Re: Propulsion that does not involve driving wheels
 

I'm pretty sure they'd rule that out as something with means to increase traction and therefore would be disqualified. Although adding lead weights on the top woulkd effectively be doing the same thing as far as interactions between the wheels and the surface so maybe there is an argument there.

Re: Propulsion that does not involve driving wheels
 

you could get around that by buying a off the shelf floor fan or something like it that comes with its own cage and just use its motor (might break a few rules unsure tho) or rip out the motor use the fan blades and cage and power it with CIMS

Re: Propulsion that does not involve driving wheels
 

I'd say the call is quite clear... this goes against the spirit of the rules, even if it is not explicitly forbidden in the letter of the rules.

Re: Propulsion that does not involve driving wheels
 

The fan on top pushing the robot down is definitly a question for the Q&A... While technically the fan would not be changing the traction, only the Normal Force, and thus the friction, it does get into the whole "lawering the rules" that is frowned apon. If they say we can do it in the Q&A then most certainly go crazy! But until then, it is kind of a dicey issue...

Re: Propulsion that does not involve driving wheels
 

I have to disagree. I dont see how it is against the spirit of the rules at all. The rule said you had to use the stoke wheels to support the robot, but says nothing about how those wheels have to be propelled. With fans, the wheels are the only thing in contact with the floor and that is 100% in the spirit of the rule.

Re: Propulsion that does not involve driving wheels
 

Oh, I think you misinterpreted me. The original idea of the thread, posted by Don Rotolo, with fans propelling the robot horizontally, sounds completely in the spirit of the rules. The idea of using fans in the vertical direction to increase traction sounds against the spirit of the rules. I think we really do agree.

Re: Propulsion that does not involve driving wheels
 

First of all, there are a lot of great ideas here. Thanks, Don!

Second, the idea of using a fan for downforce (either blowing down from above or creating a partial vacuum below) is Q&A material, but here's my opinion anyway: I think it's legal, as it doesn't change the traction devices - the wheels - but improves their ability to grip. The last sentence in R06 is pretty clear on its intent:

- Steve

Re: Propulsion that does not involve driving wheels
 

To SmurfGirl, I'm sorry, I did misinterpret you. I think using a fan vertically is still legal, but a little useless. Think of all the wasted space (if you wanted an efficient fan) and energy you would sacrifice! Why not just add weight bars!?

Re: Propulsion that does not involve driving wheels
 

<R06>ROBOTs must use ROVER WHEELS (as supplied in the 2009 Kit Of Parts and/or their equivalent as provided by the supplying vendor) to provide traction between the ROBOT and the ARENA. Any number of ROVER WHEELS may be used. The ROVER WHEELS must be used in a “normal” orientation (i.e. with the tread of the wheel in contact with the ground, with the axis of rotation parallel to the ground and penetrating the wheel hub). No other forms of traction devices (wheels, tracks, legs, or other devices intended to provide traction) are permitted.

A giant fan on top does not contact the ARENA, it's still the ROVER WHEELS. The other forms of traction are things other than the wheels that contact the ARENA.

Re: Propulsion that does not involve driving wheels
 

I don't think that you could use a fan as an effective defense. The shape of the game piece does not make it very resistant to air. Its also kinda heavy, not that heavy, but heavy enough to make it hard to stop.

Re: Propulsion that does not involve driving wheels
 

Don, you are psychic. I hope to see lots of great and waaaay out of the norm ideas coming into play for this game. There may very well be some classy, Newton-era type devices on display this year.

Re: Propulsion that does not involve driving wheels
 

For those of you saying that a downforce would be legal:

I'm 99% sure that it's not legal. The wording in the rule is clear: if it increases traction, it's not legal. The idea is to increase the normal force, which increases available frictional force (not friction), which increases traction. That's increasing traction, which is illegal.

The other 1% says to ask Q&A when it comes online and see what they say.

Re: Propulsion that does not involve driving wheels
 

a prediction: true or false.

"the use of a fan to increase the downward force the robot exerts on the floor will not be allowed if it exceeds 120 lb force."

you could weight or blow yourself downward up to 120 lb force. weight don't use batteries.

But the idea of using fans for horizontal propulsion even though that sounds cool would be noisy beyond description. It would bring the discussion on OSHA noise levels to a whole new level. It would create havoc on the noise front.

Re: Propulsion that does not involve driving wheels
 

i really wana see someone build a hovercraft or swamp boat :D

definitely going to be a great year

i think it would be legal (vert or horiz fan orientation) but i think Q&A would be a great way to figure it out

Re: Propulsion that does not involve driving wheels
 

I think the biggest problem with using a fan to propel a robot is safety. It takes a bit of work to get an FRC bot moving, and with a fan that sould mean moving as much air as possible as quickly as possible. This presents very real dangers to anyone near the field when debris on the field (or even a grain of sand) is blown into their face or body. It's a great idea, but too risky to everyone involved.