pic: Team 3684 Robot in Progress

[dchartley]

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[asid61]

I very sincerely hope that you have the whole robot cadded and weighed at this point. Quadruple lead screw lifts will weigh a lot.
Also, your center of mass might get too far out with enough totes to tip you.

[GeeTwo]

Lead screws sound like an awfully low reduction if you're only lifting one GP with each motor. Though I guess since you're using four CIMs on your drive train, (neat-looking Killough, by the way), you're more limited on the lift motors. Are all four lifts going to operate on the same side of the robot? If not, that would keep your COG over the robot, though scoring would probably take half as long as picking things up.

[dchartley]

Total weight is looking like 110 lbs. The lead screw lifts aren't really that heavy and make up the frame of the robot. The layout is square and has a lift on each side. The lift fingers attach to trolleys on each lift and are removable to fit in the size constraints. We have had up to 3 totes and a recycling bin on one lift and it still won't tip over.

Doug

[asid61]

Originally Posted by dchartley

Total weight is looking like 110 lbs. The lead screw lifts aren't really that heavy and make up the frame of the robot. The layout is square and has a lift on each side. The lift fingers attach to trolleys on each lift and are removable to fit in the size constraints. We have had up to 3 totes and a recycling bin on one lift and it still won't tip over.

Doug

That's 110 with all mechanical and electrical + battery hopefully.
That's a prety good weight to be at.
I love the 4-lifter design, and when combined with an omni drive I can see this being really competitive. However, you might want to consider removing a lift and using the weight to add some kind of alignment mechanisum for totes; I think aligning the bot with totes could be difficult.

[nathannfm]

Originally Posted by GeeTwo

...you're more limited on the lift motors...

Not really, did you see the motor rules this year, 6 CIMs, unlimited everything else.

But it looks like they are using a window motor at the moment, which I do not condone. Stick a MiniCIM at the base of each one or something.

[smart1]

I think that's a pretty cool design. You could build 4 stacks at the the feeder station and carry them over to the scoring zone.

[pilum40]

We're using a 6' central Acme Lead screw with an anti-backlash flange nut to move our "elevator" up and down. Powered by a CIM motor via AM 90degree transmission. Works great. Fast, robust, no chains or cable to glop up during matches. Please don't ask for CADs, we don't have that capability on our team. We use Mark 2 eyeball fabrication methods, a good metal ruler and lots of patience. Some of us aren't as blessed as others. No whine...y'all remember that when you're walking down pit row being snarky about PVC, plywood, angle iron teams.