Direct Drive CIM Through Toughbox
 

The title says most of it. Is it possible to drive a wheel directly through a CIM motor connected to a Toughbox gearbox (probably with the long output shaft so the wheel will fit)?

We want to make a mecanum drive chassis, and thought it might be more responsive or easier to control if the motors were attached directly through the wheels, instead of going through chain (also because chain is a hassle in general).

Re: Direct Drive CIM Through Toughbox
 

It's definitely possible. Teams have direct driven off the Toughbox all the time. I'd recommend a Nano for a mecanum drive, since you'll only need one motor per wheel.

Re: Direct Drive CIM Through Toughbox
 

Here is the drive base we used in 2011

http://www.frc-designs.com/drives.html#frc525

Re: Direct Drive CIM Through Toughbox
 

Yep. Our standard design was to drive at least 2 of the wheels directly from Super Shifters/CIM motors. Driving from Toughboxes would be only marginally different due to the different physical locations of the shafts.

Re: Direct Drive CIM Through Toughbox
 

Here's what we did in 2011. It was our best competition drivetrain ever. We had it mechanically assembled in one evening.
If we do this again, we'll probably do hex axle instead of keyed.

Re: Direct Drive CIM Through Toughbox
 

That's a clever setup. We are looking at using the Nanotubes for a Mecanum setup this year since we've done Mecanum the past few years but have had weight issues with it due to being a custom setup with the kit toughboxes. Last year our frame, gearboxes, motors, and wheels brought us in at over 60 pounds!

Was there a reason other than speed to bolt the C frame to the top of the Nanotubes? I've been wondering what the best approach would be to mounting bumpers to them and that would certainly solve the problem.

Re: Direct Drive CIM Through Toughbox
 

Speed of assembly, ease of attaching structures (like bumpers) to the frame. Just like you said.

Re: Direct Drive CIM Through Toughbox
 

In 2010 we had this issue, but I think AndyMark has addressed it since then. If you use the Toughbox Nano's, make sure the final gear stage has no lateral movement on the shaft. Otherwise the output shaft bearing could pop out. It's an easy fix (2 washers), but I do believe AM fixed it already.

This was also from 2010, so double check the wheels before you buy. The 6" Mecanum wheels are sheet steel -- very very strong. Because of that, we got away with assembling 1 hub onto each Mecanum wheel, then putting that onto the output shaft of the Toughbox nano. There was roughly 0.25"-0.375" of gap between the Toughbox Nano bearing and the hub, which we filled in with PVC -- you NEED that gap so the Mecanum wheel roller bolts don't interfere with the gearbox as it spins. We then put a 1/4-20 bolt into the hold at the tip of the shaft, which kept the hub from coming off. The whole setup lasted through 2 competitions and 14 hours of little kids banging it around at the Science & Engineering Festival in Oct 2010 in DC. It went over the 12" bumps of 2010 and survived like a champ.

Toughboxes are -- wait for it -- really Tough! I've been a fan of them ever since that season.

Re: Direct Drive CIM Through Toughbox
 

Mecanums / direct driving Toughbox Nanos / Kit Frame is a light drive that's fast to build. Direct drive is the way to go, especially since it saves a lot of time monkeying around with chains. We used it in 2011 and did well.

I really like the Toughbox Nano. It's light and small, and it rolls very smoothly. Very nice little box.

Re: Direct Drive CIM Through Toughbox
 

We have done direct driven CIMs for mecanum in previous years. It works much better than chains (in our opinion!) and we have used nano tubes instead of tough boxes. They worked well for us!

Re: Direct Drive CIM Through Toughbox
 

So, with all of these gearboxes, the andymark hubs are still necessary, right?

Re: Direct Drive CIM Through Toughbox
 

It is very possible the team I'm on 3260 used mecanums for last year to line up right next the hoops and so far every year we just put a hub on a wheel a key in the output shaft screw the end in with a few large washers and ur ready to go

Re: Direct Drive CIM Through Toughbox
 

We used direct-drive BB p80s on our octocanum drive last year, but have switched to direct-drive AM Toughbox minis for this year.

Make sure to support the ends of the shaft and make sure that your gear box mounts aren't going to bend/warp, and the setup is an absolute beast.

Re: Direct Drive CIM Through Toughbox
 

A hub of some sort is necessary, but the shafts are compatible with more than just Andymark products. We're actually going to use the Toughbox Nanotubes with VexPro hubs and Mecanum wheels this year. I believe we have all the parts now, but we probably won't start building the drivetrain until sometime next week.

Re: Direct Drive CIM Through Toughbox
 

None of the designs shown seem to support the other side of the wheel, so you are putting all the force on one side of the wheel... Would this not destroy the gear boxes or bend the shafts when you have 120 pounds on it? Is there some way I'm not seeing where their outer sides are supported, similar to the way the kitbot wheels are set up?

Re: Direct Drive CIM Through Toughbox
 

I'm a big fan of robustness in FRC robots, and would not recommend having any drive shaft unsupported on one end as a general principle. You'll note in this picture that the long output shaft is supported at the edge of the robot by a pillow block.