Tips on cutting hole in Plexiglass?
 

Hoping for some tips from the RCM team.

I have a 1/4" thick piece of plexiglass. I need to cut a 1/2" hole through it. I have a hole saw, but it's rough-toothed.

Are there any precautions I need to take in order to not crack or harm the plexiglass?

Thanks!

Brian

Go slowly, and I would suggest some making tape on both sides extending a few inches past the hole.

Thank you for the tip! I read something about cutting underwater so it doesn't melt. I may try that as well. Thanks!

Personally I would want it as warm as possible, even use a torch to heat up the hole saw. Plexiglass is pretty brittle but when it's hot it's soft. If your hoping for a perfect hole....good luck!!! I'm sure the edge will be missing some chips

I have cut plexiglass several times and I would follow linc's advice. I would also use painters tape on both sides. If you use coolant, make sure you use water only as oils and antifreeze can distort the glass.

I just finished cutting two nice holes in the plexiglass following your instructions: tape on both sides, and slowly but surely. It worked perfectly.

Thanks for the tips!

No prob, never cut any that thick, but I have had good success with the going slow technique for just about any cutting chore.

I guess I'm a bit paranoid, but I used a couple pieces of scrap 1/8" thick plywood and sandwiched the plexi in between using clamps. I figured it would reduce any stress. Turned out perfect, but tape probably would have been sufficient.

i use a drill:intello:

Worked out.
 

Glad it worked out for you. Cutting plexi-glass is always a PITA. The tape method is about the best way to protect the project, and even that fails sometimes. Drilling very slowly is also a good technic but can be difficult depending on the type of drill bit used. A hole saw does not cause as much damage as you might think, and should go through the plexi fairly easy although it can leave the edges a little more rough. Plexi-glass used to be all the rave when it first came out, but the brittleness is really disappointing considering what it was meant to present in the way of durability. Lexan seems to be a much better choice. So what ya making anyway?

I'm modifying my son's wheelchair tray to accommodate a toy hanging arch I'm making out of PVC. It's not elaborate by any means, but I think he will love it.

I just cut the PVC, and I'll be bending it into an arch for the toys to hang from. This too is something I haven't done before, but it looks simple enough. Fill tight with sand, capping each end, hit it with the heat gun, then bend and cool. I'll be sure to post pictures when I'm done.

It's easier if you don't use a 118 degree bit since they tend to grab. It will work, but are you actually using plexiglass? I ask because a lot of people call every clear plastic plexiglass. For plastics I use 90 degree bits or for larger holes (1/2" or larger) use a Forstner but too keep it from cracking. We do lots of plastics from lexan to plexi to acrylic (the most difficult) and they work great on them.

Jeff

It's rough, but it's a first draft and will make him happy. Now I will just need to drill holes to hang toys from. I like it because it's removable for when he's not using it. I'll do a nicer second draft and get it painted up to match his cool red wheelchair.

Any thoughts on how I could improve it? I'm open to all suggestions!

http://i192.photobucket.com/albums/z...elchairToy.jpg

Thanks again!

He sure has grown since he got this wheelchair three years ago:

http://i192.photobucket.com/albums/z...DSC09765ed.jpg

Cool chair.
 

That chair looks pretty cool. Very modern up to date design. I like your approach of making up some removable items for his entertainment. They deserve whatever we can do to make their lives more tollerable. I would say a 9" DVD player that can hang up in front of him, that he can control and watch whatever he wants. Anything that gives them some sense of personal control is a boost for their self esteem, and confidence. Good move.

Nice work Dad! Here's a couple thing I would want on mine at that age. Beer holder. JK How about a fisher price steering wheel. To pretend I was steering it while we are out walking. Maybe a make shift review mirror so he can see you smiling all the time. I see those steering wheel they make for nintendo, sega, etc games at the thrift shop all the time for a buck or two. They usually have a setup to allow it to clamp the the table.

How about drilling a hole opposite of each other running a line across the brace. Then using a small quick hooks to hang the toys from the line. Could put one up above and one below. Then you could clip the toys to the line on the bottom one also (depending on the toy of the day) so they don't get knocked off the table. With the line and hook setup you could go overboard on the number of toys you have hooked on there vs drilling a hole for each line.


Maybe make a matt/picture to sit on the table that resembles a race track. Then hook up some hot wheel cars so he can race around the track. Hook a small line to the car because we know that he might not make every corner and that car would be on the floor more them on the table. The line will hopefully keep it in play and save you on bending over and getting it off the floor.


http://i212.photobucket.com/albums/c...uggestions.jpg


I got some of the clamps at K-Mart for .99 and Harbor Frieght had them for .49 a couple weeks ago. They look like the kind of hook a climber would use but not much bigger then a quarter in size.

http://i212.photobucket.com/albums/c.../climbhook.jpg


Drilling in plastics you want your bits to be rather dull instead of sharp. Basically the same thing Jeff said on the angle of the bit. The desired action is to actually scrap the material away instead of cutting it. Acrylic is a pain. I usually get all the holes made and on the last one the bit grabs and sends a crack through the whole thing. Fostner bits is what I use mostly for the more brittle plastics.

Your right your son sure is filling out his wheel chair better now. He looks happy.