Tetra Manipulators

[n0cturnalxb]

Originally Posted by Aignam

If I learned anything from a late-night 1257 brainstorming session, it's that straws and tape work best.

awesome .. straw and tape prototypes, here i come!

... after finals week ends, that is

[Sachiel7]

One word:
Pole

[skillinp]

OK, say we choose one of these several designs mentioned, what materials would be good for it; i mean besides just aluminum, the obvious answer, would some kind of layering system be beneficial? like maybe 2 pieces of aluminum sandwiching some fiberglass, perhaps?

[Bernardo F]

Originally Posted by Tytus Gerrish

okay, this is personally my biggest concern. Designing an Appendage witch is Gracefully Powerful and proficient in handling the tetrahedrons. From the grabber mechanism to the arm Assembly or tentacle or whatever. What are your thoughts?

our team has a grabber that grabs UNDER the APEX of the tetra, can grab three tetras at the same time, then can be put up 12 1/2 feet, then telescoped another four feet.
I think. After that, CG is what we have to worry about.

[Rick TYler]

Originally Posted by Bernardo F

our team has a grabber that grabs UNDER the APEX of the tetra, can grab three tetras at the same time, then can be put up 12 1/2 feet, then telescoped another four feet.
I think. After that, CG is what we have to worry about.

Thirty pounds of tetras 12 or 16 feet from the ground (if I read your post correctly), held by an arm that has to weigh 20-40 pounds? Yeah, I'd do the CG calculations if I were you.

But if it falls over really dramatically, can you please post video?

Seriously, I expect to see a lot of robots s-l-o-w-l-y rotating to the ground, losing the CG war. I kind of expect to see some teams driving out from under their top-heavy bots. Let's see, applying a force at ground level underneath a structure 8 or 10 or 12 feet high, with a high polar moment of inertia...

- Rick Tyler
Old Guy with a Sticky Shift KEy

[Sachiel7]

I think we've struck a good balance with our arm. We've sacrificed being able to stack multiple tetras for speed. We don't shoot up our arm over 12 ft like many are trying, we are shooting for an arm height of 10.5 ft, which is great for our needs. We should (I'll post some video in a few days) be able to stack a tetra that is within 3ft of a goal, per se, onto the goal in (I'd estimate) 5 seconds (tops!)
This assists our strategy, which is focused a little more on the rows themselves, but still leaves the door open for quick loading of several tetras.
Our grabber this year is simple, as I posted above, we're currently just using a pole, probably with a divot cutout for the tetra to sit in (and rest on some digital sensors...)
We're probably just using some sched. 40 PVC, just like the goals. Perhaps aluminum, but I don't think there's really going to be a difference in our design.