Uses of Lexan

[niklas674]

Team 701 generally use lexan for prototyping. We also use it for covers for pieces that do not need to be exposed like the top of our shooter where the gears are.

[Bill Klein]

Originally Posted by SeeleySWS

Our team built a lexan bender (toaster wire, plywood, wiring and hinges) and were able to make a lot with it. Our intake's guides were bent lexan, our upper electronics board was held up by bent lexan and our bridge that held our camera and shooter sensors was made of bent lexan. Good stuff! If you want to prototype you can use cardboard...

To add to Spencer's comment: The unit is portable (just a few lbs in weight without the battery) and is powered with one of our old 12 volt batteries. We take it to competitions and have assisted other teams needing a straight bend in their lexan. Simple and practical

[kaliken]

Originally Posted by Bill Klein

To add to Spencer's comment: The unit is portable (just a few lbs in weight without the battery) and is powered with one of our old 12 volt batteries. We take it to competitions and have assisted other teams needing a straight bend in their lexan. Simple and practical

Do you happen to have a picture of it or a diagram of it? Your bender sounds like a great addition to any team!

[Hitchhiker 42]

We used lexan a lot this year due to a lexan sponsor. A lot of our robot was clear including rails for the portcullis, actuators for the cheval, a belly pan for electronics, and the ball guidance system. I really like it as a material (it looks cool). For bending, we used a heat gun, which I don't recommend, but it was the only way.

[BrendanB]

We had great success using 1/4" & 1/2" lexan for out catapult. Its very easy to work with which allowed us to build our catapult during one of our events with our pit bandsaw.

[TAlholm]

I used to use polycarb or lexan as much as possible when making guards for components and other low stress structures. Although it didn't make its way onto 1991's robot, this past year I had made a sturdy scissor lift out of lexan and plastic bolts. I believe the weight of the scissor lift itself was between 1 and 2 lbs. Granted, the entire climbing mechansim was over 5 lbs.
Polycarb and lexan are very strong, and after talking with 4061 (I believe) at worlds, it makes a good amount of sense to use it for arms of an intake or other extending components. Mainly due to the flexibilty of the material, and unlike aluminum it usually goes back to its original shape.

(Just be sure to use lexan or polycarb, and not acrylic. It ends poorly if you try and bend it)

[Siri]

Originally Posted by inorbert

My team (5811) has a sponsorer who is a plastics manufacturer; they allow us to have any scrap material we want so we have a stock pile of lexan in our shop. Last season we used it as guide pannels for our intake and decoration. I was wondering if lexan (or other plastics) can be used for more stuctural components in robot build

We've used polycarbonate in a lot of ways people have already said to good effect, and it's likely the plastic you'll want in main body structural situations (if you want a plastic). But since you're talking about plastics in general, I'll bring up another one: polypropylene.

Polycarb certainly beats polypro in terms of most structural members and loaded applications, but that doesn't mean it's useless beyond paneling. It can take weight with the right shape and volume: you've sat in quite a few polypropylene chairs, and we love to use it for battery boxes in awkward places. It has good toughness and impact strength and is less dense than polycarb--the main limitation is its reduced stiffness. Still, that can make it great for some over-the-bumper end effectors. We used it for our claw an minibot deployer in 2011 (for a regional win as AC2). We rammed the polypro V straight into the minibot pole all season and got the claw bashed up and dragged around with no trouble. Other uses include drivetrain skids (for getting over bumps), game piece ramps (it's slippery), and flexible brackets and guards (nice when you need some flex tolerance). Basically anytime we're about to use polycarb we stop and think 'can it be pro?' since polypro is lighter by volume.

Other novel-ish uses of plastics:
I'm not sure anyone has mentioned pillow blocks, but depending on how your axles are loaded there are a number of plastic options. We've used acetal (polyoxymethylene aka delrin) for end effector blocks before. Really want to analyze and test your loads here, though. We've also used acetal for larger jobs, namely the white skids used to slide up the pyramid in 2013.

[Karibou]

Not exactly structural, but we used polycarbonate this year as guides for our conveyor (easier to see when zoomed in), which also served to center the ball for the shooter. We used a heat gun to bend the pieces and the distance between them when attached to the robot was slightly smaller than width of the boulder where the guides gripped it, so the ball was slightly compressed while it was being held there. The flexibility of the polycarbonate gave us a firm grip that hugged the ball really nicely. The guides were 1/4" at one point, can't remember if that was the final thickness used or not.

Other uses of polycarb on this year's robot were chain guards, CDF manipulator (linkages on the bottom of the intake), bellypan, sides of our winch spools, and the top of our conveyor (added to block the ball from flying up and out of the robot after being grabbed).

[Jonny_Jee]

In 2010, my older sibling tried to make swerve drive module housing out of Acetal Copolymer Delrin plastic. Unfortunately, it was never used in competition.

[Chief Hedgehog]

Originally Posted by IKE

I would recommend looking at and contacting someone from 1714:
http://www.thebluealliance.com/team/1714/2012

When I saw the thread, my first thought was to MORE Robotics. Incredible team that competes at a very high level every season - and the clear robots they produce are fantastic pieces of engineering!

[Oblarg]

Originally Posted by cgmv123

Obligatory reminder to make sure you're using polycarbonate/Lexan/Makrolon and not acrylic/Plexiglas/Lucite

To be fair, there's really no mistaking the two. Polycarbonate is nigh-indestructible and will bend easily, while acrylic tends to crack/shatter if you so much as look at it wrong.

[marshall]

Originally Posted by Oblarg

acrylic tends to crack/shatter if you so much as look at it wrong.

Boom!

[inorbert]

Thank you everyone for all the ideas and information, it is so helpful.

Sent from my LG-D851 using Tapatalk

[Bill Klein]

Originally Posted by kaliken

Do you happen to have a picture of it or a diagram of it? Your bender sounds like a great addition to any team!

Photo is posted. Thanks Rob Chapman for the pic and details.

https://www.chiefdelphi.com/media/photos/43953?

Search Youtube for "acrylic bender" and many tutorials come up. Most are 2-3 feet long and are attached to a variable power supply. Since we didn't have a variable power supply, however, the length was determined experimentally using our available DC voltage (12V robot batteries).

It's about 17 inches clip-to-clip.

The 20-gauge nichrome wire was sourced on eBay.

The circuit should be fused for 20 amps.

The one we made was modeled after this one:

https://www.youtube.com/watch?v=XveHMbzbyYQ

[kaliken]

Originally Posted by Bill Klein

Photo is posted. Thanks Rob Chapman for the pic and details.

https://www.chiefdelphi.com/media/photos/43953?

Search Youtube for "acrylic bender" and many tutorials come up. Most are 2-3 feet long and are attached to a variable power supply. Since we didn't have a variable power supply, however, the length was determined experimentally using our available DC voltage (12V robot batteries).

It's about 17 inches clip-to-clip.

The 20-gauge nichrome wire was sourced on eBay.

The circuit should be fused for 20 amps.

The one we made was modeled after this one:

https://www.youtube.com/watch?v=XveHMbzbyYQ

This is great! Thanks so much for taking the time to post this. I would think this could help out lots of teams.