Cheap Tetras!

We all know that FIRST gave us some of the supplies to make up one of the tetras, but at $15 a pop for more, plus the cost of PVC, how many teams out there (especially rookie teams) can afford to shell out the money to make up more field pieces?
My team is in exactly that predicament, but we needed to make up some tetras to test our designs on. In steps the Team 134 Thinktank, who came up with the idea of using simple piping hangers to bind the pvc caps. These hangers come in rolls (sorry I didn’t get a picture of the roll), but it’s what a plumber uses to hang up the copper hot water pipes in your basement. It looks like a strip of metal, about the thickness of a penny and about as wide as a dime, maybe a little less than that. It has holes every so often, big holes, in an alternating pattern of big then small holes. You still need to use pvc and the pvc end caps, but you don’t need to spend the $15 for the nylon ends to build the corners.
I bought a couple rolls of this stuff at Home Depot in the Plumbing department for about $1.50 each. If you cut it at about 3", or after 3 big holes, it has just enough room to screw in a bolt at the same length as the distance between the holes in the pvc end caps.
Well, I’ll stop blabbering and attach the pictures I took of them.
If you have any trouble at all putting these together or finding the parts, send me an email at [email protected] or send me an IM on AIM at sessofiendjake. Enjoy, and happy stacking!

<edit> We tried making our caps out of the thick lexan, but they ended up snapping a lot, and that’s why we went with the plumber’s hangers. </edit>











Nice…we made our own connectors out of some thick lexan…I guess that saved us some money too…props to Jake for that awesome idea though… :cool:

We drilled some holes on the side of the ends of the tetra legs, and tied our tetras together with wire and/or zip ties. It works pretty well.

i like that idea… i’ll definitely have to mention it to my mentors since i’ve broken every single tetra we’ve made with lexan. :ahh: its not my fault… just… the lexan always rips in the wrong places. they’re not very durable (especially after being accidentally dropped a couple dozen times); even the tetra we made out of the clover pieces that came in the kit broke.

for the 7 ft goal in the center of the field, we had to measure and design special aluminum “clovers” that would allow the goal to stay standing… but even then that didnt work very well… and we resulted to using duct tape. (i’m sorry my explainations are bad… i’ll take a pic and post it sometime maybe as long as no one took it apart…)

kudos for the economical idea though. :slight_smile:

If you want to go even cheaper you could use parts from the edubot.

excuse my ignorance, whats the edubot?

IFI’s mini-robot thing. Used to be called “rapid prototyping kit” now its called the “robovation” kit. Not exactly cheap if you use the kits for other stuff, as the parts are more expensive than you would expect.

http://www.ifirobotics.com/edu-kits.shtml

If i recall, you used to get one in your rookie year?

Apparently the rookies could opt out of getting a Robovation kit this year and save the extra $. One of the teams I’m working with didn’t get/order one.

My Team made the tetras with PVC and PVC connection…
After, the Tetras was painting with blue end red.

There are very beatiful and cheaper!!!

Good Luck!!!

We were able to use a machine shop connection to get the end caps laser cut out of 1/8" steel plate, we just gave the guy the drawing and the machine spit them out, we then bent them ourselves.

The point being if you can get someone to donate them, metal will work just as well and free is always better than cheap :slight_smile:

Awesome idea. I used some scrap PVC sheeting, traced the clover about 20 times, and cut them out with a scroll saw. We heated them up with a heat gun, bent them into shape, and drilled the holes for the centers. It worked out alright but you may have to heat them up a second time to get them to fit without snapping. Just a tip for anyone else who needs one.

Mike F.
Team 1279- Cold Fusion