Fun New Project: 100 Lbs Of Thrust In A 10 Lb Scooter

[bmazin]

Thrust was measured by looking at the current draw and comparing it to the propeller simulations (which were pretty accurate for Jetboots) - I didn't get out the fish scale, but I think we were at least at ~80 lbs based on feel. As to the power density, that was kind of the point of the project! It drains its batteries at 10C, pulling something like 2200-3000 Watts (4-5 hp) for 5 minutes. It is pretty hard to hold on to - in one of the videos you see me using a tow rope. You definitely need two hands.

 

[lucca brassi]

you use direct driven motor and reduce rpm via controller or you use planetary gears reductor ? (which ratio ? )

 

[herman]

Again, the numbers don't sound practical . Assuming a 12v battery, the current would be in the 200 to 250 amp range for the wattages you state. Your horse power calcs are off too....2200-3000 is 2 to 3 hp. That amount of current is going to cause a lot of heating unless you have some large conductors. Care to share the battery and motor type/model?

 

[bmazin]

It is a 24V motor, running about ~110 amps. 750 watts/hp, so 3-4 hp is probably more accurate. It does use a gearbox and brushless motor - efficiency just isn't good enough without one at these RPM.

 

[Reku]

That looks fun. Knowing my luck I'd chop my hands off in the prop though