Tape measure anyone?
 

Hello,

Our team has thought up a (hopefully) genius way to elevate a hook to the top of the tower. We will have a hook attached to a tape measure. During the finale, we will extend the tape measure with a simple vex wheel, connected to a speed controller. Once we elevate the hook to the top of the tower, the hook will detach while the tape measure winds back up.

I want to know other team's opinions on this and its legality. The heavy duty tape measure extends 12 feet at the correct angle with three Allen keys on it.

Re: Tape measure anyone?
 

I remember some thoughts for teams doing this back in 2004. I am not 100% sure if one actually made it into competition. Do some searching around and I am sure you'll find it.

It's a creative idea if you make it fail safe.

Re: Tape measure anyone?
 

I know of a team that had one--851 (no longer competing), in L.A. It worked pretty well. Not sure what other teams used that trick. (Sure was fewer than in 2002, by all accounts...)

You may want to make sure of 2 things:
1) If your hook detaches unintentionally, can you retrieve it or otherwise get it out of the way? Better yet, can you prevent it from unintentional detaching from the robot?

2) You mention a VEX wheel connected to a speed controller for power to the tape measure. How are you thinking of powering that; i.e., which motor?

Re: Tape measure anyone?
 

I dont see anything illegal about it but I think you should test how much force the measuring tape can handle because you wouldnt want it snapping on you while you are elevated off the ground.

Re: Tape measure anyone?
 

Adam,
The thing to be careful of is the possibility of exceeding the FINALE sizing limitation. If the tape should fall over would it be possible for it to extend outside of the <R10> rules

FINALE CONFIGURATION
84 inch (213.4cm) diameter vertical right cylindrical volume
90 inches high(243.8cm)

Re: Tape measure anyone?
 

watch for the bending angle and breaking strength on the tape measure

Re: Tape measure anyone?
 

It will be a fisher price motor, but the winch will be powered by a cim motor. Thank you for providing an example of a team who actually used it and it will be fun to see you guys at the competition. Good luck!

Re: Tape measure anyone?
 

We have strength tested a heavy duty tape measure and it was able to hold more than 175lbs. Just be careful as you decide how to connect to the tape, putting holes in the tape can severely weaken it.

-James

Re: Tape measure anyone?
 

James,

I think Adam is proposing using the tape to deliver the hook (not to use as a winch) which sounds just fine to me.

Mike

Re: Tape measure anyone?
 

even with that the tape will bend if raised at a certain angle (we have all seen this)

Re: Tape measure anyone?
 

Patrick,

It may or may not work but it breaks no rules and does not seem to pose a safety risk.

I personally think that they can make it work and that it's a nifty idea...

JMHO,

Mike

Re: Tape measure anyone?
 

I wish I knew how teams got this to work without snapping. It seems so cool and would be just a touch lighter than the team's current hook delivery system.

Re: Tape measure anyone?
 

We also considered this idea, and got a prototype built, but we decided it would not be reliable enough for the robot. The tape can snap and fall, which would require us to pull it in and start again. Also, we were thinking we could use it as a winch and an arm, but it doesn't seem strong enough (directly, it could life >500 lbs., but any bending/attachment methods weakened it.)

By all means, however, go for it -- it is a much simpler idea than most, and could turn out to be a winner.

Good luck.

Re: Tape measure anyone?
 

851 did theirs inside a tube of some type (sorry, I don't remember all the details). It worked pretty well--they were the one team that got us off the bar that year! They ran the tube up with the tape measure, then pulled the tape down and used a winch to pull themselves up, IIRC. I don't remember if the tube came down or simply telescoped when the robot went up.