Hi all,
I made few test with 70mm props and high torque motors.
Test was done at 12V.
No load means prop and coupler attached, but prop is above water.
Prop A : Raboesch 4 Blade C Type Dia 70mm / Pitch 62.2mm
Prop B : Raboesch 4 Blade Kort (capped) Dia 70mm / Pitch 71.7mm
Motor 1 : Buehler 1.13.043.242 (40mm Dia 12V motor)
No Load - 0.2A @2250 RPM
Prop A - 1.8A @1290 RPM
Prop B - 2.1A @1080 RPM
Comment : Great for smaller prop, but not for these 70mm props.
Motor 2 : Robbe Power755/40
No Load - 1.2A @5550 RPM
Prop A - 10.4A @1980 RPM
Prop B - 11.0A @1680 RPM
Comment : Motor got too hot to touch. Burnt smell after 1min.
Do not recommend for 70mm brass prop !
This motor is not designed to run at 10A.
Motor 3 : Caldercraft 900 from MBB
No Load - 0.6A @2850 RPM
Prop A - 3.8A @1560 RPM
Prop B - 4.6A @1350 RPM
Comment : Great motor at great price. I prefer more thrust, but maybe OK for scale speed.
Motor 4 : Mobile Marine Models T-12
No Load - 1.3A @4800 RPM
Prop A - 8.6A @1860 RPM
Prop B - 9.3A @1500 RPM
Comment : Very powerful, but motor got very hot. Current draw is bit too high for my liking.
Motor 5 : Buehler 1.13.044.246 (52mm Dia 15V motor)
No Load - 0.4A @2650 RPM
Prop A - 3.8A @1750 RPM
Prop B - 4.5A @1550 RPM
Comment : Very powerful and quiet, and I like low current draw. Wish I had 12V version (-235 or -413) !
Motor 6 : MFA 800 with 2.1:1 belt drive
No Load - 1.6A @2150 RPM
Prop A - 5.3A @1750 RPM
Prop B - 6.6A @1650 RPM
Comment : Another very powerful setup. If you have space for belt drive in your hull.
I hope this is helpful.
