2015: Year of the Mecanum

[TheJoe]

We were warned that "Change is Coming," and it certainly did.
It seems as though with the limited robot-robot interaction, we don't need the large, defensive powerhouse that FRC generally sees.

Could it be possible that mecanum drivetrains are the ideal way to go because of their maneuverability?

[teafreak45]

I would agree with you on the drive. While watching the video, I was thinking that would be the most used and best drive train for this year.

[Kevin Sevcik]

You see those bumps called the scoring platforms? Those are going to going to cause all sorts of headaches for mecanums. 5-wheel strafe drive with the strafe wheel on a pneumatic suspension should work well, I think.

[smart1]

Originally Posted by Kevin Sevcik

You see those bumps called the scoring platforms? Those are going to going to cause all sorts of headaches for mecanums. 5-wheel strafe drive with the strafe wheel on a pneumatic suspension should work well, I think.

I don't think there is a need to climb those, just go around them.

[Jonathan Norris]

Originally Posted by Kevin Sevcik

You see those bumps called the scoring platforms? Those are going to going to cause all sorts of headaches for mecanums. 5-wheel strafe drive with the strafe wheel on a pneumatic suspension should work well, I think.

This. Mecanums won't handle the bumps well, also mecanums need a very even weight distribution to work properly, I imagine there are going to be a lot of unevenly distributed robots this year...

[smart1]

I would try to set the center of gravity of the robot with the game piece, so when you lift it's balanced.

[Ether]

Originally Posted by Kevin Sevcik

You see those bumps called the scoring platforms? Those are going to going to cause all sorts of headaches for mecanums.

Has anyone looked at the field drawings yet? In the game video it looks like the platforms aren't that high, and there are ramps all around. How high is the platform, and what is the grade of the ramps?

[ATannahill]

Originally Posted by Ether

Has anyone looked at the field drawings yet? In the game video it looks like the platforms aren't that high, and there are ramps all around. How high is the platform, and what is the grade of the ramps?

The incline is 16 degrees, the height is two inches. This is from page 8 of the game manual. These values are nominal but the official values are in the field drawing.

[alicen]

Originally Posted by Kevin Sevcik

You see those bumps called the scoring platforms? Those are going to going to cause all sorts of headaches for mecanums. 5-wheel strafe drive with the strafe wheel on a pneumatic suspension should work well, I think.

Whenever we did mecanums, we always had suspension on each wheel so that all wheels were always in contact with the floor. They even went over the humps in Breakaway just fine!

[Jacob Bendicksen]

Originally Posted by Ether

Has anyone looked at the field drawings yet? In the game video it looks like the platforms aren't that high, and there are ramps all around. How high is the platform, and what is the grade of the ramps?

The angle of the ramp is 16 degrees, and the 'hypotenuse' is 7.125 inches. 7.125*sin(16) works out to 1.96 inches.

[Ether]

Originally Posted by Jacob Bendicksen

The angle of the ramp is 16 degrees, and the 'hypotenuse' is 7.125 inches. 7.125*sin(16) works out to 1.96 inches.

My guess is this won't be a major issue with a properly built and driven mecanum.

[Kevin Sevcik]

Originally Posted by Ether

My guess is this won't be a major issue with a properly built and driven mecanum.

For the record, we tried mecanums in 2008 and 2009, and just the plywood under the carpet would make things go wonky if you were trying to do a precise alignment.

I'm not saying they'll be undriveable, I'm just saying they're going to make auto and certain precision tasks a wee bit more challenging and error prone than they need to be.

[Ether]

Originally Posted by Kevin Sevcik

I'm not saying they'll be undriveable, I'm just saying they're going to make auto and certain precision tasks a wee bit more challenging and error prone than they need to be.

My prediction: There will be mecs that struggle mightily and those that dance like olympic figure skaters.

[hexane]

From our team's experience, the only time that mecanums have ever had troubles were on the bridges in 2012. Even then, the problem was the lower coefficient of friction rather than getting up on them, and we were still able to balance 2 robots better than most teams.

[chrisfl]

Originally Posted by hexane

From our team's experience, the only time that mecanums have ever had troubles were on the bridges in 2012. Even then, the problem was the lower coefficient of friction rather than getting up on them, and we were still able to balance 2 robots better than most teams.

It was the same for us. We used mechanum in 2012 and our only problem was staying in one place on the bridge. We had no problem going up and down it while at an angle.