Robot Lifting

[bobosalad]

It is pretty obvious that people are spending a lot of time into the chassis, wheels, motors and even kickers. Well this thread is to bring attention to the lifting portion of the robot. I realize that a lot of people havent started that part yet, and i also realize that others have it made. Leave ideas, pictures, plans, problems, and everything you can think of about a device in order to lift the robot at the end of the competition. Thanks a lot.

[IndySam]

So far we have a Harbor Freight winch coupled to a AM 3 stage GEM transmission with a CIM that can seams like it is strong enough lift a small car

Eventually we will make a custom winch with the GEM but if we run out of time at least we have something.

[Chris is me]

Originally Posted by IndySam

So far we have a Harbor Freight winch coupled to a AM 3 stage GEM transmission with a CIM that can seams like it is strong enough lift a small car

I like it. I was thinking about using the 5th CIM with stacked GEMs for extra torque and it doesn't sound like such a bad idea.

I've got nothing else to show, other than that I've been inspired by the Pink team and the Poofs. I really have no idea how to do this. :3

[MrForbes]

don't need the torque so much as you need to slow it down

[Tom Line]

We had the shooter concept in 2 days. The chassis in 4. Just today we had a major breakthrough on a simple way to hang and we're cadding it to check feasibility. We've spent time in every meeting so far discussing hanging.

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.

Finally, the difficultly of suspending means that I doubt very many matches will see robots suspended. Even if they do manage to suspend, that extra 1 point *probably* won't be all that important: I certainly would not make it a design priority.

I look forward to someone building a bot specifically for the finale - there are ways to do it (twin ramps, lifting the other 2 robots on your team, etc). That bot could be a very valuable asset, but I don't think it's a game breaker like a good ramp bot was in '07.

[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.

[JHSmentor]

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.

how are you making the clamp engage the tubing? in the picture above, the actual weight of the clamp fingers causes it to initiall close around the cylinder. then as it is hoisted off of the cround the clamp sqeezes tighter - caused by the additional weight of the cyclinder itself. But - gravity is doing the work initially. For the robot, this mechanism would be verticle so you would have to initially get the clamp to squeeze a little around the bar before activating the winch and fully tightening it. I can think of some ways to make this happen - just curious if you have come up with something.

Also, is the plan to attach to one verticle bar or two? I am invisioning a system that would use two but I think aligning them for attachment could be very tricky given the type of clamp. Any thoughts on this?

[TubaMorg]

Originally Posted by JHSmentor

how are you making the clamp engage the tubing? in the picture above, the actual weight of the clamp fingers causes it to initiall close around the cylinder. then as it is hoisted off of the cround the clamp sqeezes tighter - caused by the additional weight of the cyclinder itself. But - gravity is doing the work initially. For the robot, this mechanism would be verticle so you would have to initially get the clamp to squeeze a little around the bar before activating the winch and fully tightening it. I can think of some ways to make this happen - just curious if you have come up with something.

Also, is the plan to attach to one verticle bar or two? I am invisioning a system that would use two but I think aligning them for attachment could be very tricky given the type of clamp. Any thoughts on this?

One method we considered was using a lead screw to attach to the pole. We have found, though, that the robot weight is enough to maintain a positive grip. We aren't done enough to drive yet, but we will be using V-type guides to align the gripper. Plus the gripper opens quite wide until engagement.

[bobosalad]

what about using the scissor lift to attach a wench hook and have the cable go back the the robot with a wench at the end, the scissor lift would not have to be strong enough to lift the robot

[RRLedford]

We are going for 3-5 seconds for BOTH cable attachment to tower bar using a latex tubing snap bar, and then fast elevation of our bot with pneumatic cable tensioning speed, having saved all of our air for the end game ( our kicker is a winder that stores bungee tension & releases at any point during the wind up for variable kick power). If you can't make this happen quickly there is little time left to help partners get off the floor. Yeah, the two points is marginal, but 5 or 8 starts looking worth it.
The initial pneumatic pull up will be supplemented by having more winder pulling available at a stronger than pneumatic force levels from our same kick winder mechanism. So, if partners can get hooked on to our deployed hanging Kevlar cables, even with a mere static hook at top of their frame, we can still hoist them up off ground using our kick winder drive pulling at 250+ pounds of lift. Heck, we will even loan them a hook to mount on their frame before the match begins!

-RRLedford