RCU Forums - Electric Conversion

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Electric Conversion

It's been awhile since I've been on here an hope you could help. My kids are getting into the RC world and i thought I'd dig out my boats this Spring. They're younger and don't like the loud nitro. I have an old Dumas 45" with a KB40 motor. I'd like to convert it to electric and was looking for motor and running gear suggestions. Is there a single motor out there big enough to move this boat, or would i have to go twins? I don't need to break speed records or anything, and don't want to break the bank either, in case they're not interested. They currently have Tmaxxs with 775 motors. Think I could re-purpose those motors?

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What is the KV rating on the T-Maxx motors? After having this same conversation with someone a day or two ago, I can tell you that yes, a single motor will work. The important part is how big of battery pack do you want to use and can you get a speed controller that will handle the amperage drawn by the motor.
In the other conversion, the gentleman wanted to use a motor that had too high of KV rating and a 6S pack that would have cooked his speed controller so knowing what the motors are rated at,as well as the pack size you plan on using is very important

Quote:

Originally Posted by Hydro Junkie (Post 12515647)

From what the google says, not many people have figured out the kva of this motor. But a lot mentioned close to 1100 at 18v.

I'm not going to spend hundreds on battery packs. I currently have two 2s 7.4v 5200mah lipos in each tmaxx. If I could use those, or add onto those, that would be great. obviously weight is an issue...

But really, if someone has a good recommendation of components, much appreciated. keep in mind, it for kids, so speed isn't a big factor, but obviously it needs to get up on plane and be fun

You can probably get by with 6S although 8S would be better. A long 40mm motor with a Kv between 1000 and 1300 would work on 6S, but a bigger 700-800 motor on 8S would work better. (The original T-Maxx motor had a Kv higher than 1100, closer to 1600. Too high for this big boat.)

Running four 2S packs in series gives 8S, you’ll need an ESC to handle that voltage. A Swordfish 200 HV ESC will work. With just 5200 mAh your run time will be limited, depending on the prop and how the boat is driven expect between 3 and 6 minutes, maybe more if speed is not a goal.

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