pic: Team 1717 Panel (alone)

[rsilverstein]

loading photo ...

Is that some sort of foam covered in aluminum sheeting?

[Gabe]

I spy foam insulation layered clad with aluminum... Am I right?

[whytheheckme]

Looks very sleek....

BTW, Congrats Gabe on ur 500th post!

Jacob

[rsilverstein]

Our robot has sandwich structure panels composed of 1.5" thick pvc-foam sandwiched between to .020 plates of aluminum held together by lots of gorilla glue (lots). We'll post more details on these panels later - the design is truly sick, they weigh around 20 pounds and can easily support over 200 pounds point-loaded each with less than a 1/4" of deflection; they're amazing and one of the things we are proudest of on our robot.

These aforementioned panels fall are held up by servos which release them; they are then pulled down by gravity. The panels then are extended 12" in each dimension thanks to fold out flaps (look at the pics we have already posted and the videos to come to see how these fold out). The dimensions are about 46" by 44" and have an area of about 2000" each and can easily hold any robot with no tipping issues at all and room to spare. These panels lock into the chassis of our robot upon falling.

The 150 lb. gas springs (4) are located at the point closest to the panels in the front and farthest in the back (look at the silver piston mounts in the pics) and each have a 16" throw. They are reverse-mounted inside of the previously mentioned aluminum housings to create a piston design placing the weaker rod of the spring inside of the housing and allowing the stronger casing of the spring to extend down.

They are restrained via an internal locking mechanism that comes stock with the springs we chose. This pin extends beyond the top of the housing and is depressed by a lever/cap... Each lever/cap is pulled - thus depressing the pin and releasing the spring - by four bike cables which are pulled by a leadscrew system driven by a banebots motor attached to the inside of the frame. Each spring/cable is individually tuneable, so we can determine when each spring releases and in what order. That being said, we chose to have the front springs release a split-second earlier in order to allow the other robots to roll back against our back rails to locate the robots.

Let me know if you have any more questions... we're glad to get the word out about these works of art.

[Ianworld]

Those platforms look quite awesome and strong. I'm very happy to see other home grown solutions to the platform material question.

My team also went with a very similar solution to the platform issue originally. I think we used the same foam as you(or something very similar) but instead of aluminum we used fiberglass G10 sheets and epoxied them on. The panels were basically indestructable unless you dug away at the foam insides or point loaded all the way on a corner. However we realized that we'd actually over the course of the construction process slowly made them heavier until they weighed more than aluminum honeycomb. So during our first two competitions we've migrated all of our foam-fiberglass panels to aluminum honeycomb panels. Its unfortunate but it was the only way to make weight and keep all of our functionality. The learning experience remains though. A bunch of members on the team now know way more than they probably ever thought they would about working with foam, industrial scale epoxy operations(don't fill a cup with a tiny bit of epoxy and a whoooole lot of accelerator ) and the properties of fiberglass.

That being said i'm really happy you've had great success with your composite. Its truly amazing stuff.

[rsilverstein]

We didn't have fiberglass available to us, and yes, weight was a huge issue.
The thin alluminum did pose a problem though, because although it wouldn't bend under pressure, it was so thin that anything that hit it, or scraped against it would cause a dent. One time when building it some kid dropped a skrewdriver on one of the panels and now it has a hole in it.
Oh well, it worked perfectly in competition.

Our major issue was to get the gas-spring release cables tuned correctly. At times the mount for the release got loose so they would deploy a little earlier or later. That was all fixed by our 2nd competition though

[EmilioM]

As for the honeycomb aluminum structure that was mentioned earlier - we tried a few iterations of the sort and were unhappy with the skin deflection that would occur at the unstrengthened portions on the panel. This foam-core design not only equally distributed those point load worries but also weighed less while minimizing deflection to an insignificant amount.

As for the dents and scratches Ross (rsilverstein) mentioned, the only negative effect those had was the loss of aesthetic appeal. Our mentor, who has a masters in material science, informed us that these dings and dents were actually GOOD for the panels as it further increased the tensile strength of the .020 aluminum facesheets which our panels heavily relied upon.

[EmilioM]

In the back you can see one of the aforementioned honeycomb aluminum iterations

[whytheheckme]

Originally Posted by rsilverstein

some kid dropped a skrewdriver on one of the panels and now it has a hole in it.

lol. Nice. Not "A team member" or "someone on our team".... just "some kid"

Jacob

[EmilioM]

Ya "some kid" and the funny thing is... Everybody on our team knows exactly who "some kid" is lol. He has this reputation - valid or not - for breaking stuff *cough* aashish *cough*... Aashish we love you.

[s_forbes]

Very sleek design, I like it! The size of your platforms make it one of the best lifting systems I've seen, and the unique materials really make it stand out from some of the other lifting mechanisms I've seen. Are you guys making it to Atlanta this year?

[rsilverstein]

Originally Posted by s_forbes

Very sleek design, I like it! The size of your platforms make it one of the best lifting systems I've seen, and the unique materials really make it stand out from some of the other lifting mechanisms I've seen. Are you guys making it to Atlanta this year?

Thanks for the compliments, everyone who put in long and hard hours on those panels all really appreciate it when others admire their work.

Unfortunately though (as you can see by my signature), we were only finalists in San Diego, not winners. So no, we won't be going to Atlanta this year. Let us know of the other lifting designs you see out there.

[EmilioM]

Thanks, we probably have the largest panels in the nation (at least that we seen/heard of) and the unique material you speak of is our 1.5" pvc-foam core design which is extremely rigid while also extremely light.

Unfortunately, we aren't. We twice lost to the Beach Bots (330 - an incredibly strong robot, look for them to go far in Atlanta) in the semis and finals in LA and SD; repectively. And both times we took the first of three games from them only to have them win the next two... Grr. Our only regret about not going to Atlanta is that we wont be able to showcase our unique design and reaffirm our feeling that we have one of the best lifting robots in the nation. To all those teams going to Atlanta - Good luck