How to cut acrylic circles?

[Whiskeymike]

What options are there for cutting 14-18" circles in acrylic sheets that are 1/8-3/16th? I need a bunch of them and looking for a fairly quick reliable way to cut them. I have access to most shop tools like drill press, band saw, etc..

I'd prefer to do it without a hole in the center.

 

[ilovevocs]

Laser Cutter, router and trammel, router and template.

 

[Whiskeymike]

I have access to a laser cutter at techshop. Maybe that's the fastest/repeatable way. I was thinking that it would be rather slow.

I found some circle cutters with blades at the end, but they seem to tap out at 8" in diameter.

 

[ilovevocs]

We had a huge laser at my grad school. Cut tons of acrylic on it. Makes for a very nice finished product. It may take time but its not like its hard work, you just sit back and read garage journal while it runs.

 

[Gerald O]

Laser might leave burned or melted edges. CNC router is an alternative.

 

[ilovevocs]

^ Not the slightest bit based on my experience. The laser is a single process for making these parts. With the right setting the edge should be as close to perfect as your going to get.

CNC router would work too if you have a vacuum table to hold the material. If not you have to tab all the circles so they do not detach during the machining process, cut them with a bandsaw, and then do some surface finishing. Double sided tape is always an option for securing flat stock like this but the clean up and its subsequent impact on the surface finish quality would be my primary deterrent.

 

[A_Pmech]

Laser is by far the best option for acrylic. The edge will be heat polished and almost transparent.

 

[EdT]

Since you are doing a lot of them, you will be buying a lot of acrylic to cut them from. It couldn't hurt to ask the plastic supplier what they would charge you to cut the circles. By the time you get the stuff to do it and figure it out, it might be a bargain to have someplace that cuts plastic all day do it for you. OTOH, it could be stupid expensive, but asking is free.

 

[EdT]

I checked online and the first place I looked, Delvies Plastic, sells a 12" x 1/8 disc for $8.10 which seems like a deal to me.

 

[Gerald O]

^ Not the slightest bit based on my experience. The laser is a single process for making these parts. With the right setting the edge should be as close to perfect as your going to get.

CNC router would work too if you have a vacuum table to hold the material. If not you have to tab all the circles so they do not detach during the machining process, cut them with a bandsaw, and then do some surface finishing. Double sided tape is always an option for securing flat stock like this but the clean up and its subsequent impact on the surface finish quality would be my primary deterrent.

Laser is by far the best option for acrylic. The edge will be heat polished and almost transparent.

I agree that laser can do the best job; the question is can the OP do the best job with the laser he has access to. There's likely to be a learning curve and a lot of test cuts to get the settings right -- assuming the equipment is up to the job.

 

[zhaddock]

Laser might leave burned or melted edges. CNC router is an alternative.

If the laser is set up correctly it will leave a nice almost polished edge.

 

[tarbellb]

Yup, as others stated.

LASER is super fast, accurate, and clean edges.


Lots of information out there on what settings need to be used.

 

[bullnerd]

What's a bunch? 20? 500?

 

[kazlx]

Like already stated. The laser is the best bet. It's relatively quick, and most of all, ready to go right out of the cutter. But I would also just contact the supplier. For something that basic, it's probably going to be cheaper/easier/faster to buy them already cut.

 

[Whiskeymike]

What's a bunch? 20? 500?

Probably 200. I"ll get some stock and try the laser. It's a Trotec and definitely capable. It probably won't be bad if I setup a jig.

 

[Robert Haas]

I am a glass shop owner and we sell and fabricate Plexiglas which is a trade name for transparent acrylic sheet.

The low tech way to do it is with a jig saw mounted to a straight edge/arm that is screwed to a sacrificial sheet of material. we stack up multiple sheets of acrylic and clamp the outside corners together, then lay our saw/base ina location that allows us to begin cutting.


We have been able to do this in a production manner and produced several hundred diam.s in a few hours.

 

[APEowner]

I've used a trepanning tool to cut large circles in acrylic. You'll want a milling machine or a drill press with a ridged setup and a slow spindle speed as cutter speeds can get quite high quickly when you're swinging a six or seven inch arm.

 

[Ole Slewfoot]

Small laser made me this one in 0:01:25

 

[foghorn1966]

200 is a lot. Hass's method is similar to how I'd do it, plywood or MDF jig, made using a center pin & router to make perfectly round. Then two side tape the lexan / plexi to the jig & router them out.