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morganh2550
07-02-2009, 17:02
what is the most efficient way to cut plexi-glass

eugenebrooks
07-02-2009, 17:09
A table saw with a non-ferrous blade.

After that, a jig saw with some lubricant
to avoid melting from the friction.

Eugene

meastman
07-02-2009, 17:25
A band saw works too.

vivek16
07-02-2009, 18:26
If it's really thin plexiglas, I think you can score it and then carefully snap it. Look it up on google for more instructions.

parser
07-02-2009, 18:48
The same blades you use for wood will work well but, you can buy specialty bits to cut plexi which work really nicely.

ironbears
07-02-2009, 19:11
depends how much you care.

a carbide table saw blade works great for making strips.

metal bandsaw blade nice and slow works.

if milling it use a little coolant. just regular 40:1 mixture

if its polycarbonate scoring may not work

vivek16
07-02-2009, 19:15
If it's polycarbonate, you can use a jump press (I've only ever cut 1/16" thick polycarbonate on a jump press, I'm not sure how much thicker you can get before it doesn't work as well.

CraigHickman
07-02-2009, 19:37
I suggest with a properly applied cutting implement.

I'd love to help, but we need a bit more info. What thickness? What kind of cuts? What type of Plexiglass, or is this actually Polycarbonate/Acrylic?

thefro526
07-02-2009, 20:34
My Favorite way to cut plexiglass is with a table saw. I've done it with a vertical bandsaw and a guide to keep it straight but the plexiglass may crack if it gets too jumpy.

As for Lexan (Polycarb), a Table Saw is still best for Straight cuts and I Like a vertical band saw the best for any kind of a technical cut.

If you're in a pinch and you need to cut Lexan (polycarb) you can use a Circular Saw. I'd only cut this way as a last resort because it gets pretty dangerous.

RMS11
07-02-2009, 20:37
If it is thin, like 1/16 or smaller, shears work. They are slow but very straight.

Elgin Clock
07-02-2009, 20:41
Also, leave the paper backing on it while you're cutting it!!!!
This is important to avoid cracking/splintering for whatever method you use to cut it if you're using a saw type method.

If you're using a heated up piece of wire (which is possible for both cutting & bending - on a very low heat setting to avoid burning too much), then it would probably be better to take the paper off first.

Pumagrif
07-02-2009, 22:41
Leave the film on the plexi glass, use a small tooth ratio blade, and also cut slowly so it will not fuse back together.

Molten
08-02-2009, 01:23
Don't use a hand saw. I had to do that at a regional once and it was not a good idea.

Also, when you cut plexi with a power blade. Realize that the plexi will send off little fragments of the glass. Might be a good idea to have sleeves on when cutting. (Just make sure the sleeves can't get caught or anything.)

BurtGummer
08-02-2009, 03:58
We have been using jigsaws. Not the best, but they work. Gotta use coarse blades though, or else you will have melting problems.

NickE
08-02-2009, 04:38
A foot shear works well for 1/8" and thinner polycarbonate.
For thicker polycarb, a circular saw goes fast, but it splinters like mad.

Mike Betts
08-02-2009, 08:13
what is the most efficient way to cut plexi-glass

Although it has been hinted at in this thread, I wanted to be sure that you knew that Plexiglas is different than polycarbonate.

I know that the difference may appear to be semantic to us electrical types but it is important. If you hit Plexiglass with a hammer it will violently shatter whereas polycarbonate is so resilient that it is used in most saftey glasses you and your team wear in the pits...

The impact resistance of polycarbonate extends to tooling as well. Polycarbonate can be cut in a sheet metal shear, bent on a brake and drilled or machined easily. Plexiglas is not nearly as machinable.

My team always uses polycarbonate on our robots and we never use Plexiglass. This not only gives us a more robust robot but also increases the safety margin for the students working on the robot.

JMHO

Mike

Dick Linn
08-02-2009, 11:23
And a tip on drilling - you can break the leading edges on the bit to prevent them from digging in and grabbing. See http://www.hawkfish.org/snailman/acrdrill.htm If you can find the untwisted drill bits that are used in the Yankee type push drills, they serve a similar purpose. This also works for brass.

A few drops of water with liquid dishwashing detergent in it will help as well.

IndySam
08-02-2009, 11:52
Although it has been hinted at in this thread, I wanted to be sure that you knew that Plexiglas is different than polycarbonate.

I know that the difference may appear to be semantic to us electrical types but it is important. If you hit Plexiglass with a hammer it will violently shatter whereas polycarbonate is so resilient that it is used in most saftey glasses you and your team wear in the pits...

The impact resistance of polycarbonate extends to tooling as well. Polycarbonate can be cut in a sheet metal shear, bent on a brake and drilled or machined easily. Plexiglas is not nearly as machinable.

My team always uses polycarbonate on our robots and we never use Plexiglass. This not only gives us a more robust robot but also increases the safety margin for the students working on the robot.

