Mecanum Wheels

[hrench]

Originally Posted by Max Boord

Built your chassis slightly floppy. This allows all the wheels to touch the ground on imperfect terrain (like carpet.)

the times we've built mechanum, we've discovered its been really important for all four wheels to be on the ground. If your 'after school project' has the ability to have independent suspension, I recommend it. We built a robot with simple gas struts on the four corners and it kept the wheels on the floor. Even with a flat floor, when you corner, stop, etc, you can lift wheels and lose control.

As for which gearbox, even when we've done Andymark wheels it made sense to use Banebot planetary gear boxes. Since you need a motor on each wheel anyway, these work great and make a nice installation. Unless you need more power, like two CIMS on each wheel. http://banebots.com/c/P80K-S4 just something different to consider.


And as for motors, everyone here is used to FRC rules, so we don't suggest alot of motors that aren't FRC legal, but there are many motors out there. The CIM at a mere 337 watts isn't close to the most powerful available. It's just what we know. Most scooters are in the 500w range and hub motors go alot higher. Depends on what you need power-wise. CIMS are a great value, but don't be afraid to look around.

[Kyle Kurth]

Originally Posted by Lil' Lavery

How smooth is the asphalt it will be drivng on?

The asphalt is like the PIT area of a nascar track.

[hrench]

Originally Posted by hrench

CIMS are a great value, but don't be afraid to look around.

Just a little 'looking around' flushed out this motor--peak 3.8 HP works out to 2800watts. wow.

http://www.robotmarketplace.com/products/0-A40-300.html


But price of $330 is pretty high too.

[asid61]

Originally Posted by hrench

Just a little 'looking around' flushed out this motor--peak 3.8 HP works out to 2800watts. wow.

http://www.robotmarketplace.com/products/0-A40-300.html


But price of $330 is pretty high too.

SSS 5694:
http://www.horracing.com/product_inf...roducts_id=609

If you use 3-4 lead acid batteries in series, they should produce enough voltage for it to really pump out the power. They need a brushless speed controller to go with them, but they're pretty good value.

[Scott Kozutsky]

Given that the bot is driving on asphalt, I wouldn't trust any of the frc intended mecanum wheels to last any reasonable amount of time. Couple that with the fact that the asphalt likely isn't perfectly flat and you've got a complicated, expensive, heavy, high maintenance and badly performing platform as compared to tankdrive or front wheel steering like what's on the jeep originally.

Even on carpet I wouldn't really trust mecanum wheels with more than 700w per wheel, they just aren't intended to either go that fast or use that much force (depending on how you're geared).

Also what manufacturing resources do you have? this is still a really important question.

If you really want to strafe, swerve or crab drive is probably the easiest/best way to do it well. 1640 has good code resources and you can buy good KOTS swerve drives and a chassis to mount it to.

[Morgan B]

[quote=Scott Kozutsky;1399804] Also what manufacturing resources do you have? /QUOTE]

We have a pretty advanced shop to work in. So a lot is possible. There are only 2 of us working on it, which in turn doesn't give us much flexibility on what we can custom manufacture.