Bottom stacker or top stacker ?
 

We are considering the problem from two basic perspectives:

1). We stack at the top. This gives you a robot like a fork lift. It can reach out and over things. Some of its challenges are stacking high and falling forward.

2). We stack at the bottom by grabbing an existing stack, lifting it 13", then placing it on an item on the floor (then repeat). You get a bot that resembles an engine lift. Its challenges are that it has to lift heavier loads an ultimately move them into place without them falling over.

Which would work better for this years game ?

Re: Bottom stacker or top stacker ?
 

2) This seems to support the Keep it Simple Strategy best.

Re: Bottom stacker or top stacker ?
 

Just depends on how you want to play the game and how well each mechanism integrates with the rest of your robot (drivetrain, other scoring mechanism, etc.). One thing to keep in mind with a bottom stacker is that you must have room to hold onto a box while you lift the others. Certainly not an insurmountable problem, but it may lead to some interesting frame designs.

Re: Bottom stacker or top stacker ?
 

1.) Allows you to cap off alliance members' stacks with recycle bins to multiply your points.

Re: Bottom stacker or top stacker ?
 

Yeah my money is with option 2. I'm sure you'll see a little of both, I'm not shooting down the first, but as ^^ said, :Kiss: Keep It Simple Stupid.

Re: Bottom stacker or top stacker ?
 

Engineering is all about trade-offs. As you have noted, both designs have advantages and disadvantages. The next step is to look at your strategy and determine which one will be the better fit. You may even find some kind of hybrid between the two that works best for your team. Don't forget to take into account what your team is able to accomplish in our limited build time!

Re: Bottom stacker or top stacker ?
 

The question is if you want to be able to stack totes or recycling cans. Would it actually be possible to use the same rig to grasp both containers even due to their differing size and shape??

Re: Bottom stacker or top stacker ?
 

Anything is possible, it is possible. That being said, if you can make your own stacks with totes AND containers, it takes away that task of having to place containers all the way on top of your ally partners stacks. You work. They work. Divide and Conquer.

Re: Bottom stacker or top stacker ?
 

It looks like there are many possibilities this year, since we have a couple different game pieces, different places to get them from, and different places to put them.

There are several other ideas I've seen and thought of that you didn't mention...such as stacking them onto your robot from either the top or bottom, rather than stacking them onto the platform that way. The totes can be right side up or upside down, and you can use this to let you come up with different ways to collect them, store them, and offload.

It boggles the mind. Have fun!

Re: Bottom stacker or top stacker ?
 

Yes.

one of the 3 day bots has built a template that fits into the side of both a tote and the handle of a bin. That solution is a top stacker.

For a bottom stacker any mechanism that "pinches" an object from both sides could be adapted to handle either.

Re: Bottom stacker or top stacker ?
 

some of the containers are going to be tipped over accidentally. Probably should have a container handler that can handle either way.

Re: Bottom stacker or top stacker ?
 

I think that Bottom Stacking is a great way for teams to get a lot of bang for their buck in actuations. 13" of vertical travel is much easier to accomplish reliably than reaching up 6 1/2" - both have the same upper limit for tower height potential due to the rules.
Top Stacking will be essential for big scoring - since it gives you much more freedom to build on the Stacks of other robots/add more than 1 Tote at a time.
I don't think that a Bottom Stacker will be topping the ranks (assuming it doesn't have other tricks up its sleeve) - but it's a slow and steady strategy that could be valuable.

Re: Bottom stacker or top stacker ?
 

The bottom stacker could work even better if one robot lifts the current stack and another pushes the next tote underneath it. This allows you to build up stacks starting with containers without too much lateral movement.

Re: Bottom stacker or top stacker ?
 

Bottom stackers seem more efficient to me, but the biggest drawback is that they can't help with cooperation as easily. Most designs for bottom stackers can't really accommodate for picking up totes from the step, and would also have difficulty placing on the step.

Re: Bottom stacker or top stacker ?
 

Not necessarily. A design that picks up totes from any part of the lip could easily interact with totes on the step and still lift entire stacks.

Re: Bottom stacker or top stacker ?
 

The more I read the more I want one of each in my alliance.

Consider a bottom stacker all alone in a match. That bot would go for the easy stuff first:
grab a container.
have human toss out a tote
stack
repeat tote stack until it has 6 or stack is too high to manage
move to scoring.

bottom stacker can do that pretty quickly, but it eventually has a problem: no more easy to get to totes ! they are all piled in the landfill. It now has to push them around somehow to get at them...not easy while carrying a stack.

Now imagine an efficient bottom stacker working with a forklift like top stacker. The top stacker can wade into the pile of totes in the landfill, stacking some, or just tossing them out for bottom stacker to grab hold of.

Re: Bottom stacker or top stacker ?
 

For option one you just have to keep in mind the fact that your robot cannot extend past 78 inches vertically at any time during the match. This means that no robot will be able to legally put a recycle bin on top of a 6 tote stack and it may be very difficult to stack a bin on a 5 stack of totes.

Re: Bottom stacker or top stacker ?
 

A robot actually does have room to put a bin on top of a 6 tote stack, but I'm not saying it would be easy.

Re: Bottom stacker or top stacker ?
 

There are 5.4 inches of space your robot may occupy above the top of a stack of six gray totes, or 3.4 inches if the totes are on the scoring platform and your robot is not. It is not impossible to use that distance to legally place a recycle bin on top of a six stack. It may or may not be difficult, but it isn't impossible.

Re: Bottom stacker or top stacker ?
 

Our team is prototyping both, and I would strongly suggest every team to try to do the same. I'm more of a proponent of a top stacker though, because I think the recycling bin is the most valuable game piece. Also, I think there will be a good number of robots able to make 3-4 tote stacks, but unable to cap them.

Re: Bottom stacker or top stacker ?
 

But is a 6' tall robot carrying a 7' tall stack of game pieces in violation of that rule ?

Last year plenty of robots perched balls onto their tall frames to shoot them, but they were not penalized.

Re: Bottom stacker or top stacker ?
 

If the game pieces are not part of your robot, it should not be penalized.