pic: DeWalt drive base

[newton418]

Slick design, I'd love to see pictures of the real version, and perhaps some battle reports, so make sure to keep us updated after next season.

Originally Posted by Hachiban VIII

Correct me if I'm wrong, but isn't it risky to use two shifters on the same side?

Suppose one of the servos stops shifting... Then you'll have two gearboxes chained together running at different speeds. The DeWalts will strip themselves, and you'll lose half your drive train.

Yes, it is an unlikely scenario. But its the kind of disaster that could ruin your day.

418 has worked with a similar design for the last 3 years, and the only time we've had a shifting problem is when the backup battery wasn't charged... so none of the DeWalts shifted.

IF one of them didn't shift, then the DeWalt that didn't shift would just be powered by the one that did, so it shouldn't create any significant damage (though it will be quite obvious something is wrong). If this happened, I'm sure the driver would just shift back and stick with that gear for the rest of the match. But again, this is a very unlikely scenario if you follow the whitepaper word for word and your code does what you want it to.

Originally Posted by richardmcc2

It wouldn't be quite as risky if you didn't chain all 6 wheels together...just connecting the middle wheels to the back wheels...I would probably try that first and see how it drives before added a second set of chains. On the other hand, I have seen other teams like 418 use this configuration successfully with no shifting problems

We did this our first year with the DeWalts, and learned a valuable lesson.
If you have one DeWalt powering 2 wheels, and another powering 1 wheel, you will have a significant power bias. Think of it this way, you get into a pushing match, your back wheels have their own CIM-DeWalt to themselves, and the middle and front wheels share another. While the back DeWalt easily delivers enough torque to slip your back wheels (creating significant wear on the thread, and reducing your traction) your other DeWalt struggles to provide enough torque to the the middle and front wheels. I'm sure you COULD distribute the weight such that the traction of the back wheels is the same as the combine traction of the middle and front wheels, but that seems unnecessarily constraining.

Another advantage is that if one of your back wheels isn't contacting the ground, the wheels that are contacting the ground still have the power of both CIM-DeWalt assemblies. This might seem like an unlikely scenario, but if you lower your center wheels (as most teams with 6 wheel drive do), and your center of mass changes (you pick up a heavy game piece, for instance) then before you realize it you're driving around on your center and front wheels... and half your power is uselessly spinning wheels that aren't contacting anything.