Robot Lifting
 

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.

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

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

Re: Robot Lifting
 

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

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

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

Re: Robot Lifting
 

5 seconds to attach and lift would make it worth doing. 20 seconds...not so much.

Re: Robot Lifting
 

Right now the plan is no winch, no cables... you will elevate us, and we will suspend you.

With a bit of credit to 1114's rack'n'roll design, we're looking at ramps.

It's still in the design stage, however, and if it doesn't pan out, well... winches work, too.

Jason

Re: Robot Lifting
 

I couldn't agree more.

Re: Robot Lifting
 

Has anyone considered a compound pulley system to lift their robot?

This would be considerably easier to build than a large gearbox, could potentially be lighter, and would result in less mechanical strain on the gears and axels.

Re: Robot Lifting
 

It would be beneficial for teams to examine alternate lifting methods. Why is everyone so focused on hanging from the horizontal bar, when there are four vertical bars that would work just as well with a smaller, simpler mechanism?

Re: Robot Lifting
 

I don't see the smaller, simpler mechanism I could employ to hang from the horizontal bars. I've thought about it and anything that comes to mind isn't easy to detach. Vertical hooks just slide over the bar and pull up.

Re: Robot Lifting
 

Would have to agree with Chris here. You can't really get much simpler then up, over, and pull.

Unless you could magically lift yourself up with a bag of air? :yikes:

-RC

Re: Robot Lifting
 

Add in the mechanism to get the hook up there, and you'll see where my concept of complexity comes from. I've been working on a design that literally has two hinges, and can hang the robot.

Edit: Bag of air?! Heck yes!

Re: Robot Lifting
 

Tension elements are the best approach for elevating, being lightest and strongest. Yes, you still need an arm to hook cable onto horizontal bar, but 1000 lb kevlar is light, and bar can be reached with the arc of a single arm rotation. Multiple long stroke air cylinders spreading pulleys apart in a compound array can give rapid cable tensioning lift to the required height, especially if you don't deplete your air reserves doing a pneumatic kicker.

-RRLedford

Re: Robot Lifting
 

After considering all situations that could happen in the last 20-30 seconds when handing will be attempted i came to the conclusion that it is best if 2 robots hang and one continues to score. This is simply because there will be potentially ungarded goals and more then likely 2+ balls in the scoring end, or a ton in the middle. If you have a good kicker it may be best to score even if you could hang. 2 teamates can easily hang off of the tower, any more and you have to hang off eachother. I think this will be a challenge and not all teams will be able to do this quickly. So if two teams hang off the tower and the third scores the team will have 4+(i would guess anywhere from 2-5 points) The other team will have from 6-8 if there whole team hangs. If 2 of the opposing team hangs then its even. If you run through all the senarios and make some assumptions you will see what i am saying. I think, but i may be wrong, that scoring with no deffender will be easy in the last 20-30 seconds (depending on when the enemy has to start hanging) and therfore it will be benifical to build the best kicker you can because if teams realize this they will want you.

Of course if no one builds a hanging bot then this doesn't matter.

My team is focusing on our kicker now and if we finish with time left we will build a hanging mechanism. This will give us time to practce while we build the hanging mechanism and then attach it on in the end if we decide to. I think this strategy will be great because we will then have a ton of driving practice, and the ability to do any task.

Re: Robot Lifting
 

We've looked into a system much like this; the trouble we're having is limiting degrees of freedom while elevating.

Re: Robot Lifting
 

Here is an idea that our team came up with that we believe would work and is outside the norm of lifting a robot that others may not think of. I was extremely proud of all of the ideas that the students generated this year for lifting. Besides this idea, they also came up with a great idea for lifting using the vertical bars. For the record, we are not using either idea. We are using the KISS method (Keep It Simple Students) and believe that we will have a lifting robot that can do the job quickly, efficiently and is simple.

I include this diagram within the spirit of Gracious Professionalism

Re: Robot Lifting
 

Neat idea! did anyone calculate the load on the winch? that low angle will make it pretty tough.

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That is a quite awesome idea.

I hope you guys make it work.

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That's a pretty sweet idea, i have to say.

There are some simple ways to get up the vertical bars (for example, clamp onto it with a wheel on each side, and spin the wheels. They'll naturally tighten onto the bar while they pull you up) - the problem we saw with using them is the amount of precision needed to get your mechanism arranged on the bar. I'm sure some team or teams out there will figure out a great way to take care of the precision problem... but we wanted to keep it simpler and fool proof.

