Power Problem (seeking help)

[kbt]

Hello everyone in the forum!

I am a beginner here, and I would like to ask for your help. I built a „Los Angeles” submarine in 1:96 scale. But unfortunately I have a problem with the start. If I try to start with every speed, or with full speed, the propulsion rotates the submarine’s lateral rotation. I would need some advice about what to change.
I am using:

Motor: Permax 480 7.2v

Ratio: 1: 2 8

Propeller diameter: 6cm

Thanks for your help.
Béla Király

[Guest]

Re: Power Problem (seeking help)

That's torque roll.

Three things you can do- you can try any one of them or a combination of all three-

1. Decrease the RPM of the motor, gear it down more. A 480 (17000RPM) at 2.8:1 ratio sounds too high revving for a 60mm prop. 4:1 would be better and should also improve your running times.
2. Lower the pitch of the prop by twisting the blades to a shallower angle of attack.
3. Improve the static stability of the boat by putting more lead in the keel, and buoyancy with foam mounted as high as you can get it in the hull but still below the waterline.

You could also try running a smaller prop, although that will not look scale.

I would try options one and three first, and look towards modifying the prop as a last resort.