JMHO

Mike

Mike I totally agree. I would never use plexiglas anywhere in my robot. I can get all I want for free but we still chose to purchase polycarbonate instead.

My company sells supplies for sign making. The reason I can get plexi free is because it is easily damaged in shipping and we always have the damaged pieces saved in our damaged goods rack. You won't find any polycarbonate in that rack.

Dick Linn
08-02-2009, 14:10
In a bind, Team 975 once used some of the "high strength" Acrylic. It was only moderately more durable than the regular stuff. No comparison to polycarbonate.

VEI Dude
09-02-2009, 09:19
Other than the table saw type stuff, we use a dremel with a spiral cutting bit (actually a Roto-Zip bit), with a straight-edge clamped to the material as a guide. Works very well.

BTW, don't inhale the fumes! Ventilate! :eek:

Cheers,
-Neil.

CPUgirl
15-02-2009, 22:48
We always use polycarbonate and always use our bansaw when cutting it. Anything else is much more of a pain the only thing are the little shreds that you have to deal with but if you make sure to keep your mouth closed and of course your safety glasses on (probably semi-long sleeves too) and you should be fine. You grow used to it. Good luck.

ZInventor
16-02-2009, 01:40
I've found that using a dremmel with a high speed plastic cutting bit works really well, as long as you have a steady hand.

it's also nice since it lets you carve complex shapes.

be careful though, the fragments sent off from the dremmel are EXTREMELY HOT, and if you aren't careful, your arms get covered in little red dots from the burning plastic.

also, WEAR SAFETY GLASSES, they will save your eyes.

-Z

millerm277
16-02-2009, 01:59
What we do: Big/straight cuts-Table Saw
Not possible to cut on a table saw-Band Saw
Too technical for either-Dremel, very slowly.

NC GEARS
16-02-2009, 10:51
As everyone has said, leave the film on it. Our team uses a band saw and a table saw to do it. Any detailing, such as rounding corners etc, are done with a dremel. Be sure not to overheat it so it doesn't melt. If at all possible, get some Lexan. If your using the plexi I am thinking of, then its an acrylic material. Lexan is a polycarbonate material that doesnt break very easily. We learned not to use acrylic the hard way. Good luck to you though!

Carlee10
16-02-2009, 11:53
Whatever you choose to do, do it very carefully!!!! I was working and unfortunately destroying plexiglass just the other day. You have to be very careful and gentle or it will break easily. I tried drilling a piece and cracked it, then was cutting another and managed to crack it,too. I was embarassed, and felt bad about ruining it. I won't be working with it anytime soon..... Good luck, though.

artdutra04
16-02-2009, 12:00
Whatever you choose to do, do it very carefully!!!! I was working and unfortunately destroying plexiglass just the other day. You have to be very careful and gentle or it will break easily. I tried drilling a piece and cracked it, then was cutting another and managed to crack it,too. I was embarassed, and felt bad about ruining it. I won't be working with it anytime soon..... Good luck, though.Next time use polycarbonate (Lexan). It won't crack unless you spill Loctite or acetone on it.

Carlee10
16-02-2009, 12:10
I'm not sure what kind it was, but i didn't know it was so breakable. I tried to drill it without a guide hole, and it cracked. so we got more, and i was finishing the cut, and somehow managed to crack it again, even though I was being really careful. and the covering was on it.

Dave Morris
04-03-2009, 00:03
Just use a jig saw and stay proud of your final cut line. Then use a hand held router with a bottom mounted bearing and clamp the plexi/polycarb to a straight edged countertop and trim it to final size. This easily works up to 1/2 inch thick if your router bit is large enough in diameter. We do this all day at work.

colin340
04-03-2009, 15:21
Mike I totally agree. I would never use plexiglas anywhere in my robot. I can get all I want for free but we still chose to purchase polycarbonate instead.

My company sells supplies for sign making. The reason I can get plexi free is because it is easily damaged in shipping and we always have the damaged pieces saved in our damaged goods rack. You won't find any polycarbonate in that rack.

this is the first thing a tell any rookie team

Team 135
04-03-2009, 15:34
Fast moving, fine tooth blade. Band saw is what we have used, we have also had luck with a circular saw.

charlie1218
04-03-2009, 21:38
We were hauling a piece of lexan into the new building (4x8) and we thought hmmm. lets test something. Secured a 0.5" thick scarp piece to it, went inside and asked a worker to drop a piece of rebar from the 3rd story. Didnt phase the lexan.

vivek16
04-03-2009, 23:34
I like doing a demo where I clamp 1/4" thick pieces of acrylic and polycarbonate to a work bench and wail on them them both with a medium sized hammer. The acrylic shatters into smithereens while the polycarbonate dents slightly (if you hit it just right on an edge). I think it gets the point across. :)

-Vivek