So like many others here, we're going with a winch - it's simple, strong, and automatically locks to prevent being back driven. The innovative, and really cool, part is getting the hook up to the horizontal bar - that part takes under 1 second and needs, at most, a servo (we may be able to get the winch motor to work with it, eliminating the servo) in our prototype. It'd be nice to improve that on the real robot :)

Re: Robot Lifting
 

If the point about which your robot rotates up into place is within your FRAME PERIMETER, this does not work. The 3.25" bumpers will project through and below an imaginary plane at 20".

The idea is sound, but the implementation is tricky.

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I love it. Though I wonder how you get yourself pulled up so your bumpers don't break the plane of the PLATFORM, I guess I'll find out after Wisconsin. Good thinking!

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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...

Re: Robot Lifting
 

How did you try to lift with it? did you use a winch to wind up cable? if so, how big is the size of the spool that the cable winds on?

If it is too big diameter you will not have enough leverage.

Re: Robot Lifting
 

Yes, I have. the diameter of the spool was 1.5" by what I remember.

Btw, I'm asking if anyone managed to do that in order to be sure whether it's the motor's fault, or mine for not building the mechanism frictionless enough

Re: Robot Lifting
 

You'll need to lift 150 pounds factoring in bumpers and stuff.

I think your reduction is a little low... (i.e. not reduced enough)

Re: Robot Lifting
 

If you have some flat nylon strap you could try winding it on the toughbox output shaft to see if it can lift the weight. You might want to put another bearing on the other end of the shaft to support it though!

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That's exactly what I've done when I made that test.
But I did it with a piece of metal with a hole, that the spool goes in it. which may have created unnecessary friction.

Btw, thanks a lot for the quick replies. :)

Re: Robot Lifting
 

Well, in order to lift the robot you'll actually have to accelerate its mass, so you'll need more than 150 lbs. of force.

Also keep in mind that you'll need to calculate the output of the reduction at 1/3 the CIM's stall torque for max power. A CIM at stall will not lift your robot :)

You could add a chain or compound pulley reduction off of your T-Box to get enough force.

We found that a 70:1 reduction with a 2" dia pulley lifted the robot without tripping the breakers.

Re: Robot Lifting
 

Our idea was bungied Dual Telescoping Towers shooting up with crane hooks and a wench system with a cable strong enough to lift an elephant to pull us up and anyone who wants to hang on us.

Re: Robot Lifting
 

In '04 several teams used a bent fiberglass rod with a hook on the end and cable dressed to the rod with velcro. Rod is held bent by a servo or small pneumatic cylinder pin-puller. When released it snaps upward as it straightens to the right hight to hook the bar. Winding the winch raises the robot.

Re: Robot Lifting
 

Now that brings some interesting designs to mind :D

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this is the type of thinking we need, it may not work exactly as easy as sounded but this is what makes robotics cool and innovative.
if any teams come up with good ideas and prototype it, leave links for pics or something

Re: Robot Lifting
 

Does anyone have any alternate ideas that are really compact?

Also, I'd just like to point out that (1) you only really need to extend a little over thirty inches during the finale, cutting time considerably if you can extend to about sixty inches beforehand.

And (2), anytime you touch the tower during the match you can extend to finale proportions. That way a slower lifter could get up ten or fifteen seconds before the twenty second finale and still score. If you're planning on lifting other robots as well, this would give much needed extra time, especially if the first robot could get to the top just as the finale period began.

Thanks for any ideas.

Re: Robot Lifting
 

I'll have my team put some images up here if they're interested in sharing.

(1) assumes you're maxing out your height, and won't be able to drive through the tunnel.

(2) I actually like the idea of a dedicated lifter playing defence and moving to the tower early. It would make for an interesting strategy, with the possibility of points that cannot be defended against, due to the penalties surrounding lifting/hanging.

Re: Robot Lifting
 

Those penalties only apply during the 20-second FINALE.

Re: Robot Lifting
 

Yep. So as long as your bot can be in position before the FINALE, and can hang/hang others in less then 20 (or 15, for safety) seconds, you're guaranteed points for each match. Play defense for most, then go hang. Nice and simple, I like it.

Re: Robot Lifting
 

Hi, As I understand the rules the lifting is defined as "above the platform and in contact with the tower". It doesn't say the robot has to hang of the cross tube. So why can't the robot clamp to one of the vertical tower poles and pull itself up. It would not have to reach so far and also would not have to be concerned with the center of gravity wanting it to swing under the tower.
Frank

Re: Robot Lifting
 

That is perfectly acceptable if you can design a mechanism that can lock in place without damaging the tower.

