Nitro guys - how does a 2 speed transmission work?

[dure16]

I'll be converting an old nitro to brushless and am curious about the 2 speed transmission. I've never touched one before.

How do they work? I'm curious how the system switches from one spur gear to the other (or does the engine itself make the change?). Any good tutorials out there?

 

[Camaroboy383]

Centrifugal force chooses the gear.. there are clutches in the center of the spurs.. rpm negates which gear is chosen.. if you can modify a pinion clutch bell gear set to be mounted to your motor shaft you can retain the use of the multi speed transmission..

 

[dure16]

Centrifugal force chooses the gear.. there are clutches in the center of the spurs.. rpm negates which gear is chosen.. if you can modify a pinion clutch bell gear set to be mounted to your motor shaft you can retain the use of the multi speed transmission..

Thank you. I think it would be fun to retain the 2 speed functionality.

I’ve never seen a clutch bell gear. Is it hard to modify for a motor shaft?

Alternatively, would it work as a 1 speed if I simply aligned a brushless motor pinion to one of the spur gears?

 

[gotnitro]

I've swapped nitro engines for bigger nitro engines in plenty of 2 speed transmissions. Some of them made too much power and I was going through parts. BL motors make tons more power than nitro, be careful, you might break something.

 

[Camaroboy383]

Yes you can choose a single gear with a single pinion, obviously you would want to pick the 2nd gear spur..

there are many ways to retain the 2 speed.. one I've seen is modifying standard electric motor pinions.. machining the shoulder off the pinions and drilling down through the center of the tooth path for the grubs.. just have to be sure to ease the hole edges so that any burrs are removed, otherwise it will chew through the spurs..

Other method I've seen is a slug machined from aluminum and pressed into the clutch bell, then drilled and tapped through for grub screws.. those same grub screw holes were filled with button head screws so as to key the clutch bell to the pressed in slug just in case...

 

[KnowAir]

I've thought about converting a T-maxx I've had for years..seems most "lockout" the 2 speed transmission. I started reading up on how to convert, but lost interest. It was poo as a nitro, I can'timagine it'd be any better with more power,LOL. Good luck!!

 

[SrC]

Nitro's take better advanatge of a 2 speed setup. Because of the power band associated with Nitro engines.
With electrics and BLX motors, you simply don't need a 2 speed setup. It's doable. But I feel there is no real advantage to it. Electric motors have a smooth linear power delivery. Nitro/ combustion engines don't.
One reason you never see a scale EV car with a geared transmission. A transmission adds needless weight as well. EV's are way heavier than ICE equivalent size model vehicles. . The EV Batteries weigh a ton.
Not to go off topic. Just an analogy.

 

[@9G]

This video might be a little off topic but I found this awhile back. This guy created a hybrid brushless/nitro in 2 speed configuration.

Here's another video with him actually running the car...

 

[SrC]

That's a hybrid work of art there. Quite complex.

 

[Bustedaw11]

Nitro's take better advanatge of a 2 speed setup. Because of the power band associated with Nitro engines.
With electrics and BLX motors, you simply don't need a 2 speed setup. It's doable. But I feel there is no real advantage to it. Electric motors have a smooth linear power delivery. Nitro/ combustion engines don't.
One reason you never see a scale EV car with a geared transmission. A transmission adds needless weight as well. EV's are way heavier than ICE equivalent size model vehicles. . The EV Batteries weigh a ton.
Not to go off topic. Just an analogy.

This is good info right here. There is really no point in going out of the way to keep a 2 speed with a brushless setup.

Nitro motors have a small rpm window where they produce good power- thus the 2 speed to keep them in that power band..
Thats not needed on a brushless motor.

 

[gotnitro]

This video might be a little off topic but I found this awhile back. This guy created a hybrid brushless/nitro in 2 speed configuration.

Here's another video with him actually running the car...

Lol, man that guy was running super lean. Not supposed to sound like a chain saw after letting off throttle.

 

[DLK83]

I'll be converting an old nitro to brushless and am curious about the 2 speed transmission. I've never touched one before.

How do they work? I'm curious how the system switches from one spur gear to the other (or does the engine itself make the change?). Any good tutorials out there?

"Thats like asking how a rainbow works, or posa' traction rear end on a Plymouth works, it just does"....