Planetary Gearbox Possibility?

[ThatIndianKid89]

Question.

Is it possible to hook up a 3" CIM to the planetary gearboxes included in the kit? I know it's possible to use the 2.5" CIMs but we're thinking about using the 3" CIMs for more torque/speed.

[sanddrag]

I think your reason there might be a bit flawed. The large CIM motor (one of them) is less powerful than the small CIM motor (one of them). If you put a large CIM into a the planetary, you will get more torque, more weight, less speed, less power, and a larger risk of failure (due to the increased torque).

Can it be done? Yes. Would I recommend it? Probably not.

What is the application?

[ThatIndianKid89]

huh.

thanks for that. lol. That actually helps us out a bit. Do you know off-chance what kind of fps we can get off of the 2.5" hooked up w/ the planetary? (this is all for our drivetrain by the way)

[gburlison]

Originally Posted by ThatIndianKid89

Question.

Is it possible to hook up a 3" CIM to the planetary gearboxes included in the kit? I know it's possible to use the 2.5" CIMs but we're thinking about using the 3" CIMs for more torque/speed.

The 3" CIMs have more torque, but not more speed. In fact the larger CIMs are only have about 80% the power of the smaller CIMs. Bigger is not always better.

That said, anything is possible.

We looked at mating the 3" CIM to the 56mm banebot transmissions, but decided to solve our problems in a different way.

This what we found out.

The shaft diameter and length appears to be correct.
The shaft should be keyed.
We removed the long bolt from last years 3" CIM so that we would have two long bolts to make it easier to mount.
The mounting plate on the transmission would have to be modified to accept the bolts from the CIM.

Keep in mind that we did not actually make make the necessary modifications, so I am not sure other problems might come up.

[Lil' Lavery]

Originally Posted by ThatIndianKid89

huh.

thanks for that. lol. That actually helps us out a bit. Do you know off-chance what kind of fps we can get off of the 2.5" hooked up w/ the planetary? (this is all for our drivetrain by the way)

It depends on if/what reduction you have after the gearbox, and what size wheels/pulleys you are using. But, the Banebots transmission has a 12:1 reduction (can be changed to 16:1 with a kit from Banebots), and the free speed of the 2.5" CIM is 5500 RPM. Under drive-train load, you can probably expect around 4320-4400 RPM. If you don't do any further reductions and are using the 6" Kit of Parts wheels, that would translate to about 9.4 (4320 rpm/60 = 72 rps /12 = 6 rps*6pi=113.094 ips/12=9.425 fps) feet per second (probably a bit lower depending on how inefficient your drive system is).