Mecanum Rolling Chassis

[Akash Rastogi]

Originally Posted by BJC

This-- it really does look classy. Just make sure to get a lot of driver training so you can use it to it's fullest potential come competition.

Best of Luck!
Regards, Bryan

Ditto! Looks like you guys put in a lot of work for this.

How well are the Modulox gearboxes working out for you? The integration is pretty neat!

Again, great start to what I'm sure will be a solid robot. Keep us posted!

[Ryan Dognaux]

Looks great, I can't wait to see what you put on top of it.

Mecanum Haters Gonna Hate™

[lcoreyl]

Originally Posted by Wing

What you gain with a third axis you lose in traction and power. Since the omnidirectional motion of meccanums is produced by vector summation, you'll always have some sort of power loss in whatever direction you go in. Combine that with the low coefficient of friction, your robot may be able to go sideways, but you won't be going fast, and your drivetrain will not have much power, which is never an ideal combination. A 6 wheel skid drive is proven to be far superior in every category, especially since the traction makes up for the lack of sideways movement.

Just posted a whitepaper addressing my disagreement with much of this. The link is in my signature.

But, let's not turn this into a meccanum bashing thread again, shall we?

+1 irony

The main important reason for your choice was because you thought it would be cool and would be a neat learning experience, and that's all that really should matter when it comes down to it. I also like the paint job on this drivetrain, it definitely looks neat!

This part I can fully agree with you on!

The Modulox has worked out very well. everything is Aluminum except the bearings and output shaft. We have discovered that chassis construction is very important to the success of the Mecanum drive. Both frames we have built were very rigid, square and durable. All of our cut dimensions are +- .010 and all of our bends are +-.030. All rivet locations were pre drilled and require very little modification for assembly. There are 125 3/16 blind rivets holding 9 parts together. With the CIMS the chassis weighs in at 43 lbs.

[PVCpirate]

For the pushing match argument against mecanums, how often are you in a straight pushing match during a match? The situation most people describe in making this argument is a six wheel tank drive bot pushing a helpless mecanum drive bot halfway across the field. Any mecanum bot that I've helped build might be pushed some, but with the right driver it would spin away from the pusher and be back down the field in no time.

[Billfred]

Originally Posted by PVCpirate

For the pushing match argument against mecanums, how often are you in a straight pushing match during a match? The situation most people describe in making this argument is a six wheel tank drive bot pushing a helpless mecanum drive bot halfway across the field. Any mecanum bot that I've helped build might be pushed some, but with the right driver it would spin away from the pusher and be back down the field in no time.

Not often, but when it counts... (Really, the relative inefficiency inherent to mecanums is what ruled it out for me this year; we favored straight-line speed without using so many of the high-powered motors.)

But frankly, you could put square wheels on this thing and it'd still look boss. I look forward to seeing the whole thing!

[Anupam Goli]

Originally Posted by DMike

It's Cool.

What other reason do you need? As long as you didn't choose it because you think it gives some competitive advantage, it's fine in my books.

Maybe this team isn't looking at becoming 1114 just yet, and they just want to have fun building a robot and learn something. It's not always about the competition with every team.

[ehfeinberg]

Did you make those wheels? They don't look like either Andymark or Vexpro Mecanum wheels.

Love the paint scheme The white rollers are a nice touch.

[dcarr]

Beautiful. Love the color scheme. Hope mecanum works out for you.

The positive aspects of mecanum are surely well known as well the negatives. Cool is quite often used for design inspiration. Harley Earl would certainly agree as well as many other great designers. The cool in the design attracts attention and gives us the opportunity to explain the building process and FIRST. It's a solid design, form-function-finish.

[EricH]

Originally Posted by DMike

The cool in the design attracts attention and gives us the opportunity to explain the building process and FIRST. It's a solid design, form-function-finish.

This is more what I was looking for, along with the later post. Just saying "it's cool" is like will.i.am saying the 2011 game was "dope" at Kickoff--there are a number of possible meanings. (For example, someone just saw mecanums and said "Oooh, I want some!" is one potential meaning.)

A little more content like this, however--the attention attractor for non-FIRSTers, the testing done so far, and other similar things--and the meaning is clear: you've looked at the alternatives and decided this is the one.

Out of curiosity... is a matching shooter going on top? You've got 4 weeks to perfect that, and a driving base to work with. Or is there something else up your sleeves?

[cadandcookies]

I wish our chassis looked that good! Serious props, especially for a second year team. I think the subject of mecanum drive has been beaten to death, so I'm just going to sit back and admire that beautiful frame!