The Barrier Thread

[Ninja_Bait]

Originally Posted by ttldomination

Who said that a WCD has to have 4" wheels?

- Sunny G.

This coming from an East Coaster, of course.

[krazyman1013]

Go on the bump at an angle with 6" wheels and you can clear the bump without damage.

[Ninja_Bait]

Can you clarify and demonstrate that, please?

[dez250]

I'm putting it out there and betting the majority of teams who weren't around for 2004 who try to climb over the barrier will end up like below.



You need to plan for worst case scenario, other robots contacting you and obstacles in your way as you try to traverse the barrier, if you choose to go that way. Trying to cross the barrier in your lab in a best case scenario would be as effective to your team as practicing your robot shooting at the hoops using a football.

Oh and for those of you who think you will not have damage to your robot if you just try to plow over the barrier at high speed, I suggest you do a real world simulation of this. Go find yourself some road hazard strips like this (or a simple curb) and feel the result of going over those even at 10 MPH. I think you will be surprised at the second thoughts you might have at just plowing into the barrier then.

[sanddrag]

Originally Posted by dez250

Oh and for those of you who think you will not have damage to your robot if you just try to plow over the barrier at high speed, I suggest you do a real world simulation of this. Go find yourself some road hazard strips like this (or a simple curb) and feel the result of going over those even at 10 MPH. I think you will be surprised at the second thoughts you might have at just plowing into the barrier then.

Well, automobiles have a suspension typically, and honestly driving fast over most normal speed bumps works just fine. I'm not so sure I'd do it with a curb, at least not in my own car.

[pfreivald]

Originally Posted by sanddrag

Well, automobiles have a suspension typically, and honestly driving fast over most normal speed bumps works just fine. I'm not so sure I'd do it with a curb, at least not in my own car.

I think he means to drive over them with an FRC robot(?).

[dez250]

Originally Posted by pfreivald

I think he means to drive over them with an FRC robot(?).

No I meant in a car, because a car is designed to absorb and disperse the shock of bumps and you will still feel it. Now imagine the shock with no suspension or dampening and having very little clearance.

[Yes i know there are many other differences to take into perspective also, like weight, but this is just to get brains thinking more toward reality.]

[pfreivald]

Originally Posted by dez250

No I meant in a car

Very good, then... I liken to ramming the 4" barrier with a 6" wheel to ramming a 20" curb with your 30" car tire.

[JamesBrown]

Originally Posted by dez250

Oh and for those of you who think you will not have damage to your robot if you just try to plow over the barrier at high speed, I suggest you do a real world simulation of this. Go find yourself some road hazard strips like this (or a simple curb) and feel the result of going over those even at 10 MPH. I think you will be surprised at the second thoughts you might have at just plowing into the barrier then.

This is a terrible analogy, there is no connection between hitting a speed bump at 10 mph in a 4wd vehicle with suspension designed to drive on a mostly flat surface and hitting a 4 inch bar with a 120lbs robot that is being designed to do exactly that.

Originally Posted by pfreivald

Very good, then... I liken to ramming the 4" barrier with a 6" wheel to ramming a 20" curb with your 30" car tire.

This just makes the analogy worse a standard car would clearly never climb a 20" barrier, that isnt what it is designed to do. A 6 or 8 wheel tank steer robot can easily climb over the 4" bar if the driver is smart about it and it the system is designed to do this. There will be a significant number of very good teams who stick with 6 or 8 wheel drive using 6 inch wheels. There will be less people tipping over due to going over the barrier than there were who tipped going up ramps in 2006 or 2010 or up the stairs in 2004. I would even guess that more robots will tip this season trying to go over the bridge than trying to climb the barrier.

[pfreivald]

Originally Posted by JamesBrown

A 6 or 8 wheel tank steer robot can easily climb over the 4" bar if the driver is smart about it and it the system is designed to do this.

Sure, but I can see a relationship between speed and damage/wear here that's rather obvious if the system is not well designed.

[HammadB]

What are teams thinking to get over the bump, I am really confused as to how 6 inch wheels 8WD can do it w/out some sort of skid plate in the front to get off the ground, but then your climb becomes....ugly

[mdiradoorian]

Originally Posted by NuclearNK

What are teams thinking to get over the bump, I am really confused as to how 6 inch wheels 8WD can do it w/out some sort of skid plate in the front to get off the ground, but then your climb becomes....ugly

They are thinking about another way to get to the other side of the field whenever the bridge is being used or a robot died or something in that order. In my opinion it is a better choice to go over but every team has their own strength, weaknesses, and opinion for the features on the robot.