pic: Sorta WCD

[EricH]

Originally Posted by SuperNerd256

Why are you using the motors apart, with 4 separate gearboxes?

Function of a DeWalt 3-speed--you can really only fit one motor to a gearbox without adding another gearbox on top of it to join the motors. Why would you need the extra speed? Let's see--extra push, easier transition to high gear, and LUDICROUS SPEED!

It wouldn't hurt to add a chain run to make sure that each side gets both motors powering all the wheels together. I realize that those aren't shown, but it may be worth having if weight (and the field) allow.

[Hawiian Cadder]

I am currious as to what ratios are in those dewalts. If i remember correctly it is something like 1-12, 1-16, 1-42. what ratio are you thinking of using for the chain, and what fps does it go?

[Chris is me]

Originally Posted by Hawiian Cadder

I am currious as to what ratios are in those dewalts. If i remember correctly it is something like 1-12, 1-16, 1-42. what ratio are you thinking of using for the chain, and what fps does it go?

I believe with CIMs most people remove a stage to make the transmissions run at 1:3 1:4 1:12.

[Hawiian Cadder]

Originally Posted by Chris is me

I believe with CIMs most people remove a stage to make the transmissions run at 1:3 1:4 1:12.

Ahh, that is correct, My experience is with a dewalt and fisher-price pairing.

This also makes a lot of sense because the first stage is held together largely by the plastic casing, while the deeper in stages are much more secure.

[Frenchie461]

Just to clarify the ratios on the dewalts with the first stage removed are 12:1, 4:1, and 3:1. These are further reduced by a 22:32 sprocket reduction giving speeds of 5, 13, and 17fps (Thank you JVN for your design calculator). The chain is run past 2 idlers to put the sprocket on the drive motor in the right place to only use 1 chain rather than one for each wheel.

[PAR_WIG1350]

Originally Posted by Frenchie461

The chain is run past 2 idlers to put the sprocket on the drive motor in the right place to only use 1 chain rather than one for each wheel.

Wait, one chain per side or one chain per motor and the 2 closest wheels? While the latter sounds fine, I would not advise the former due to the fact that a single failure would render the robot un-steerable. If two chains are used per side, on the other hand, there is at least some degree of redundancy.

[Frenchie461]

Originally Posted by PAR_WIG1350

Wait, one chain per side or one chain per motor and the 2 closest wheels? While the latter sounds fine, I would not advise the former due to the fact that a single failure would render the robot un-steerable. If two chains are used per side, on the other hand, there is at least some degree of redundancy.

1 chain per dewalt, which makes it 2 per side

[Frenchie461]

Originally Posted by EricH

It wouldn't hurt to add a chain run to make sure that each side gets both motors powering all the wheels together. I realize that those aren't shown, but it may be worth having if weight (and the field) allow.

I'll try that, but that doesn't work quite as well with performance wheels, so I'll probably change those to plactions in the center 2.