIT to add: I’ve never tried a 1" bore; but have good luck with 1/2" and 5/8" bores. By wood bore, I mean the flat bits…

have you tried a good quality hole saw?

Dennis

you can clamp a acrylic sheet between two pieces of wood and use the above type bit to drill through wood with the acrylic sandwiched between the wood

Ricky,

I second Dennis’s suggestion of a hole saw. Again, as Jon stated, go slow, remove chips from the saw often and go from both sides.

An alternate, search the internet for ‘drilling acrylic’ or ‘how to sharpen a drill bit for acrylic’ or variations on those themes. I found several articles that might fill the bill. You can also purchase commercially manufactured bits for acrylic.

In case you forgot, you really don’t cut acrylic, you scratch a break line. The problem with standard drill bits is the way the drill is ground for metal allows the bit to cut too deeply too fast creating very high stresses that shatter the plastic. I have had success taking a standard drill bit and grinding a much flatter cutting face on the flute of the bit, making it more like the cutting face of your sheet cutting tool. That said, I have never cut anything as large as a 1" hole.

Good luck.

Bob C.

Tape the drill spot !!!

I use forschmer bits with great success. The key is to go slow. Advance and lift letting the chips clear. Otherwise they melt in the hole fuse everything together.

Rick - if you have access to a laser cutter they really do a superb job on acrylic, Plexiglas, etc

dave

If I need a hole in acrylic, I’ll start it with the laser and can then easily enlarge it with a drill.

But I think that you could also “friction” though it using a grinder bit.

I’ve been working for TAP Plastics since 1980 and I’ve cut,drilled and machined so much Acrylic, Polycarbonate, ABS and Styrene over the last 37 years that I think I can be considered an expert.(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-smile.gif)

First… Acrylic or officially Methyl Methacrylate (MMA) goes by many names… Plexiglas, Lucite, Acrylite, Perspex, Polycast, Chemcast to name just a few. It takes special tools to work with acrylic so you do not break or stress the material during machining. We really like to do any holes larger than 1/2" using a router and carbide flush trim bit and a pattern. This induces the least amount of heat into he plastic and reduces cracking. If we are going to drill the large hole we use a step drill like an Irwin UniBit. These have to be used carefully but they give a really nice clean hole. We do not use any of the “Spade” or “Paddle” type bits as they can easily crack the material. We do not use Hole Saws either for the same reason…A Forstners Bit will work but they do tend to overheat the acrylic and tend to crack the acrylic on exit if not supported. Overheating causes stress in the acrylic which makes the area more susceptible to stress fracturing when the area comes in contact with certain chemicals, including alcohol. This is a big problem with LASER cutting acrylic also.

I’ll be doing a plastics talk at my Store in San Leandro during the BAGRS Swap Meet on April 22nd. Everyone is invited!

Russ Miller

TAP Plastics Manager, San Leandro

NGRC 2016 Chairman

Thanks for all the tips Guys

As I said at the start I had tried several methods with varying success.

The best I found,(no access to a laser cutter) was actually the hole saw and the step bit that Russ mentioned, ran very slow. They both gave me a clean hole on a flat supported surface in the drill press.

But

The part I forgot to mention was that I didn’t think about the holes until the sheets were all glued into the shape of a building and no way to support the material from the back side while drilling/cutting/etc. (http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-embarassed.gif)(http://www.largescalecentral.com/externals/tinymce/plugins/emoticons/img/smiley-foot-in-mouth.gif)

So I did it the old fashioned way; drilled a series of small holes around the circumference then broke it out and cleaned it up with a rasp. Worked great the louvers snapped in perfectly.

Thanks again

Rick

how would this work… can you spray with water to help cool it?

Sean McGillicuddy said:

how would this work… can you spray with water to help cool it?

These can overheat and melt the acrylic. Another big problem I have with hole saws is removing the plug out of the hole saw as they end to bond themselves into the bit. They are really not the best option so we avoid them.

Russ

Hey Russ,

Its nice t have an expert on the issue and I think you more than qualify. I have played with a fair amount of acrylic an appreciate your advice.