"lifts" for nothing but net

VEX Robotics Competition Discussion VRC > Nothing But Net (15/16)
21

When I was wandering around Kentucky Kingdom, I thought how awesome it would’ve been if Karthik gave a shout-out to the anti-gravity motors from a few years back during the game unveiling: We’re betting that many of you will be wishing for anti-gravity wheels this year.

Anyway, I don’t anticipate many robots using motors to lift other robots - it’ll be passive and we MIGHT actually see robots go to worlds without using all ten motors!

22

I have discovered a truly marvellous design for this, which this post’s margin is too narrow to contain:

23

Is that all we have to build? Piece of cake…

24

I must start it…

Do you even lift?

25

Presumably any good robots would be made light this year, though I will strongly reinforce the C-channels that hold up the robot (which will be steel on an otherwise-aluminum robot). I’m also considering contracting my wheels into the robot with pistons when elevating partners so the chassis can support their robot and my axles won’t get bent.

26

Actually, kidding aside, after reading many good posts in the last few days I came to conclusion that there are two optimal (and one crazy) strategies:

  1. Have the other robot provide you a “shoulder” of the same height as the field perimeter. Then your robot will push on the partner and the field perimeter to elevate itself up. Getting to 4" should be easy, 12" is more challenging.

This strategy should work much better than sitting on top of the other robot because all you need to find is a single point of support. You can design your robot to be heavy on the perimeter side so it should work even with weak clawbots.

  1. The second strategy is for cooperating robots that are willing to place an attachment point (a hole or a loop of some kind) on top, right above their center of mass. Then your own robot will hook them up and lift to 12" or higher (just like cranes in the picture) :slight_smile: This strategy seems to be more reliable at getting to 12" if done correctly.

Added benefit of this method is that you do not need to be pressed against the wall and, theoretically, you can keep shooting driver preloads while the partner is trying to hook himself up (or vice versa). Also, it should work even if the other robot is dead. This makes sense during qualifiers, but if your partner dead during elimination rounds you are likely toast anyway.

  1. Finally, the uber-crazy strategy, which was suggested by someone earlier, would be to have both alliance robots to link-up and elevate themselves at once. If Karthik rules this legal and somebody pulls it off - he should give them dual headed VEX trophy! :D:D

I am inclined to build #1 and will think hard about combining #1 and #2 in the single robot.

27

Currently, I would assume, based on the rules, a double elevation is legal and worth 2x 25 or 2x 50 points, as all criteria are met by both robots. However, I hope that the rule won’t be updated to prevent this, as it would prevent a very difficult but amazing design.

28

I’m a bit confused with some of the talk of using the field wall to lift oneself. Are you allowed to grasp the field wall in such a manner? Wouldn’t that pose a risk of damage to the field and therefore be illegal?

Also, even if you can use the field wall, you cannot be outside the plane of the field wall for the elevation to count. So is the plane of the field wall the outside or inside of the field wall? If it’s the inside, you can’t use the wall in any way and expect the elevation to count. If the plane is the outside I would still find it unlikely a robot could use the wall to lift without being outside the plane of the wall at all.

29

The main problem with elevation are all the unknowns of your partner’s robot. There may not be an ideal spot to attach a hook and they may not be the right height or have the right surface to be able to support you as you lift off the perimeter. I personally think the best bet is to try and design a universal elevation mechanism such as some type of platform or ramp.