Re: Robot Lifting
 

the hardest part of this is obviously attaching to the bar; how would you keep from sliding down the vertical tube?

Re: Robot Lifting
 

you have an arm that folds up past the tower, with a pivot above the platform. then you have a cross member at the tip of the arm and that is past the tower pole and a second on that is lower before the tower pole . If you then start retracting ( folding) the arm back it will clamp itself to the towerpol and the weight of the robot will lock it in. to support this function the crossmembers should have rubber surfaces.

Re: Robot Lifting
 

Like an adjustable
c-clamp

Re: Robot Lifting
 

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

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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

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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.

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

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.

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

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

What was the ratio of the transmission?

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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.

Re: Robot Lifting
 

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.

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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.

Re: Robot Lifting
 

Can you undo it by hand?

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

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

Re: Robot Lifting
 

This is such an elegant solution you should be applauded for thinking outside the box! The one problem I see is the 84in right cylindrical rule. if you make a 28" robot, and you'll have to assume your alliance partner is driving on it's 38" dimension that will determine the size of the platform on the vertical frame assembly. that accounts for 66". Since the rules state that the entire robot in it's finale configuration must fit within an 84" cylinder, I'm not sure you can manage a ramp long enough to allow for a 45 degree ramp angle to accommodate your alliance partner. You may have to do some fancy timed folding. I haven't looked at the numbers close enough so I don't know if that will indeed be an issue.

Steve

Re: Robot Lifting
 

Me and couple of my teammates had this idea that we call "wings". basically we thought of folded arms that unfold outside the robot and create 2 forklift-like platforms on both sides of the robot.


Our mentors said it's impossible and we're gonna break our wings on our first try.
what do you think?

Re: Robot Lifting
 

Nothing is impossible given enough time, weight, and money.

You'll have 150 lbs of robot 2+ feet out from your torsional point. So your ramps will need to support 300+ lb-feet of torsion. Not impossible, but not something to be undertaken lightly.

We were looking at holding to the vertical bar and flipping our robot upside down. At a lever arm of around 4 feet when the bot was horizontal, and considering the grab points on the bar would have been around 6 inches apart, you're lookin at over 1/2 ton of torsion / shear on the tower (and your gripper). Not something we felt comfortable engineering to.

Re: Robot Lifting
 

Someone did something similar to this in 2007. Granted it wasn't as high, but they made it work. I belive they way they did it was each "wing" was rotated up once the alliance partners were on them. Then a leg would pop down to hold the wing in place after power down. It was kinda cool to watch

Re: Robot Lifting
 

That's a lot like an idea I had at the beginning of the year. I'm not doing it because it takes a LOT of engineering to get it right, with almost no room / weight / motors for a kicker.

Re: Robot Lifting
 

Can you fit that inside the 84" FINALE CONFIGRATION cylinder? Your robot alone is about 34" (including bumpers). Your forks could only extend 22 or 24 inches on either side. Would another team take a gamble on balancing on a fork that wasn't at least as wide as their robot?

Re: Robot Lifting
 

THis is why we decided against the ramp/wings idea too.

Re: Robot Lifting
 

Ditto.
The idea came up, but the sacrifices to do it were too great.
If you could do it and still play the game for the other 1:40, it would be bennificial to the team.

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Has anyone found a good hook to order for getting onto the bar? Or, is everyone doing a hook just going to make their own?

Re: Robot Lifting
 

Spiffy, just buy a 1/4" aluminum plate from mcmaster and use a bandsaw to cut your hook out of it.

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At first, I was excited about this idea, but after some time I realized myself the problem -

3 words: Plane of Platform.

This system cannot be static, but if it lifts the ramps above the paltform's plane, no prob.

Re: Robot Lifting
 

you can get "wings" to work, we called them forks

http://www.chiefdelphi.com/media/photos/27790

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I'm not climbing on that.

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They got redone for IRI that year, less risky

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where did those platforms come from?

Re: Robot Lifting
 

they were oriented vertically for the majority of the match, then dropped down at the end.

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Some tips if you do try wings I learned from extremely simple and not very good prototypes:

1. With a robot roughly max width, you're just short of the max horizontal width on each side of the robot to fit in the 84 inch cylinder. So your forks would probably look like this:

------

------------

------

2. Strong materials and fixed joints are key to cutting weight down. Once the forks are to the sides of your robot, an in bumper way to "lock" them helps, or a way to raise them ~5 degrees then lock to help ensure sliding doesn't happen. You can make the forks fall by gravity with a servo and "snap in" to place if you want.

