Direct Drive Four Motor System

[sanddrag]

Originally Posted by Matt Adams

Fighting Words: It comes down to a mater of weight, and I think that if you're smart about your chain size (#25) and sprocket materials (aluminum) you'd be hard pressed to say the weight difference is enough to over come the disadvantages. I don't considering creating a good chain tensioning system upfront and spending a few minutes to tighten it every few matches at the first regional to be terribly inconvenient vs. the tolerances and assembly requirements of building 4 robust gearboxes.

Just some thoughts and fighting words,

Matt

And there you have it. Over the years, I have seen SO MANY chain drives that are WAY oversized (we used to be guilty of this charge as well). There are certainly reasons to use larger chain and/or larger spockets, but try to imagine it being smaller/lighter, and then put forward some effort into making that happen.

This past year on our 6 motor drive robot with the very grippy "McMaster tread" and we used #25 (1/4 pitch) chain and tiny 13 tooth sprockets to link the wheels. Only broke one chain (of four on the machine) once ever and that was due to a very rare circumstance. If we can do #25 with six motors, you can definitely do it with four.

All we had to do was develop a good way to get and keep the sprockets inline, and develop a good tensioning system and we were virtually trouble free from then on out.

There is no good reason to link together your wheels with huge and heavy sprockets. We had the most powerful drive setup you can have, and we had pretty much the most grippy tread you can have and we had the smallest sprockets of anyone, and it worked! And it is no stroke of luck. Small chain, and small sprockets, CAN work for you too.

For all of you stuck in the world of #35, please, step into the future. A future full of wonderful weight savings.

If you aren't using #25 chain in your drive system, either it is an 8 motor drive system, or has 16" wheels, or you are doing something wrong. At least just try it and I think you'll be surprised. #25 chain is wonderful.