Recently acquired 2 sheets of transparent poly carbonate plastic thinking about making windshields for pull behind snow trailers so when I pull the kids don't get pelted with snow. These trailers will not be used on public snowmobile trails just around my property. So before I dive into this anyone bend or form polycarbonate successfully? Heating them and bending them without a brake? Mostly only have access to heat guns that I think will be beneficial for this project. Or should I build an aluminum frame and either rivet or bolt cut polycarbonate pieces to the frame? The tubs mounted to the ski frames are rounded, flared, and somewhat pieced together. Here's what I'll be working with and other ones similar. Ideas are appreciated.
Using polycarbonate for a windscreen?
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Mendonsy
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I have formed poly carbonate using a heat gun and a piece of tubing as a form. You don't need much pressure to bend poly but you do need to heat the entire bend area evenly. I also suggest that you don't try to do too sharp a bend radius either. Somewhere around a 1" radius is probably best to shoot for.
gstrom99
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Too late, since you already have the plastic, but... I've done something like this, but I used a windscreen from another sled, that was already shaped. Yes, even heat is needed (have a helper) to bend it w/o cracking.
etpm
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I have bent polycarbonate with a heat gun. I laid the 1/8 sheet over a 1/2 inch dowel and used a heat gun to gradually heat the area where I wanted the plastic to bend. It worked well. Before I did the job I was told by a guy who did lots of plastic fabrication to heat the polycarbonate quite slowly. The reason for the slow heating was because the plastic can absorb water and if it is heated too fast the water turns into vapor and the plastic ends up with bubbles in the heated area. So I just followed his advice and the bend turned out fine.
Eric
Eric
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Hopefully you got it filmed.
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jjeff
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Are you talking about it being "hard coated" it's not. I don't think the kids will mind to much if it gets a little scratched or discolored. Anyways a plans coming together, however execution of said plan is whole different story lol.
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No, filmed. I buy it in sheets with film on one side so you can handle it without unnecessary scratching.
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jjeff
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Yes it's got some film on it both sides mostly but someone else's discarded free junk is definitely not perfect. I'm thinking I'll lay down old towels and or cardboard under the sheets of whatever I attempt to cut, fab, and bend it on. Curious if I should leave what's left of the protective film on when I heat and attempt to bend it though?
civilian
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I would think leaving the film/protective material on during heated may allow the adhesive to melt into the poly with unwanted results. Just my guesses though. Have not done this. Jon
Creamer
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Yes. You want to remove the protective film before heating.
Renze
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I developed a slurry macerator for a company 8 years ago. I also built the exhibition model, opened to show the inner workings, running by a small hydraulic unit inside its pedestal.
I contacted my first employer, a maker of stainless steel restaurant and canteen kitchens. I remember they could laser cut Plexiglass. I said i want it to follow the curvature of the round housing, make the side hatches transparent. They said Plexiglass will shatter when you bend it, use Polycarbonate. We can brake press it in steps for you, just the springback is enormous and it might turn pale where you bend it.
So i had them brake press a 5 degree bend between the boltholes so it wouldnt gape at the beginning and end, inserted two bolts and just pushed it over till the other two bolts took thread, then tightened it up. Worked flawless, i just had to file dress the brown cutting edges from the laser cutter to make it exhibition neat, and the white discolouration of the brake press wasnt visible because the edges covered a galvanised housing.
In other words, if your window frame has enough rigidity you can just push it into place and bolt it down.
I contacted my first employer, a maker of stainless steel restaurant and canteen kitchens. I remember they could laser cut Plexiglass. I said i want it to follow the curvature of the round housing, make the side hatches transparent. They said Plexiglass will shatter when you bend it, use Polycarbonate. We can brake press it in steps for you, just the springback is enormous and it might turn pale where you bend it.
So i had them brake press a 5 degree bend between the boltholes so it wouldnt gape at the beginning and end, inserted two bolts and just pushed it over till the other two bolts took thread, then tightened it up. Worked flawless, i just had to file dress the brown cutting edges from the laser cutter to make it exhibition neat, and the white discolouration of the brake press wasnt visible because the edges covered a galvanised housing.
In other words, if your window frame has enough rigidity you can just push it into place and bolt it down.
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OP
jjeff
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Yep, have a shelf full of that series skidoo chassis parts unfortunately no spare windshields anymore (they do get pretty brittle with age and cold temps) I don't own a sheet metal brak plus I'm to cheap to buy a hundred dollar windshield for a 30+ yr old diy novelty trailer. Anyways when I get the time and it gets warmer I'll get the trailer pulled inside and mock something up with cardboard first than finalize my plan with that sheet of 1/4" thick sheet of polycarbonate I have on hand. I'm thinking it's going to be a combination of polycarbonate, and some repurposed aluminum angle and tube I have laying around. Thanks for all the input everyone
I'm still not completely sold on how I'm planning to mount it or cut it I guess for now Im planning to cut the sheet with a router bit and round off the edges with a router though?
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I have a local plastics supplier I use. I just send them a sketch with bends and dimensions and they fab up the part. I made a half windshield for my UTV that way and the cost was less than half of what a UTV windshield would cost online.
You can drill and mill the stuff easy enough but you need sharp tools. Get new bits if you want to minimize cracks.
You can drill and mill the stuff easy enough but you need sharp tools. Get new bits if you want to minimize cracks.
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Have you though about using two pieces off angle iron
and using a utility knife to cut/score for the break??
willy
and using a utility knife to cut/score for the break??
willy
chim
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We used Lexan at work for various things. One use was for forklift lids. We cut it to size and bent it with our large press brake (can do 10' pieces of 1/4" mild steel). The springback was substantial. 90° bends came back to nearly 45°. Cutting it is easy with a saw. While I haven't tried a razor knife, I'm doubtful it would work well. That's based on experience cutting Plexiglass. To cut it by scoring it you need to plow material out of the cut. One of the best tools - believe it or not - was from Kmart. It resembles this:
The tool is pulled and scrapes out a V, getting deeper on each pass. A razor knife tries to push plastic out of the way and doesn't work well.
My DIY cab had automotive safety glass except for the lower front where it had to be cut around the hood, heater lines and pedals. That ended up being Lexan after a misadventure with flexible plastic. Good material to work with. Below is a shot with the "crumbs" from cutting still stuck to it.
The tool is pulled and scrapes out a V, getting deeper on each pass. A razor knife tries to push plastic out of the way and doesn't work well.
My DIY cab had automotive safety glass except for the lower front where it had to be cut around the hood, heater lines and pedals. That ended up being Lexan after a misadventure with flexible plastic. Good material to work with. Below is a shot with the "crumbs" from cutting still stuck to it.
