How Far Can You Bend Lexan Until It Breaks?

So, I am just curious, how far can you bend lexan until it snaps? I would like to use it as sort of a spring, but it will be the hood as well. So part of the hood, I will probably heat-form, but leave the other flat so that it is springy. I just don’t know how well it would work for fear of snapping. Keep in mind the lexan is only about 6.5" wide and most likely less than a foot long.

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This article on working with polycarbonate does not mention anything about a limit on bending it, so you should be fine. It does mention that you should initially bend it 20-40 degrees farther than you want so that would limit it. I only read over the cold bending though, I didn’t notice a heat bending part.

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I have been able to bend a 15” piece of plexi 90 degrees without any issue. It really depends on how long the piece is.
If you need to bend something smaller for a sharper angle I recommend using a heat gun and laying it on something that replicates the curve or angle you are looking for. Heat it up and press it on the surface until it holds that shape.

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All the companies make them differently… so bend it and figure out.

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it looks like @Dimension_360 wants to elastically deform the polycarb, so that it always springs back straight. I don’t think you can bend polycarb farther than around 45 degrees without it plastically deforming.

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seems like a good experiment for someone, how far can polycarbonate bend and still return to its nominal starting position. Record the results in your notebook for the judges.

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I know that if you bend a sheet of legally sized lexan to to degrees, it will spring back straight

I’ve tried snapping lexan by bending it before, I’ve bent it over tables, vices, hacksaws, and it just goes back to being straight.

Every. Single. Time.

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Hasn’t been my experience. Anything around 12 inches I can bend to a full 90 degree curve, and it always comes back true.

Yeah, this has been my experience as well.

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hmm I guess it depends on how tight the bend is. I think if it’s like a sharp 90 degree turn, it will probably permanantly bend, but if it’s like a 90 degree arc, probably ok.
I would be willing to bet that @Dimension_360 wants to use it for his hood, and I’d also bet that a hood shaped arc will be totally fine, as long as the polycarb isn’t bent for really long periods of time.

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This is what I am thinking, but there are lots of variables to consider with this.
I think for a hood it should be fine.

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Aren’t u allowed to heat lexan to aid in bending?

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Yes
(20character limit)

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Wow! jpearman is on my thread! I will definitely do that! From what I understand though, I shouldn’t have a problem at all heat-forming part of it and leaving one part unformed? Ok. Thanks!

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Yeah, that’s what I meant by this:

It’s personally my favorite way to work with plastic, but sometimes that tension and spring from bending plastic and holding it there can be useful.

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I would give you all likes, but I’m out for the next 8ish hours… :frowning_face:

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Well there’s a like fire you.
:slightly_smiling_face:

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Depends on the method of bending. I have used a hydraulic bender at our school and was able to bend successfully over 120 degrees. Pre-heating the polycarbonate will make the bending process easier.

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Each brand that makes it will bend differently of course, but I wouldn’t recommend using lexan as a spring. It would most likely change over time and using rubber bands would be more effective and consistent most of the time.

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There was actually a NbN robot in WV that used lexan as a spring to store and release the energy to shoot the balls. It seemed to work pretty consistently, not sure how often they had to replace the lexan though.

(but you’re right, rubber bands are probably better suited to most applications where you need springiness)

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actually, my intent is for there to be a trapdoor, and I will use the straight portion as the trapdoor. It will be pulled in TOWARDS the balls and the balls will easily move out of the way. I wanted to be sure the polycarb would be springy enough before I designed my whole drivebase around it (I am from a school club, so… with the current unfortunate circumstances… I don’t have any of the materials. That being said, I can’t test the springiness myself.

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