Tetrahedral Tensegrity - an innovating sution for building vrc legal chassis

VEX Robotics Competition Discussion VRC
#1

Tetrahedral Tensegrity chassis is 100% vrc legal and innovative!

It may not get you TC, but it will make you immensely proud of your build.

vrc-legal-spacer-bot
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Steps:

  1. Get a pack of 1000 VRC legal Nylon Spacers from Amazon.
  2. Get 1/8" square steel rod and shaft collars from a local hardware store.
  3. Get 100 ft. of VRC legal 1/4" rope or paracord from your rock-climbing uncle.
  4. Find three old 4" omni wheels in the engineering room behind the bookshelf, where the freshmen team hid them last year when they lost the fourth one.
  5. Build the tetrahedral base, ensuring the rope is well taut and secured with zip-ties on the ends to prevent slipping.
  6. Go to a local VEX competition and enjoy seeing everyone jaws drop, while inquiring you what the heck they’ve just seen rolling onto the practice field
54 Likes
#2

Do you think it would be possible to build something like this in a traditional tank format?

11 Likes
#3

The trick to building this in real life is the custom ground corner and “pacman” pieces:

spacers1

After you get all the right angles on the corners and pretighten the rope, assorted “pacman” spacers will let you to taut it for extra rigidity and balance the length of the edges:

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Up next: custom sprockets and chain from cut up pneumatic tubing and unbraided rope.

29 Likes
#4

How are you planning to achieve optimal rope tension? The rope will likely require retensioning after a while as it will stretch out.

1 Like
#5

Spacers with a cutout on them so they can slip in, like the new clip on spacers in EXP

3 Likes
#6

With the “requirement” to custom machine a few spacers to pull off this design, I was wondering how polycarbonate might be able to be used to push this innovating solution to the next level.

Maybe polycarbonate sprokets or gears could be a good soultion.

4 Likes
#7

This is amazing! Sign me up!

1 Like
#8

Just like @OrangeMan said, I’ll use “pacman” spacers.

My “custom machining” was done with utility knife and hammer and then a bit of drilling and grinding with a dremel.

That’s a great idea! @Sylvie?

Yes, I think it is possible, but I find aesthetic beauty of the tetrahedral design irresistible for the first prototype.

Actually, the idea was to make this type of build possible for teams with very constrained set of tools and budget, so they could get cheaper parts. Later I am going to reply on my Chief Delphi topic, where they had questions, why I think this choice of material and shape was optimal for competitive robot, over solid steel bars or Stevonator type chassis.

11 Likes