How can we drive on this new floor?

[gorrilla]

Originally Posted by Dracco1993

I still need help on thebluealliance thing please.

try here
http://www.thebluealliance.net/tbatv.../teambadge.php

[ScottX]

haha its like a car on ice...=D

[NorviewsVeteran]

Originally Posted by ScottX

haha its like a car on ice...=D

Obviously you don't drive the robot.

[PowerOfKings]

So Zyck_titan it seems you had the same idea I did... >.< and I thought I was original.

We did the math and with a 480 watt (the maximum wattage motor allowable) you could produce just under .2 psi. (allow variance for rotor blade type) Numbers for this were taken from a website publishing the Static Pressure capabilities of their 480 watt fans. (we then did conversions to psi)

Now you have to multiply by the square inches (maximum allowable 1064 = 28x38) and we get about 213 pounds of extra force.

So if you had a skirt around the entirety of your robot you could conservativly expect to roughly double the weight/normal force of your robot. (you'd lose a lot due to inefficiencies)

This means that when applied to F=MA in regards to your acceleration you can expect to take it from roughly .6 m/s (static friction with no fans) to 1.2-1.5 m/s (static friction with fans)

Now logistics might be a tad tough but hey if it gives you double your friction then it's worth it in my book. The real problem... ripping up the play area. If it isn't secured you would just vacuum it up and be completely stuck. This seems a real problem to me since when you look here ( http://thebluealliance.tumblr.com/po...field-elements ) at the end you can see the edge of the field which is merely secured with TAPE and now if this is a thin linoleum style roll you would just suck it right up and then... you wouldn't be able to move and might even get a penalty for destroying the field.

...after further research ( http://www.frpshop.com/pdf/installat...structions.pdf ) assuming FIRST followed these rules for the construction of a gasolenar frp floor it might not be too much of a problem...

[Koko Ed]

Alot of people's response to this problem reminds me of an exercise we had to do at a workshop that work had us do to advocate thinking outside of the box. They had us put up our hand and the guy would push it. Of course out of reflex we would resist. And he asked us why we resisted? Because it our habit to do so. Sometimes instead of just resiting the forces that are working against you is to loosen your control and work with those forces and allow them to do the steering.
Seems to me what people have the biggest problem here with is being in complete control of their robot and are trying to come up with every possible solution to regain that control when maybe the best solution is to embrace the lack of control and use it to the advantage like the guys who suggest the drifting training. You could waste alot of time and energy otherwise.

[Dracco1993]

Some of my team members and I calculated that using 2 sim's and suction cup properly you caould add an extra 600 pounds to your robot with ever touching the ground... Any Ideas?

[Koko Ed]

Originally Posted by Dracco1993

Some of my team members and I calculated that using 2 sim's and suction cup properly you caould add an extra 600 pounds to your robot with ever touching the ground... Any Ideas?

Shade of 2003.
Teams used suction cups to plant themselves at the top of the ramp. That worked for the first few matches and then after getting ran over by robots for a while the field surface got worn down a bit and the suction cups stopped working.
I suspect the same would happen this year as well.

[Dracco1993]

Originally Posted by Koko Ed

Shade of 2003.
Teams used suction cups to plant themselves at the top of the ramp. That worked for the first few matches and then after getting ran over by robots for a while the field surface got worn down a bit and the suction cups stopped working.
I suspect the same would happen this year as well.

I see your point, but that math was done assuming that the suction cups are about 1/2 to 1/4 of an inch off the ground. They would be more like a hover craft in reverse then suction cups.

[Bongle]

A hybrid of propulsion and wheels is almost useless even if it is deemed allowed (which by the "no other traction on the field allowed" part of the rules can't be done anyway).

I don't think it is useless. The maximum force that can be generated with the wheels for a max-weight robot is 26.7N. With some math, you can determine that 5N and 10N fans could be plausibly added to your robot, which would add 18% and 36% to the acceleration of a max-weight robot, respectively. Some of that would be eaten by the airstream hitting the trailer, but I think a fan approach could actually increase performance.

I think there is a reading of the rules where it would be allowed. Traction generally refers to the contact between a wheel and the ground. Fans aren't enhancing your traction with the field (and unless you have a quickly reversible fan, they actually hurt your braking performance), they are applying a force by pushing against the atmosphere. However, there are also readings of the rules where it wouldn't be allowed, and it'll have to wait until QA opens to see if they are allowable.

[Dracco1993]

Last year we were one of a few teams that used a vacume to pick up the ball so we have some experience with them. One of my friends on the team picked up the ball just using his mouth. He sucked on a vacume tube atached to a cake holder lid. With that much of a surface area he could pick up the ball for about 5 seconds.

[johnr]

Does this make any sense? Six wheeled bot. Four corner wheels driving forward and two side centered wheels driving backward as needed. Or, one wheel dead center of bot that would spin oppisite as needed. Then hand the whole thing over to programers. They can make it work.

[vivek16]

Look, all the ideas with fans:

Why not take your 200 pounds of force going downwards, point that to a side, and use it as a means of propulsion? It would certainly be a lot more efficient than using the force to increase the traction (it will still be low traction).

-Vivek

[spiffyspleen]

Would a holonomic drive system work well? I think it would make it easier to drive, but I don't know for sure. Here is a link to a picture of what I am talking about except that we would have to use the required wheels instead of the omnis. The required wheels should work as well though, because they barely have any traction.
http://wiki.chiefdelphi.com/media/0/..._holonomic.jpg

[smartkid]

You would have to use the wheels in the kit as the casters, the wheel would be huge and bulky but it could work. Now you have to know that an omni-drive works on the principle of wheel slippage. It is designed so that wheel casters slip.

[usbcd36]

While this might make sense initially, holonomic actually starts looking very bad after viewing the COFs for the wheels.

10.2.4.1 Wheels
The wheels supplied in the 2009 KOP are very different from previous years’ kit wheels. The
tread material is Celcon M90, and has the following coefficients of friction on white, rippled
fiberglass plastic sheet
Inline, static: 0.06
Inline, dynamic: 0.05
Transverse, static: 0.14
Transverse, dynamic: 0.10

Yes, the transverse COF is very low, but the inline COF is less than half of it! This means a holonomic drive robot (with the COG in the middle) theoretically wouldn't move at all! In practice, it might, but not much.