for teams with arms
 

I hope you have planned for this.
http://www.freerepublic.com/focus/f-news/1308165/posts

Re: for teams with arms
 

LOL excellent! Even outriggers couldn't save them. Hopefully the crane operators where all right.

Re: for teams with arms
 

The last photo definitely looks photoshopped to me.

note to self: do not use robot to retrieve cars from water.

Re: for teams with arms
 

The last one is a mix of the 5th picture and one of the truck, but still hilarious

Edit: I was looking at this site


http://www.snopes.com/photos/accident/crane.asp

Re: for teams with arms
 

#9 is a photoshopped version of #4.

Re: for teams with arms
 

but still funny

Re: for teams with arms
 

Poor hatchback, LOL.

Re: for teams with arms
 

Actaully, most robots can pull a car quite easily, but only up a slight incline. Certainly not vertically. I bet a single CIM motor could lift a car vertically though if it has enough gearing. It would just take a while. It would take some sort of serious ratchet system so it didn't fall back down though.

Re: for teams with arms
 

Well let's just see here.... Your average Honda Civic weighs 2500 lbs. Assuming a pulley with a radius of 6 inches, you have 15000 in-lbs of torque there. At max power, the CIM puts out 10.7 in-lbs. So you'd have to have a 1400:1 reduction there. You can manage this geardown however you'd like, but it looks to be around a 6-7 stage transmission, so you'd have some fairly large efficieny losses, but we'll just ignore that. Your CIM's turning at 2600 RPM, so it appears you'd be lifting the car at a respectable 6 feet per minute.

For the bored and impatient in the audience, you can do this quicker with a straight energy calculation. Power = Force * Speed. Peak power = 337 Watts = 14913 foot pound-force/minute. Force = 2500 lbs. Thus, Speed = 14913/2500 = 5.9 feet per minute.

And the ratcheting mechanism wouldn't have to be beefy at all. If you put it at the first stage of the tranny, it only sees as much torque as the CIM does. Of course it'd have to ratchet at 2600 RPM, but still. You could put it a stage or two down, and it still wouldn't be that bad.

Re: for teams with arms
 

I realized that, but you'd want it at the end in case a gear broke or something.

One thing I've always wanted to try was to see if a lego motor could lift one of our full size robots. You would have to use non-lego gears though because the lego gears are quite inefficient and under that kind of load probably pretty prone to breaking. I was able to lift about 27 lbs with a lego motor (and all lego construction) It would have done more if the axle had not flexed so much and separated the gear mesh.

Re: for teams with arms
 

uhh.. kevin.. CANT TELL YOUR A MENTOR :D. . hehe.. good job explainning that one :D


yea.. and tahts a funny incident. :D .. stuff like that has happened before tho

Re: for teams with arms
 

Hey, it's a useful thing to know if your robot's lifting things. Like itself or something.

Re: for teams with arms
 

Re: for teams with arms
 

um yeah your thinking way to far into this

it would have turned out better if they anchored the second crane due to the fact that the way the crane is positioned the added weight of the water and car will throw the center of gravity off enough to tip it. All you need to do is counterbalance . Remember the solution is always counterbalance.

Re: for teams with arms
 

My reply was in response to whether a CIM could lift a car vertically. Also, the second crane falling in is almost certainly a fake. Also, also.... Yes, counterbalancing would have kept the first crane from falling in. So would the outriggers featured on the second crane, and they're lighter than a counterbalance. If you can get away with it, outriggers are probably preferred since they're so much more effective per pound.