Here is Team 843’s 12 foot Canada Arm 3 just before it holds back team 652 from crashing through the wall.
How well did this arm design work? I had some doubts as to the Amount of leverage a robot would have over yours should it be on the other end of the arm. How well did it perform?
I really like the angle that photo was taken at.
Is that arm just for sweeping?
Just want to point out a flaw in robots designed like this. That long arm acts like a giant moment arm. Couple that with a robot that is usually top-heavy (most robots I’ve seen with a design like this are). These two things spell trouble if you encounter a robot that gets up to the ramp real quick and is high enough to “interact” with your arm. Those of you interested, check out the Midwest Regional’s first quarter final match between teams 16/65 vs. 71/167. The file name is il_qf4m1 on www.soap108.com
But look at their arm. It’s teloscopic. Unlike other teams, this arm is light and won’t tip over the bot.
Everyone elses arms are telescopic, they have to be.
Team 71’s arm was also telescopic. Materials used in the construction of the arm are negligible. What really counts is where the CG is, and whether or not the arm gives in case of a collision (as shown in the movie Kojib was referring to: http://www.soap108.com/2003/movies/il/il_qf4m1.asf)
Unlike most arms Cyber Blue’s flailer is not telescoping and it is quite heavy. In one match at the VCU Regional our flail did hit Metal in Motion during autonomous mode, and if I am correct our robot did not even move, let alone fall over.
I think it’s really a matter of how rigid the swinging joint is. When 71 got hit, the whole arm moved with 16, and caused Beatty to fall over. If the joint were to pivot when hit, however, such an arm could be turned with knocking the robot down.
Yes our robot was top heavy and we did fall three times but only in practice rounds. On our arm we used the battery to act as a counter balance so that our robot was more balanced than most robots with arms. we found out that if we drove up the ramp backward our battery also helped us from tipping over and by accident we turned out to be a really good king of the hill robot.
we have a simple drive train. 2 drills in low gear with a 3:1 gear ratio in sprockets. our tires were what made us so good on top of the ramp. we have 4, 3" wide tires with some really soft rubber that is really grippy. we had so much traction we had the dancing robot problem even on top of the ramp. we were on top of the ramp in every heat except one where we over powered another robot and went a little to far a tiny piece of rubber was hanging from our tire and that was touching the ramp. it took 5 minutes for the judges to make the call. if we had been 1 inch back we would have been on top of the ramp and got 75 QP’s instead of 3 QP’s which we got.
The Picture is one of the match where there was a robot fast enough to beat our arm to the stack. our arm actually over powered the robot and prevented it from crashing through in auton mode. although once auton mode ended it got another run at it and got through while we were taking another swing at the wall.
I feel that this strategy is one of the best. we also used our arm to reach over other robots to knock over human player stacks even when they were being guarded.
Even though we had a good working robot and strategy we still weren’t picked for the playoffs and that 3 point score in our last heat where we weren’t quite on top of the ramp dropped our average and blew our chances at getting in to the top 8. It was still a good year and i wish that we could go to another regional or the nationals but our school board has put a ban on out of country field trips. Looking forward to next year and thanks for all the positive comments about our arm.
Team Captain
843 WOW
it was quite a nice looking robot actually…
hi… it’s one of the ppl in blue tshirts across from u at canadian regionals… team 820… came 6th… yeah…
nehoo… it was a really nice looking robot u had there…
i just remember that one time the arm didn’t work as well tho… because someone had nudged your robot over during automous before your arm had the time to swing all the way over…
nehoo… it was fun at the comp
u guys did a good job tho
too bad the 3 point round dropped you so much…
i liked ur uniforms too, eh?
*Originally posted by Kojib *
**Everyone elses arms are telescopic, they have to be. **
Says who? 
http://www.chiefdelphi.com/forums/showthread.php?s=&threadid=18975
Go against the norm. 
I Think it was team 176 that had an arm like this at UCF this year. It did get flipped over one time but it used its arm to flip it self back over and continue with the match. I thought it was a great design. 
the only over the wall arm bot at ucf was team 147 deep thunder, unless i’m mistaken
Thats correct I think. I was talking based on (bad) memory. But after checking up, I find I was wrong. But what ever.
it was Deep Thunder, and they did not tip in the two matches we had w/ & against them… didnt hear about them flipping either, so i can assume they didnt. their arm also wasnt as fast as the other numbers ive been seeing w/ other arm robots, they are around our speed to the top at about 3.4. Those arms are impressive though
159 has an arm (that nobody really got to see much, we weren’t available for most of the rounds at SVR). And when we were able to drive, we tipped twice when our arm was on the side that the joint motors are on. But it wasn’t too much of a problem, re-righting ourselves was easy and the announcer guy loved it anyway. 
Roccobot 2k2 had two telescoping towers. You can use this design for ideas.