30-03-2010 13:23

cbale2000

Re: pic: 3280 Preparing to Hang (by tape measure)

I'm a bit curious as to how the hook gets up there in the first place, there don't appear to be any apparent mechanisms in the picture. Do you shoot it up somehow or have some kind of retracting hook arm?

30-03-2010 13:37

Ian Curtis

Re: pic: 3280 Preparing to Hang (by tape measure)

Ooh! That is interesting.

How did you spool the tape measure up on the robot end? How was it attached to the drum? I'm sure the solid tape was in no danger of failing, but I'd be worried about pulling out at the holes if it were riveted to the drum. Then again, I've never done load testing on a tape measure, and really don't have a clue how strong the stuff is...

Were you worried at all about a failure from being hit while you were in the process of hanging?

30-03-2010 13:47

JamesBrown

Re: pic: 3280 Preparing to Hang (by tape measure)

The tape it stiff enough that it is used as an arm, we drive the tape from a spool at in the robot and it extends to the proper height. An IR line detector stops the tape at the correct height. The hook weighs ~2oz, so it is light enough to not cause the tape to fold.

We have the tape attached to a spool, driven by a CIM through a modified kit transmission (Additional stage added). To allow the tape to feed out we used recirculating bearings around the outside of the housing for the tape so when the tape uncoils and puts pressure on the out side of the case the bearings roll and guide the tape out of the housing. The tape's tensile strength is plenty strong enough to support the robot (we tested it up to 240 lbs with out failure). We reinforced the tape with aluminum at the hook and at the hub where we riveted it. If the tape is already damaged and the robot twists while hanging then breaking the tape is a concern. To avoid this we added two spring loaded bars in the front of the robot to allow it to ride up the poles (they are clearer in the other picture) and we inspected the tape after use. We designed the mechanism so it is easy to swap the tape if necessary, the whole process takes ~5min.

I have pictures of the mechanism on my phone, I will post them after work.

30-03-2010 14:33

JamesBrown

Re: pic: 3280 Preparing to Hang (by tape measure)

Early testing video (poor quality) http://www.youtube.com/watch?v=jhdRaQZrORM Once the Boston regional videos are up I will link to a better video.

Close up of hanging mechanism http://www.chiefdelphi.com/media/img...5851ad94_l.jpg

30-03-2010 14:40

JamesBrown

Re: pic: 3280 Preparing to Hang (by tape measure)

Matches the blue alliance has posted that we hung in.
http://www.thebluealliance.net/tbatv/match/2010ma_qm37
http://www.thebluealliance.net/tbatv/match/2010ma_qm51
http://www.thebluealliance.net/tbatv/match/2010ma_qm57
http://www.thebluealliance.net/tbatv/match/2010ma_qm70

30-03-2010 14:40

TJ Cawley

Re: pic: 3280 Preparing to Hang (by tape measure)

that wasa very interesting idea. we thought about using a tape measure as a retraction mechanism for our robot's hooking arm, (once detached from the hook of course.) then we ran out of time and it was up to Mother nature and her gravity.

30-03-2010 15:08

Andy Baker

Re: pic: 3280 Preparing to Hang (by tape measure)

Hang on... I thought tape measures were illegal! (jk) Oh, yeah, this is not the 2002 competition*.

Seriously, this is a wonderful use of a simple mechanism. Kudos to team 3280!

Sincerely,
Andy B.

* - For those of you who were not around in 2003, there was a big controversy regarding tape measures as extension devices. Initially, they were deemed that tape measures were illegal, but that eventually changed during the competition season. I am sure that this tape measure mechanism will bring back wonderful memories for those folks who were involved in that discussion.

30-03-2010 15:11

JVN

Re: pic: 3280 Preparing to Hang (by tape measure)

COUGH2002COUGH

30-03-2010 15:12

Akash Rastogi

Re: pic: 3280 Preparing to Hang (by tape measure)

Team 3280 was a very impressive rookie in Boston. It is clear that we can expect great things from them in the future.

30-03-2010 15:15

EricH

Re: pic: 3280 Preparing to Hang (by tape measure)

Baker, you've been doing this competition too long. Next you'll be saying that the game with tubes was 1997*...

In all seriousness, that's an interesting way to use a tape measure, as well as an ingenious way to avoid getting stuck in the tunnel while lifting.



*It was, by the way. It was also 2007.

30-03-2010 15:53

Cynette

Re: pic: 3280 Preparing to Hang (by tape measure)

The tape measure lifter was definitely a crowd pleaser at Boston! Your team seemed to have executed it perfectly as well.

We would get that sense of anticipation whenever your team would take to the field with your tape measure hats. We had some guests sitting with us and it was fun to lean over and say, "just wait till the last 20 seconds!" And then after the lift was successful to tell them that you were a rookie team!

Great concept and congrats on your Rookie All Star award! I hope we will get to see you in Atlanta!

30-03-2010 23:14

larrysz92

Re: pic: 3280 Preparing to Hang (by tape measure)

wow very odd but unique! does it work? never seen that before! but anyways good job!