Polycarbonate (LEXAN) Forming

[Vader]

Just an idea - maybe this is for the vacu-formers out there.
According to this, the properties of forming polycarbonate sheets (lexan) is not too different than ABS. I think it cools quicker, but that shouldn't pose much of a problem.

My thought is this - create a mold for the visor, possibly even the double visor, and form the polycarbonate over it. That way you get a more 'bubble' visor than using motorcycle visors. Downside is that as far as I can tell it only comes in clear. But the price is really good - a 4ft by 4ft sheet is only $25, and I think you could probably get about 4 visors out of that, maybe more.

I've only vacformed ABS (haircell), but I think it would work.
If anyone is familiar with this stuff, speak up.
I'm using Professional Plastics website (great company, very helpful and I highly recommend them). There are several options with the material. I decided that the General Purpose - Glazing Grade was fine for this application. You could go with the 1 inch thick bullet resistant stuff, but that's about 3 grand a sheet.
Thicknesses - .031, .062, .093, .125, .187, and up. I think either the .031 or .062 would be fine for this application. I have some .093 HIPS and it's pretty thick to use as a visor. Also, thicker means more expensive.
Type - Film masked or Paper masked. Paper masked may offer more durability during shipping, but it costs a little more per sheet.
Sheet size - anywhere from 12x12 (inches) up to 48x96 (4ft x 8ft). They will also cut your sheets to size. Very beneficial for shipping.

So thoughts on this?

 

[Vrogy]

Just an idea - maybe this is for the vacu-formers out there.
According to this, the properties of forming polycarbonate sheets (lexan) is not too different than ABS. I think it cools quicker, but that shouldn't pose much of a problem.

My thought is this - create a mold for the visor, possibly even the double visor, and form the polycarbonate over it. That way you get a more 'bubble' visor than using motorcycle visors. Downside is that as far as I can tell it only comes in clear. But the price is really good - a 4ft by 4ft sheet is only $25, and I think you could probably get about 4 visors out of that, maybe more.

I've only vacformed ABS (haircell), but I think it would work.
If anyone is familiar with this stuff, speak up.
I'm using Professional Plastics website (great company, very helpful and I highly recommend them). There are several options with the material. I decided that the General Purpose - Glazing Grade was fine for this application. You could go with the 1 inch thick bullet resistant stuff, but that's about 3 grand a sheet.
Thicknesses - .031, .062, .093, .125, .187, and up. I think either the .031 or .062 would be fine for this application. I have some .093 HIPS and it's pretty thick to use as a visor. Also, thicker means more expensive.
Type - Film masked or Paper masked. Paper masked may offer more durability during shipping, but it costs a little more per sheet.
Sheet size - anywhere from 12x12 (inches) up to 48x96 (4ft x 8ft). They will also cut your sheets to size. Very beneficial for shipping.

So thoughts on this?

Lexan is sweet, I've used it pretty extensively in robots. I've also seen some vacuum-formed parts for robots, including totally vacuum-formed exoskeleton frames.

Overall, it supposedly vacuforms pretty awesomely. Try it, tweak it, have fun.

Oh, if you want ready pieces, McMaster.com sells 2' square pieces, as well as odd sizes, etc.

 

[Darth Malevelus]

I was jus looking around at target, and saw a couple of potential things that could be off the shelf items that would be usedfor the MC visor, one was the clear bowl top used in electric popcorn poppers, the otheridea I had was using a couple of metal mixing bowls, use a third for the pieces, and make a positive, and negative sides, place a piece ofexanin themiddle covered in gold window tint, and cook it for a few at 400 degrees using big c- clamps to clamp it together in the oven.

There are two types of plastic, theflexible lexan type, that can be heated and reformed over and over again, and the plexiglass sheet called thermo setting plastic. This stuff canonly be heated andformed once, without splitting into pieces. Make sure you get the right stuff!

 

[Durlaburban]

i call lexan the POP plastic. you can bend it it and it "right itself" back to the vac formed shape and it makes a loud POP while doing so. My RC-10 GT's body is LEXAN and its a very durable plastic. When i Drag raced Randy's JATO maxxis with it i hit a street lamp. only thing untouched was the body. i was bent out of shape but then i just flexed it and POp it was a good as new. minus a few scratches of course lol.

 

[tonsofhoopla]

I've been trying to work out something like this for a while, similar idea, but the only thing i really ran into is the color.
You could just put the gold film over it but i don't like the results a whole lot.
IDK
-Justin

 

[Darth Malevelus]

I just hooked up a friend with a double visor setup using a face shield as the outer piece, and the remaining portion of the face shield was the section behind the first, the super thin face shield really hides it a double layered visor. and the face shield plastic redily adopts the shape of whatever its layed up next to.

I used self adhesive gold window tint I got from solargraphics, its the gold silver gold color. And it came out quite well. As soon as he gets his helmet completed Ill toss up a picture of it.

 

[NZTK]

the properties of forming polycarbonate sheets

Polycarb is fine for vacforming, but for the home user its not great, because it has a moisture content that needs to be baked out for a few hours before upping the temperature to make it droop, otherwise the surface can end up covered in dimples (like orange peel) this is fine with opaque stuff as you can sand and fill imperfections, but for something clear and reflective, it would ruin the surface. Though it dosent always happen, there are plenty of more user friendly materials