pic: REV Robotics Simple Lift



This is an example of a simple 3 tote lifting robot. It uses the sides of the wide version of the AM14U2 in conjunction with REV Robotics extrusion.

You can download the CAD here. http://www.revrobotics.com/building-system-applications/

Please note: This is not a complete robot model, so please don’t build it as is. The intention for these examples is to show teams how they might approach the problem and gain exposure to some COTS resources.

I like it. Doing simple things really well > doing a few things inconsistently.

This is a really good option for teams without a lot of resources. Being able to help cooperate will be very useful.

I would recommend lifting the stack and skiding the previous tote underneath it to increase stack height and decrease elevator size.

Could you expand on that? I’m curious where you are saying to slide the previous tote.

You take the stack you are in possesion of, lift it up, and move into another tote. Then place your stack on top of the new tote, and pick the whole thing up from the bottom again.

To clarify the tote stack lift:

If you lift the bottom tote in an existing stack, so long as your center of gravity is stable enough, you could move a stack of theoretically any height onto a single tote thus reducing the amount of height your elevator would require.

The trade off here is high loads and thus a more stable center of gravity is required.

I agree with that method of lifting totes. What material would be durable yet flexible enough for the snapping side pieces?

It could be rigid, but hinged and spring loaded so that it can only bend upwards.

Just wondering if there is any point advantage to stacking the totes within the robot, or if there is any real advantage to stacking the totes inside the robot in general?

Maybe being able to move stacks

Stability for one. Keeping your CG closer to your drive base should result in a more stable robot. Less tippy.

Stack security for another. It may be easier to design a system within your robot to keep tote/containers from falling over when moving about.

Greg,

Do you know if this was designed with one or the Bimba Cylinders that are available to us? We are mentoring a rookie team and this looks like a great option to get them started! Thanks!

COG. If your COG gets too far out the chassis (which, for tall stacks, is likely) then you risk tipping a litle bit when you accelerate or stop suddenly. If you tip even a little, you might knock over your totes.

Greg,

Do you have an approximate lead time for the bushings and bearing plate shown in this design to arrive at AndyMark?

Thanks!

I don’t know exactly what Bimba is offering for teams this year. The cylinders in this design are 1 1/6 bore 14 inches long. Technically anything longer than 13 inches should work, you would just be using more air per lift than you need. You could also put stopper blocks (pvc pipe) on the shaft to limit the stroke if only longer ones are available. The ones I used in the design were from Mcmaster McMaster-Carr

All parts are in route to AndyMark from Texas, I expect extrusions, plates, bushing and all the parts to be in stock by the weekend at the latest. We will keep doing our best to keep up with demand. We appreciate everyone’s patience with this, and if you have any questions I will always be available to help.

How far inside your robot is really a factor of how many totes you want to stack and what amount of control you want to have of the totes as you drive around. If you have them all the way outside your robot, making turns at fast speeds become problematic. The other reason why in this design I only did it half way (besides accommodating the Kit chassis) was to make it so you don’t have to drive on the scoring platform when placing totes.

Greg, I know you said it would be in to Andymark by the weekend, but unless I missed it, I doesn’t seem to be in yet. Any ETA or updates?

Extrusion did go in stock for a brief period yesterday but sold out in 6 hours. More is on the way and should be in late next week in a much larger qty. To be sure you get it this time you should click the “email when available” link on AndyMark’s Page.

We are committed to getting extrusion to teams as fast as our manufacturer and FedEx can move. The demand for the product has been higher than we expected due to the nature of this year’s game. We have arranged a considerable amount of product in the pipeline and think it will meet demand once it lands at AndyMark.

I did see it go back in stock (at a team meeting), but perhaps foolishly waited to see if other REV components would go back in stock only to see it out of stock the next day. I feel for you and the high demand you’re trying to meet.

Here is a video of a system like that. The pallet stacker lifts the stack of pallets up high enough to put another one underneath.

https://www.youtube.com/watch?v=xCH41Icgjoo