Does this chassis look as if it would work?

[MSOSDev]

Could you explain what you mean by firing off the side? Do you mean against the castle walls or the guardrails? I feel like the majority of teams are going to insure their robot can adequately cross many, if not all of the obstacles. If we can be quick in shooting the ball and running back under the low bar to grab another one, and if we shoot extremely accurately. I see a very effective alliance and team strategy that could be put in place. As they damage defenses they feed balls into the courtyard, we can have them picked up and fired within 5-8 seconds.

[otherguy]

Could you explain what you mean by firing off the side?

I took it as meaning have your shooter face the left or right side of your drive train. That way there's no reason to need to strafe into the corner, just drive straight in up against the side of the field until you hit the wall the driver stations are on. That gets you into the corner with no fancy drive train, and a pretty simple manuver for your drivers.

[philso]

Originally Posted by JesseK

Mecanum - the biggest issue will be making sure the tabs don't get bent while crossing any of the platforms. It may be a good year to spend some weight on the Mecanum HD's from AM if you find the aluminum tabs bend or fatigue.

Originally Posted by Aur0r4

We used big mecanum wheels during Breakaway...they did surprisingly well on those ramps. I think bigger ones could probably *manage* to get over most of the defenses.

However, we found out that even the impact of coming down off the Breakaway ramps eventually started bending the heck out of the roller support tabs, eventually jamming them. Later in the competition season a major pit task was fixing all the bent tabs....and at like 400 bucks for a set, we weren't in the position to have spares.

I think mecanums would eventually get wrecked in this game.

With the "rough terrain" and all the ramps, you are likely to bend the roller support tabs as Aur0r4 found. The team we were with in 2012 used the AM 8" Mecanums. If our robot ever touched the edge of one of the bridges when it was not straight on, even at low speed, it would bend some of those tabs. A jammed roller would cause the robot to drive erratically (normal and strafe). We got used to jacking the robot up between each and every match and having a crew of 4 people, each checking one wheel to make sure none of the rollers was jammed. If one was jammed, the bolt holding it on would have to be removed so that the tab could be twisted back "just right" using a pair of channel-lock pliers. This was not fun at all for the pit crew nor was it fun for the driver.

[FRC Warrior]

Originally Posted by MSOSDev

We were looking to shoot from the corner of the opposing teams courtyard, that way you don't line up a shot every time. Just go to the corner, slide in sideways, put the shooter at a prefigured angle, fire, and get out. With normal wheels you'd have to back into the corner while turning. Even then you can't guarantee a snug fit every time.

Maybe use a turret?

[BBray_T1296]

Here is our chassis crossing the 4" bump in 2012 with AndyMark 6" mecanum HD wheels. Worked fine on the real thing with a fully loaded robot.

https://youtu.be/jl8pHpCjQtY

There were deflector plates at 45 degrees on both sides of the wheels that extended to about 2.5" above the ground. Our wheel modules were clam shells that surrounded the wheel, included the bearings, and mounted our toughbox nano gearboxes.

[RaptorRobot1711]

Originally Posted by MSOSDev

We were looking to shoot from the corner of the opposing teams courtyard, that way you don't line up a shot every time. Just go to the corner, slide in sideways, put the shooter at a prefigured angle, fire, and get out. With normal wheels you'd have to back into the corner while turning. Even then you can't guarantee a snug fit every time.

It's no use being able to save time with mecanums if you get over the defenses into the opponents courtyard because you're using macanums

[evanperryg]

Originally Posted by MSOSDev

A few other posts within this forum go into how Mecanum wheels would not be a good drive system type for this year's game. While we are considering pneumatic tires which are very likely to work, we are reluctant to lose the ability to strafe and quickly navigate the field. This is our current plan for our chassis which utilizes Mecanum wheels, and can be switched with the pneumatic tires at any time. This allows us to go to the competition with both sets of wheels and interchange them. The chassis has 6 inches of ground clearance. What is your opinion on the effectiveness of this chassis and drive system?


http://i.imgur.com/pJ9hPDj.png?1

Pneumatic wheels have so much grip that you'd probably couldn't turn with this base. But, with mecanums, you have no viable way of easily getting over the defenses without a separate mecanism. If you want to be able to use pneumatic wheels as a backup, you'll probably need a 6-wheel center drop.

[IronicDeadBird]

Originally Posted by MSOSDev

A few other posts within this forum go into how Mecanum wheels would not be a good drive system type for this year's game. While we are considering pneumatic tires which are very likely to work, we are reluctant to lose the ability to strafe and quickly navigate the field. This is our current plan for our chassis which utilizes Mecanum wheels, and can be switched with the pneumatic tires at any time. This allows us to go to the competition with both sets of wheels and interchange them. The chassis has 6 inches of ground clearance. What is your opinion on the effectiveness of this chassis and drive system?


http://i.imgur.com/pJ9hPDj.png?1

I'm no expert at modular systems but yeah that looks like it will work. Just keep in mind extrusions shouldn't go down on that design they should be up to keep the clearance. I'm interested in knowing why you would want the interchangeability.
I'm personally hoping the reason why you want the interchangeability is some dope strategy...

[Aur0r4]

We used big mecanum wheels during Breakaway...they did surprisingly well on those ramps. I think bigger ones could probably *manage* to get over most of the defenses.

However, we found out that even the impact of coming down off the Breakaway ramps eventually started bending the heck out of the roller support tabs, eventually jamming them. Later in the competition season a major pit task was fixing all the bent tabs....and at like 400 bucks for a set, we weren't in the position to have spares.

I think mecanums would eventually get wrecked in this game.

[evanperryg]

Originally Posted by Aur0r4

We used big mecanum wheels during Breakaway...they did surprisingly well on those ramps. I think bigger ones could probably *manage* to get over most of the defenses.
However, we found out that even the impact of coming down off the Breakaway ramps eventually started bending the heck out of the roller support tabs, eventually jamming them. Later in the competition season a major pit task was fixing all the bent tabs....and at like 400 bucks for a set, we weren't in the position to have spares.
I think mecanums would eventually get wrecked in this game.

We used mecanums in 2010 as well. Only year we've ever done it. I wasn't on the team at the time, but we still have the chassis from our 2010 bot with wheels still attached, and they seem fine. This could have just been constant fixing, or we just got lucky. Either way, mecs offer little that another drivetrain can't offer you in this game, at the expense of being more likely to struggle with the defenses. A decent driver should be able to maneuver this field easily on a tank drive.