Pushing Power?
 

I was wondering how well we'll do in pushing matches (estimates of course, we won't find out till we get to shovin)... we have 4 CIM motors powering 8 inch plaction wheelson a 16:1 gearbox... think we can do some pushing around or will we be knocked about like a sailboat in a hurricane?:confused:

Re: Pushing Power?
 

Oh wow, you shouldn't have to worry about being pushed around. You have definately enough pushing power as you guys have a very nice gear ratio. Most teams are going to go with the andymark toughboxes or supershifters, which have 12.75:1 gear ratio unless another option is used.

Gl on the last week of robotics!

Re: Pushing Power?
 

Not to hijack this thread, but how good do you think WE will do?
We have 2 andymark gearboxes driving a set of tank treads, each driven by 2 CIMS.

Re: Pushing Power?
 

You could calculate your pushing power with JVN's design calculator.
http://www.chiefdelphi.com/media/papers/2059

Re: Pushing Power?
 

Pushing power will be about average. Its going to be pretty hard to push YOU though.

I honestly don't see a reason why teams would worry too much about pushing and being pushed. The best defense will be getting in the way of the other team and not ramming them in my opinion.

Re: Pushing Power?
 

Everyone using 4 CIMs in their drive has equal amounts of pushing POWER (assuming similar inefficiencies in their drive)...the better question is what sort of linear pushing FORCE will your robot be able to exert?

Luckily, this is an easy question to answer. Head down to Walmart (go ahead, I'll wait) and purchase a linear force scale, or a bathroom scale in a pinch. Put your robot on carpet (fully weighted with all bumpers to maximize robot normal force, of course) and let her rip against the scale!

Record your results... Check against theoretical.

Voila!

-John

PS - An alternate, significantly less quantitative, but seemingly preferred method involves using your robot to push some fat kid across linoleum floor on his butt. Personally, I like the fish scale. Your mileage may vary.

Re: Pushing Power?
 

what better way to get in their way then to push them against a wall long enough for someone to steal their ball?

Re: Pushing Power?
 

Block their shot.
Hit them as they line up to take the shot.
Block them as they come out of the tunnel.
Get the ball before they do.
Keep them from entering the zone with the balls.
I'm sure some other folks around here can think of more.

Also remember: Drive power != pushing power. If your wheels slip, then you're not going to get any more power out of that drivetrain, no matter how many or what type of motors you have aboard.

Re: Pushing Power?
 

I bet pushing power is gonna be more important than people think. It might even be worse than 07 since there are so few playing pieces.

Re: Pushing Power?
 

my take on it is yeah a mechnam bot is more agile than our tank drive bot with plaction wheels but we can push them anywhere we want to... if they can't get to a ball because we're pushing them all over the floor... how can they score? also, eric, most of your strategies require pushing... block them out of the tunnel... pushing, hit them as they shoot, pushing, any bump strategy you can name... most likely pushing... pushing isn't key, but i wouldn't dismiss it as quickly as some seem to have... we shall see in week one regionals i guess when we see the first mechnam v. traction/plaction wheel matchups

Re: Pushing Power?
 

Though of course the other thing I forgot to mention is, you don't want to abuse your pushing power until the finals otherwise your great defense will hurt your ranking.

I bet teams will begin showing off their best defensive skills saturday morning right before alliance selection.

Re: Pushing Power?
 

I never said they required or didn't require pushing. However, rookies like yourself have much to learn about FRC-style defense. Hitting another robot (not pushing, hitting--there is a difference) can easily throw them off enough to mess up a shot. Blocking someone out of a tunnel can merely be parking broadside to the tunnel. Let them get a penalty pushing you through, in necessary.

Any time there is robot-to-robot contact, somebody's alignment can get messed up. Any time alignment gets messed up, it takes time to correct, and by the time the correction is made, it is often too late.

Incidentally, should you push said mecanum robot against a wall or other field element, you should start counting if they can't move. The refs will as well. If you should prevent them from moving for more than 5 seconds, and not back away by the required amount, you get a penalty under <G29>. That's as good as them playing defense on your alliance, because even if you did score that ball that you took from them, you get no gain from it.

Re: Pushing Power?
 

we are going for a fast mecanum robot, with 1 to 12 gearboxes, we hope to drive circles around people instead of pushing them

Re: Pushing Power?
 

Maybe. But if they average 5 goals a match, while you get 2, it would be a good idea to play defense on them the entire match and try to hold them to under 3 goals. I think if they are a mecanum drive, it shouldn't be that hard to hold a team to under 3 goals. It is all about figuring out what gives your alliance the best chance at winning.

Several people have mentioned that the 'pushing' bots will need to catch the mecanum/manuverable bots. The problem with this is the defensive bot knows (or atleast should) where the offensive robot is going, diminishing a lot of the manuverable bot's advantage. Just meet the robot at the ball, where it is going to line up to score, by the tunnel or on the way to the tower and push it out of the way.

Re: Pushing Power?
 

Just remember that your logic would mean that you would still lose by 3 goals either way. When you are playing defense the entire match you aren't scoring your 2 goals...

Also remember that if you lose you get the winning team's score...so holding a team's score down during the qualification rounds really does nothing unless you can beat their alliance.

Example
You play a regular match... You lose 14 to 10

You play the same match and you lose 6 to 2

The losing and winning alliances will get 14 points in the first example..and the winning team will get an additional 20 points of coopertition points. The winners get 34 points and the losers get 14..

In the second match both teams get 6 points....and the winners get a 4 point bonus... netting 10 for the winners...and 6 for the losers.

Which match would you rather lose?

I think that in the qualification rounds that teams should concentrate on scoring ... defense does not net you points... Seeding is about the points.

Defensive struggles will net neither team very many points...

This is an offensive game during qualifications... concentrate on scoring...maybe play a little defense at the very end... if its close..

To be honest... one strategy that you might consider in a match where you are overmatched by the other alliance is to not score at all and help them score as much as you can.... The net in that match is the same for both teams....winners score...

During eliminations defense will play a greater role and scores will go down accordingly...

In qualifications a team should be busy helping their alliance score goals in whatever way they can...
Playing strong defense only hurts your chances of seeding by bringing the seeding points down... for everyone...

As I said... the only time defense might be played is if the game is tight...and near the end...

my 2 cents at least.

good luck and we will see you at the competition...!!!