Fans for defense

[RMS11]

Having driven against 1771 in 4 matches, with them in about 8, and watched quite a few others, usually their fans seem to help much more with maneuverability rather than pinning. They can make turns much quicker, but in this game pinning is really about positioning. You much kinda wedge your close to their trailer hitch and push at an angle. Other pins usually are fairly easily escapable, fans or no fans. Note the last qualification match of Palmetto, 21 shut down and pinned 1771 and their fans the hole match.
So in conclusion, I have seen fans effective to aid in turning and some acceleration, but dont make a huge difference in terms of pushing and pinning.

[Aren_Hill]

Originally Posted by Zflash

The fans had nothing to do with it.

and Third if you guys keep posting your different strategies on here people our gonna know what to expect.

Its a fairly simple equation, max pushing force of the drivetrain optimized through traction control, plus an additional 7lbs of force...

they will be able to push more than a normal bot theres not really much to argue

and i'm not gonna yell at him for posting strategies, lol

[Zflash]

It is hard to get out of a pin in this game, as I said we were not yet pinned while we were being pushed in open field. This is when it is critical to maneuver yourself away before getting pinned between two robots or a robot and a wall. The trick is to recognize exactly when you are getting pushed and to start turning out of it by turning your left side fwds and your right side backwards if you are getting pushed on th left side with your trailer behind you. We tried this when we returned to prove it, it is like pushing against a moving wall, and if the opponnent driver does not expect it, it will work. Sorry if I got the wrong impression, and obviously this will not work if you do not have enough manuvering space.

[Zflash]

Originally Posted by Aren_Hill

and i'm not gonna yell at him for posting strategies, lol

I hope I wasn't yelling..

[Aren_Hill]

Bug him for posting strategies would've been better wording lol sorry bout that

[Coley]

You guys really think he posted all of our strategies? lol you are mistaken unfortunately for you.

[martin417]

Originally Posted by Zflash

and Third if you guys keep posting your different strategies on here people our gonna know what to expect. I would be cool to see a team from the South even if you are on the "wrong side of the border" win it all but that will be more difficult if you don't keep some strategy up your sleeve. Good luck

As much as I enjoy winning, the reason I got into First was to share my experience and hopefully to teach some young people about engineering, as well as inspire them to pursue careers in that field. I understand that is the primary goal of First. If someone asks a question to which I feel I have a good answer, I will answer it to the best of my ability. If they then use that knowledge to create a more effective robot or strategy, then I have already won.

Remember, "knowledge shared is power squared" (not sure who originally said that).

[Zflash]

Originally Posted by Coley

You guys really think he posted all of our strategies? lol you are mistaken unfortunately for you.

I never said that he posted all of your strategies I just suggested that you all keep something to yourself. It is not unfortunate for me or my team because we will not be attending the championships thus we will not be competing against you again, that is what is unfortunate. I was merely suggesting to not post your strategies until the game has been played out, however you are more then welcome to do as you please. That is what is great about the United States of America ... free speech. By the way I don't think it is unGP to hold strategies to yourself, maybe I'm wrong.

[ScottOliveira]

I didn't see anyone post the obvious strategy as far as escaping a pin -> get your alliance partners to help! Teamwork pretty much always wins .

As for the original post, fans on defense, not only is it hard to make them powerful enough to be effective, but it is hard to angle them correctly. Any fan pointed at any angle other than parallel with the ground would change the normal force on the bot, which could cause it to be ruled a traction device in violation of R06 (I'm not 100% sure on whether it would qualify, but I believe I recall a GDC post about altering air pressure to increase traction, again, not 100%).

[EricH]

Originally Posted by ScottOliveira

As for the original post, fans on defense, not only is it hard to make them powerful enough to be effective, but it is hard to angle them correctly. Any fan pointed at any angle other than parallel with the ground would change the normal force on the bot, which could cause it to be ruled a traction device in violation of R06 (I'm not 100% sure on whether it would qualify, but I believe I recall a GDC post about altering air pressure to increase traction, again, not 100%).

It qualifies. There's one about using fans and vacuums to increase the normal force/traction characteristics.
http://forums.usfirst.org/showthread.php?t=11025

[ScottOliveira]

Thanks for the link Eric. Knew I had seen a post, but couldn't remember exactly .

[MikeReilly]

Not to slam a team that we pinned, whatever. I'll try to find the video of the match where our team was pinned by two bots, one on each side, and pulled out of it. That was cool.

[boomergeek]

Originally Posted by MikeReilly

Not to slam a team that we pinned, whatever. I'll try to find the video of the match where our team was pinned by two bots, one on each side, and pulled out of it. That was cool.

We used FP motors and followed 1771 recommendation on the nuances of the shroud shape: We could push any bot. We put our fans on a turret and varied them between 75% and 100% power in our final two matches. The fans properly used have a dramatic impact. I have no concept of how an expert driver could possibly avoid a pin unless she/he gets their alliance bot to run intentionally run interference: we were faster, more manueverable and could push stronger.

If I could start over, then I would recommend a 4 wheel drive train and at least 15 lbs of thrust from four fans on a turret. Turn it into Sumo bot wrestling. Easy pushes and excruciatingly long pins in front of alliance human shooters.

I might even throw in a compressor/tubing and solenoids to rapidly puff air to keep the traction wheels and the regolith in front of them free of dust to improve traction. Ball manipulation would be completely optional/superfluous.

http://www.chiefdelphi.com/media/photos/33618

[martin417]

I hope that no-one took my comments as a slam against ANY team, certainly not 1319. You guys built an awesome bot, and we enjoyed watching and playing with/against you at Peachtree and Palmetto. You guys were deserving of the quality award at Peachtree, as well as the judges award at Palmetto. I only singled you out as an example of using the added thrust of propellers as defense (the whole point of this thread). I still believe that the play in question was not the fault of your driver, or your robot. The added 6-8 Lb.s of thrust from the propellers gave our bot the strength and speed necessary to push a robot sideways all the way down the field.

[Zflash]

Good luck at the champs 1771.