pic: 6 Stack Conundrum



Want to carry a stack of 6 totes? You’ll have to solve this problem.

15 lbs representative electronics (lower yellow area)
20 lbs representative front lift (vertical yellow area)
realistic drive train, with WCP gearboxes, 4 CIMs and battery in the very back.

45.4lb 73" red stack of totes.

Scale your ambitions accordingly!

Even if the robot was not designed exactly like this, does anyone worry about the axles on a west coast drive bending for the weight?

Not really. 7075 axles are actually really strong. They might bend if you jump them, but I don’t see them bending if you just load them up with alot of weight.

Cool, so it’s a really hard engineering competition!! How great is that!

And here everybody thought it was going to be stupid boxes moving around with dozers.

Love me some hard engineering problems…

This ‘conundrum’ makes the important assumption that you don’t have outrigger wheels to stabilize, a counterweight, or a way of taking the boxes further into your wheelbase.

Forklifts are designed to tilt the stack a little backwards.

I am not worried about the axle bending from the weight but rather balancing the robot. Jesse brought up a really good point which I haven’t really thought of, the weight shifts substantially when with and without totes. I’m curious to see if going onto the scoring platform with the totes would cause us to tip.

I really doubt it because our team keeps our old robots in a small room so when we have to get to the back of the room we just step on the chassis and none of our robots has a bent axle yet. I doubt 40 pounds is enough to bend a good steel axle.

The axles we use are aluminum, I believe someone mentioned that they’re 7075.

Good thing robots aren’t required to drive onto the scoring platform to score anything.

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Even if you’re being sarcastic, they indeed are not required to drive onto the platform to score the boxes on the platform. Particularly when picked up in this manner (from the skinny ends).

I’m surprised more on the plausibility of picking 6 up in a single stack hasn’t come up from a tote integrity point of view. One of the Ri3D videos had a good demonstration of the damage that happens to the bottom tote when multiple totes are stacked on top of it while it’s lifted by the single finger.

Even with 4 totes and a recycling bin the bottom tote starts to become bent and altered