3. Make sure your hanging mechanism works even if you only have one robot on one side. There are ways to do this.

Re: Robot Lifting
 

what do people think about carabiners? well big ones! and what are peoples ideas for not getting stuck under the tunnel while trying to raise your robot up?

Re: Robot Lifting
 

Carabiners can be useful if your robot can apply enough force to make it stick there (for the spring gate to open, i mean).
If you don't wanna get stuck under the tunnel you can do it strategically by lifting the back of your robot before your front or mechanically by keeping your front bot in a curved shape or a straight one, without bumps to get stuck under there. Yes, i know, "what about the bumpers?!"... make some mechanism that will fall over your bumper to give your bot's front curved or higher than the tunnel.

for example:

#
####
#######
##########
############
##############
################
###>DEVICE ########
##################
##################
##################
BBBBBBBBBBBBBBBBBBBBBB
BBBBBBBBBBBBBBBBBBBBBB
BBBBB>BUMPER BBBBBBBBB
BBBBBBBBBBBBBBBBBBBBBB
BBBBBBBBBBBBBBBBBBBBBB

Consider this with your peers and Mentors... Good luck :]

Re: Robot Lifting
 

did anyone come up with an alternative to the CIM motors for some sort of winch climber? Were allready using all 5.

Re: Robot Lifting
 

FPs with a stock gearbox can work.

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FPs?

Not familiar. Do you have a pic/spec sheet?

EDIT: Fisher Price?

I found this on it:
http://www.usfirst.org/uploadedFiles...or%20Curve.pdf

Not sure how to read it though though (Im a programmer, leave me alone :P)

Re: Robot Lifting
 

Fisher-Price motors they are. Using the kit gearbox and a decent-sized winch can get a pretty fast but powerful lift.

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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?

Re: Robot Lifting
 

I need help with a question the hook we are building, the hook is build to a pipe thats 84in 1/2 O.D. Now my question is,which is legal? Like 84 inches to the ground or 84 inches from the ground to the pipe?

Re: Robot Lifting
 

Has anyone considered using a scissor lift mechanism to hang the robot?

Re: Robot Lifting
 

We had considered it at first, but then a few of our more experienced mentors brought up the size and weight of the lift, and how it would cause problems with the balance of the robot while crossing humps.

Re: Robot Lifting
 

yeah we considered it too but i think we are only going to use the scissor lift to lift the wench hook... just ideas. also what do people know about the cim shifter? is it possible to put a shifter in there without the second gear so it would be in neutral?

Re: Robot Lifting
 

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.

Re: Robot Lifting
 

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

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Better be careful wenches have feelings too :)

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you never wanna do anything fun....:rolleyes:

Re: Robot Lifting
 

Earlier people were talking about the fisher price gearboxes. How would you attach them to the winch?

Re: Robot Lifting
 

I'd use an octagon with a keyway or hex in the middle, cut to the size needed to fit into the FP's output gear. Then I'd use whatever attachment was needed to get to the drum.

Alternatively, I'd use a direct octagon-drum adapter to get it right on the FP gearbox.

Re: Robot Lifting
 

Question about lifting and hanging:

Rule <G05> States:Scores will be assessed after all objects in motion, when the ARENA timer displays zero seconds, come to rest, or 10 seconds after the timer displays zero seconds, whichever comes first.

Rule <G03> States:The TELEOPERATED PERIOD ends when the arena timer displays zero seconds. This also indicates the end of the MATCH.

And Rule <G42> States:ARENA Reset Delay - ROBOTS must release any portions of the TOWER, PLATFORM, or ALLIANCE ROBOT without power after a MATCH. Violation: YELLOW CARD.

So. When exactly does the robot lose power? Is it right after the MATCH, and so the robot would have to hang up to ten seconds without power? Or does the match end, then wait for all objects to come to rest or 10 seconds like Rule <G03> states, and then power is cut?

If you have any info that would be very helpful, this could be quite a problem for us!

Thank you much!

Re: Robot Lifting
 

Power is cut (or rather, the robot is disabled) at the end of the match (0 seconds left on the timer). Moving things have 10 seconds to come to rest after power is cut.

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so if you fall below the platform before 10 secs after the match it doesn't count. It hapened to a team a few times at cass tech.

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We -- who I am proud to say have the highest number of 'hanging points' after two weeks of regionals -- put a very simple mechanical catch so that when we were lifted all the way, we wouldn't come back down. The screw drive doesn't backdrive all that fast, but it *does* backdrive, so we had to be sure...