Manipulating plexiglas


#1

Alright, so my next project is to build a stick entirely out of plexiglas. I’m going to be using the 1/4’ thick variety for most of it and I need some tips on working with the stuff, as I’ve heard it isn’t the friendliest material. I’ve got clear-drying plexiglas glue, some polish for any scratches I might incur, and a template all picked out.

The things I need tips on specifically are:

  1. Cutting plexiglas (both straight lines and holes for buttons)
  2. Mounting the PCB
  3. Making a hinged door on the underside

These are things that wouldn’t be a problem normally if I was working with wood, but I’m sure the plexiglas will change that. When I need to use screws (like for the hinge and for mounting the PCB) the best way I’ve thought of is piloting a hole, filling it with the glue and then screwing the screw in. If anyone has some ideas or suggestions before I start ruining materials, please let me know.


#2

Ive seen people using just a dremel
they were working on plexiglas computer cases


#3

a fine tooth table saw cuts it the best out of the stuff ive tried. they usually say they are for veneer cutting. they are pretty cheap too if you don’t have one. for drilling i would say hole saw for drilling or a Forster bit if you take it slow.

hole saw is a pain cuz you have to pop out the plexi after each drill, forster bit gets too hot and will melt the edges a bit. if you take it slow it wont be big enough to be visible with the buttons.

ive only worked with like 1/8 material i doubt it would be much different with 1/4 but who knows.

probably get a project box and put the pcb in that and attach it.

can’t help you with the last one


#4

Well, you mention you have a template; the easiest method I know for cutting acrylic is with a templated edge, a little double-sided tape, and a flush-trim/pattern bit in a router. It’s like cutting butter when you use this on a router table. Using the same full template on each piece will be critical in making them the exact same dimensions.

For drilling, always drill very slowly … drill very slowly. You may want to make a template for drilling too if you are drilling each piece one at a time so they line up. For large holes, hole bits with spurred areas tend to work better I think. Hopefully you have a drill press.

Mounting a PCB will probably work by making a compartment for it; off the top of my head you would need to drill a large hole to start, then work with a templating router.

For hinges, you will need to route grooves for them. I can’t say I know how well screws work in mounting things in acrylic; seems like screws work off of oversizing friction which does not agree with acrylic. You might need just to find something to glue them. A lot of this is just off the top of my head.


#5

Oh and no matter what anyone says, it will scratch, it wont stay nice and glass-like for long, so either make it and don’t use it, or make it and stick it somewhere nice for all to see.

Unless you specifically want the pcb showing Id recommend using a chrome/polished aluminium box for it. Id also say keeping the wires all one colour would look best too (a little confusing when wiring up)

The main bit advice, which has already been said: Take your time, especially when using a dremel. On plexi glass or anything similar it’ll cut through it like butter, and if you slip or make a small mistake its not like you can filler it and paint over.

ps: good luck, it wont be easy


#6

Get ahold of somone local that does custom aquariums. They know how to make strong custom pelxi/acrylic, and might be able to help form what you need. Formed acrylic would look tons better than your normal rectangular pieces glued together.


#7

Most sheets of plexiglass or acrylic are covered on both sides with either plastic or paper sheet so that you don’t scratch it up when you are cutting or drilling, you just peel it off afterwards. There are certain blades for saws that are designed for just cutting plexiglass or acrylic, there’s even drill bits. You don’t want to use a saw blade designed for cutting wood because it can seriously crack your sheet of acrylic. Same thing goes with drilling holes for your screws, you can crack if you’re not to careful. If you got a template of the design you want, you can ask your supplier to even laser cut it for you so your holes will have a nice clean cut but that’s going to cost you a grip depending what your supplier charges. I know some has suggested using a dremel tool but just keep in mind when it cuts, it also melts the excess plexiglass/acrylic material. If you like the idea of making your stick out of just one piece of plexiglass/acrylic, you can use a heating strip or heating gun to bend the edges that you want to fold over. But keep in mind that you might have sand down the edge where the bend is because when you heat the plexiglass and bend it, a little of the plexiglass sticks out. (Just find a piece of plexiglass sign holder or picture frame and you’ll see what I mean about the edges) If you are worry about scratching it, just can always sand it and polish it out. Use like 1000 grit sand paper and slowly work your way up to at least 2000 and polish it out with any of those car polish, I use some the Meguiar’s stuff. I also like to wet sand any piece of plexiglass so there isn’t any build up on the sand paper. It’s basically the same theory of wet sanding a clear coat on a car. You can always sand the surface of any plexiglass to give it a “frosted” look. Toodle’s idea of getting a “formed” shape from a custom shop isn’t such a bad a idea but it’s going to cost you a lot of money because some shops bake the plexiglass in a oven. But you can achieve those nice smooth bends or edges with the heating strip or heat gun. Since you’re using somewhat of a thick plexi, it might take you a while to heat and bend it. I think 1/8" plexi is pretty sturdy enough to make a plexi box of any sort but that’s just my opinion.