Turbulence

[greencactus3]

Originally Posted by Tatsu

We talked about this, the best way would be to get a commercial leaf-blower and gut out the insides, replacing the motor and creating a compatibility gearbox.. you'd get something like 220 mph winds upward..

if so.. think more Normal force..... =..... unpushable robot?
actually i think its impossible to get a 220mph air current...... i dont see how you got that number.

[Zach Purser]

Has anyone tested using a leaf blower to launch the balls? Most people report the balls as being just under 7" so you could feasibly use 7" ductwork as a cannon. Creating a sealed system might be a little more tricky.

As far as feasibility, I don't think you'll get 200mph, but it seems that if you attach a globe motor to a blower you'd get a pretty good amount of air. Maybe the results would be similar to this blower:
http://www.makitatools.com/menu.php?...et&tag=UB181DZ

If anyone could dig up a spec sheet on the motor in this blower we could compare it to the kit motors.

[I'mwithstupid^]

how does using suction take up an more power than blowing???????? the air that comes out of the blowing end had to come from some where! so if it shoots out of a collar at 220 mph, if u switched the direction of the rotation of the fan than it should suck at the same speed.

[Alekat]

Originally Posted by I'mwithstupid^

how does using suction take up an more power than blowing???????? the air that comes out of the blowing end had to come from some where! so if it shoots out of a collar at 220 mph, if u switched the direction of the rotation of the fan than it should suck at the same speed.

I assume with sucking you'd want to grab the ball for yourself. With blowing you only wanted to knock it off course. The robot hopper is a much more specific location than "anywhere but the goal". And even if you could pull the ball into your robot you need even more power, or less simple design, to keep it there. i can just imagine the ball bouncing off and going into the goal anyway

[Tatsu]

220 mph is the leaf-blower I own.. thats where I got that number.. I think if you use 2 of the big CIMs, and create a gearbox, that number might be feasible .. but of course I suspect this will drain the battery faster than any other design.

[Arkorobotics]

You know how pneumatic wrenchs work? why not do that? get the pressure from the pneumatic tank and input it to a mini fan that extends out to larger propellers.

[lukevanoort]

I thought of another benefit of sucking. If you blow then your column of air will invariably point towards the goal, unless you're off to the side. So, if a team gets a ball in the column they score and you look stupid. So, maybe this should be an offensive strategy.

[mechanicalbrain]

Originally Posted by lukevanoort

I thought of another benefit of sucking.

I don't think sucking air would be nearly as efficient as propelling it. When air get pushed out it looks like a mushroom (I know not exactly but thats as close as i can describe). When sucking air however, air from all around will rush to fill the vacuum. Hardly something you can aim, think how powerful vacuums are but how short their range is.

[Alan Anderson]

Originally Posted by mechanicalbrain

I don't think sucking air would be nearly as efficient as propelling it. When air get pushed out it looks like a mushroom (I know not exactly but thats as close as i can describe). When sucking air however, air from all around will rush to fill the vacuum. Hardly something you can aim, think how powerful vacuums are but how short their range is.

The concept used to explain what you're talking about is "entrainment". Blowing air will drag more air along with it, moving a lot more than just what the fan is capable of. Sucking air doesn't get the same benefit.