Robot Lifting

Originally Posted by gorrilla

Is noone thinking about getting on the platfrom from the bump?

IMO, any reasonable drive system will be able to handle that without issue. We're going to see a lot of systems that cannot, regrettably. It would be best to have the ability to get up no matter what area is open.

[viper110110]

we are currently thinking of some sort of arm idea with a winch assist. The arm alone will not be strong enough to pull us up, so the hook/clip we use will have a pulley system and we will winch ourselves up. The arm isfor getting to the pole first.

[gorrilla]

Originally Posted by CraigHickman

IMO, any reasonable drive system will be able to handle that without issue. We're going to see a lot of systems that cannot, regrettably. It would be best to have the ability to get up no matter what area is open.

Most 4-6 wheels drivetrain with a reasonably low COG should be able to, if they have the ground clearance, or seperate mmechanism to give them a boost...its only a roughly 6" step.

Originally Posted by bobosalad

problem with that is there is a lip from the bump to the tower, and geting centered on the bump isnt going to be easy anyways

A well designed drive-train should have no problems....

[Brett Elflord]

Here's a thought. Instead of trying to lift the bot from the very top bar, try lifting it from one of the side bars. It eliminates the possibility that you will get stuck in the tunnels while trying to lift up in the center. The only problem with this idea is the possibility of going side-to-side but with a world of engineers we can solve that.

[Kevin Sevcik]

Originally Posted by CraigHickman

IMO, any reasonable drive system will be able to handle that without issue. We're going to see a lot of systems that cannot, regrettably. It would be best to have the ability to get up no matter what area is open.

Originally Posted by gorrilla

A well designed drive-train should have no problems....

EDIT: I'm assuming we were talking about driving onto the platform from the bump. If this wasn't the intent then the following paragraphs will be sound confusing and be embarrassing for the poster.

I think you might be underestimating the difficulty of this task by just a little. Atleast if you're thinking of taking it straight on, straddling the bump. Consider:

If the bump was a 13.5" plateau as wide as your robot, you'd have a 7.5" vertical cliff in front of you to scale. A cliff of Teflon-like UHMW Polyethylene. Climbing it dead on is possible, but you'll need pretty sticky wheels to get enough purchase to get your front wheels up.

Of course, the bump's top isn't as wide as your robot. It's only 12" wide, so unless the inside of your wheelbase is 12", you'll actually start even lower and have an even taller cliff. Specifically, you'll have an inch more to climb for every two inches your wheelbase is over 12. Given that your bumpers start at a max of 11", the widest the inside of your wheelbase can be is 19". So all your reasonable drivetrain designers should keep their wheelbases reasonably narrow and resist the natural urge to make them wide.

So, I think climbing the platform straight on from the side is not something you can pull off with just a thrown together drivetrain. Now, I'll admit I haven't had a chance to look at how a bot could use the 45 of the bump to its advantage to get wheels on the top of the platform. It's possible that the correct approach vector will make the climb pretty easy for a multiwheel, very low CoM robot. Well, relatively easy, at any rate. I think you're pretty much certain to be pivot on 2 wheels for a fair amount of time during the attempt. Which is probably survivable for a multiwheel, low CoM robot. Which, unfortunately, doesn't sound quite like any reasonable drivetrain.

[MrForbes]

Kevin, I wonder if Craig is suggesting that a robot should be able to climb up on the bump next to the platform, then hoist itself up from the horizontal bar that goes over the bump edge of the platform. If so, it make sense.

Driving up the bump, then onto the platform, is not something that many robots will be able to do.

[Jon Stratis]

Originally Posted by amitz

Has anyone managed to lift 120lbs with a 2.5" CIM Motor & 12.76:1 gearbox (TOUGHBOX)?
By my calculations it should be able to do the job. However, in a test I made, it managed to lift only about 55lbs...

Tonight we lifted one of the mentors with a CIM and a (slightly modified) off the shelf boat winch. We used a dewalt transmission, however, with an additional reduction between the sprockets. It was pretty quick, with no issues.

Originally Posted by squirrel

Kevin, I wonder if Craig is suggesting that a robot should be able to climb up on the bump next to the platform, then hoist itself up from the horizontal bar that goes over the bump edge of the platform. If so, it make sense.

Driving up the bump, then onto the platform, is not something that many robots will be able to do.

Erm, yes, this. Apologies if I didn't make it clear, I an see how I mangled that.

Hanging from the floor is a much larger task than hanging from on a bump, but can be made simpler by using the vertical bars. Kudos to any team that can do a solid proof concept of it.

[amitz]

Originally Posted by eagle33199

Tonight we lifted one of the mentors with a CIM and a (slightly modified) off the shelf boat winch. We used a dewalt transmission, however, with an additional reduction between the sprockets. It was pretty quick, with no issues.

What was the ratio of the transmission?

[BryantWebb]

Originally Posted by Tom Line

I believe the difficulty hanging is disproportionate to the returns. Consider that if you didn't hang for those 20 seconds, you could probably get 1 more ball in the goal, rendering the hanging only really worth 1 point. Consider if non of your bots could hang, you could potential score 2 or 3 balls in that 20 seconds. Perhaps matches will be decided by a couple points, but this is NOTHING like 2007 where a single bot with a good ramp system could win 80% of it's seeding matches just by virtue of having those ramps.

The problem with scoring in the last 20 seconds is if your alliance has more than 2 points, you have 1 second to return the ball to play before you suffer a penalty. FIRST really wants teams to attempt to hang or elevate thamselves this year.

[EricH]

Originally Posted by BryantWebb

The problem with scoring in the last 20 seconds is if your alliance has more than 2 points, you have 1 second to return the ball to play before you suffer a penalty.

Wait, what? Where do you get this information?

The 11-second minimum is in constant effect. There is no way to get less than 11 seconds according to the algorithm.

[TubaMorg]

Here is the concept we are implementing to clamp a vertical pole.




Once clamped we will winch the back end of the robot up to the pole.
Initial tests are encouraging, though we will probably have a safety bar that can catch the platform to avoid sliding. Note the same mechanism that winches the robot also engages the clamp, using the robot weight to tighten the grip.

[Chris is me]

Originally Posted by TubaMorg

Here is the concept we are implementing to clamp a vertical pole

Once clamped we will winch the back end of the robot up to the pole.
Initial tests are encouraging, though we will probably have a safety bar that can catch the platform to avoid sliding. Note the same mechanism that winches the robot also engages the clamp, using the robot weight to tighten the grip.

Can you undo it by hand?

[TubaMorg]

Yes, a simple flip of the winch ratchet releases everything.

[bobosalad]

Originally Posted by TubaMorg

Here is the concept we are implementing to clamp a vertical pole.




Once clamped we will winch the back end of the robot up to the pole.
Initial tests are encouraging, though we will probably have a safety bar that can catch the platform to avoid sliding. Note the same mechanism that winches the robot also engages the clamp, using the robot weight to tighten the grip.

hey thanks for the picture, this is a great help of concept. Im just wondering if it can be transferred to a robot.