Mechanum Wheels?

[the man]

We are using mechanum wheels this year, for a few reasons. One we love them. Two the provide great maneuverability. Three there big enough to get over the bump. I really like them.

[moogboy]

Originally Posted by the man

We are using mechanum wheels this year, for a few reasons. One we love them. Two the provide great maneuverability. Three there big enough to get over the bump. I really like them.

What size are you using? getting over the bump was something my team thought to be impossible, but our wheels might be a smaller size. do you think you will have any trouble with traction on the bridge?

[bearbot]

Here is FIRST team 2849 ursamajor and thier sucess with meccaums they workk in bump and terrific on the bridge .We used 8in wheel i am a veteran and mentor on the team.Bumps coming sooon
http://www.youtube.com/watch?v=3Hju0...y7UjRNgBKiTb8I

[372 lives on]

Originally Posted by bearbot

Here is FIRST team 2849 ursamajor and thier sucess with meccaums they workk in bump and terrific on the bridge .We used 8in wheel i am a veteran and mentor on the team

Pics or it didn't happen



Mecanum = chucknorris of wheels(does chuck Norris weigh more than120? .

[bearbot]

Originally Posted by 372 lives on

Pics or it didn't happen



Mecanum = chucknorris of wheels(does chuck Norris weigh more than120? .

Sorry forgot to add the video

[SuzyQ.42]

The decision to use mecanum wheels is a strategy-based one... if you plan to play a heavy, pushing defense, mecanum is probably the wrong choice, as the diagonal wheels are not so great at traction. If you plan to play a swift and extremely maneuverable offense, then mecanum may be the choice for you. Mecanum wheels are also larger than many plain plaction wheels, which may assist you when climbing the bump. The size can also push your CG up, depending on where you fasten the wheel centers.

[Chris is me]

Originally Posted by the man

Three there big enough to get over the bump. I really like them.

Have you actually tested this?

[the man]

We are using the 8 inch. The rollers are incredibly grippy on the bridge, I fore see no issues. More testing will likely occur tomorrow. I will post any thing else we find out about them on here tomorrow. Why would they have a problem with the bump?

[EricH]

Originally Posted by the man

We are using the 8 inch. The rollers are incredibly grippy on the bridge, I fore see no issues. More testing will likely occur tomorrow. I will post any thing else we find out about them on here tomorrow. Why would they have a problem with the bump?

8" wheels, 4" bump, your axle hits smack-dab on the top of the bump. That makes it a little bit tricky to get up and over; I'd put a set of skid plates to knock the bump under the axle to help the robot get over the barrier.

[the man]

I dont get it. As long as your not going mock 5, ok ok at fast speed in terms of robotics competitions, the back wheels will continue to push as you some what gently push your self over the bump. But we will test this tomorrow.

[EricH]

Originally Posted by the man

I dont get it. As long as your not going mock 5, ok ok at fast speed in terms of robotics competitions, the back wheels will continue to push as you some what gently push your self over the bump. But we will test this tomorrow.

When you hit the bump with an 8" wheel, that wheel's entire force on the bump is vertical until you get some lift off the ground on that end. So your back wheels have to work twice as hard.

An easy way to deal with this is to put an angle leading down below your axle from the edge of the frame; this allows the front wheels to get some horizontal tractive force in addition to the vertical, which allows them to help the back wheels out a bit. Do that on both sides of all four wheels, and it'll help you out a lot.

[xXD3sEcR8xX]

Originally Posted by the man

I dont get it. As long as your not going mock 5, ok ok at fast speed in terms of robotics competitions, the back wheels will continue to push as you some what gently push your self over the bump. But we will test this tomorrow.

Mach 5... just saying

I'm not saying no mecanums (or however you spell it), but these are some points made in previous threads:

-Less traction on the key
-As already said, loss in pushing power
-Heavy
-Forces you to use maximum number of motors for drivetrain (not usually an issue)
-While they may not affect your ability to go on the bridge, the ability to stay without being pushed off or falling off of the bridge tips your direction will be tough to deal with
-You won't be driving circles around other's bots unless you have a lot of practice.
-In order to work to their fullest extent, require a lot of thorough engineering
-More complicated to code, even at the minimum level


Like I said, I'm not telling you not to use them, but when you do, be careful and engineer it through (Not meant to sound like most interesting man in the world meme, though I'm tempted. )

[O'Sancheski]

Originally Posted by SuperNerd256

-More complicated to code, even at the minimum level

I disagree with this statement. WPI has a complete library for mecanum wheels. My old team used them last year for the first time and had them programmed on the drivetrain the day we received the shipment from AndyMark.

Originally Posted by O'Sancheski

I disagree with this statement. WPI has a complete library for mecanum wheels. My old team used them last year for the first time and had them programmed on the drivetrain the day we received the shipment from AndyMark.

I mean when you go into the real nitty gritty coding stuff. THe code they give you is fine, but to make it better takes some work.

This is just what I've been told by our programmers, I'm not a master of code myself, however my trustful programmers are.