Bronco twin battery, prop, and power pack?

[randyrls]

I have a Power Pack "B" twin for my Bronco. WHAT A BEAST! Flies straight and level at only 20% throttle. It will accelerate going STRAIGHT UP at full throttle! With 9x4.5 props it will climb right out of my hand, all I have to do is let go. That is the good news. The "B" twin needs a 3700 3S 30C battery to supply current draw. 2200 3S 30C doesn't supply enough power. I want to use 2200 3S 30C as I have more of these for other planes.

I want to reduce the current draw using one of these scenarios:
1. Use 8x4.5 props with the "B" motor to see if the current draw goes down enough for a 2200 3S 30C to supply enough power. I have a watt /current meter.
2. Use 8x4.5 props with "A" motors to see if flying characteristics are good enough.

I have a Power Pack "A" twin and some spare 8" props on order now. The 8" props will keep the props from hitting the ground (grass) when landing.

 

[Mr Man]

I have a Power Pack "B" twin for my Bronco. WHAT A BEAST! Flies straight and level at only 20% throttle. It will accelerate going STRAIGHT UP at full throttle! With 9x4.5 props it will climb right out of my hand, all I have to do is let go. That is the good news. The "B" twin needs a 3700 3S 30C battery to supply current draw. 2200 3S 30C doesn't supply enough power. I want to use 2200 3S 30C as I have more of these for other planes.

I want to reduce the current draw using one of these scenarios:
1. Use 8x4.5 props with the "B" motor to see if the current draw goes down enough for a 2200 3S 30C to supply enough power. I have a watt /current meter.
2. Use 8x4.5 props with "A" motors to see if flying characteristics are good enough.

I have a Power Pack "A" twin and some spare 8" props on order now. The 8" props will keep the props from hitting the ground (grass) when landing.

I’d vote for sticking with PP B with the 8” props. ON PP A, it would definitely draw a lot more amps, and probably fry the motors.

 

[randyrls]

I switched Bronco props from 9x4.5 to 8x4.5 Kept the "B" power pack. It seemed to fly ok but as I came in to land a gust tipped the plane over, caught and ripped the outer section of wing. I repaired the tear in the wing . I want to see if that improves characteristics.

 

[Piotrsko]

Thought that's impressive? Try twin "C" with 11" props but you'll want functional rudders unless slight sideways isn't a problem. Does everything a quad will do, didn't try differential thrust.

 

[randyrls]

Thought that's impressive? Try twin "C" with 11" props but you'll want functional rudders unless slight sideways isn't a problem. Does everything a quad will do, didn't try differential thrust.

Piotrsko; I would be **TERRIFIED** of those big spinning hand/finger eaters! I hate reaching between those props to connect battery, so I added a switch to the rear part of the plane. My friend offered to help launch it and commented on the prop wash.

Does yours have landing gear? The 9" props hit the short grass of the field and even the 8" props touch the grass.

I wanted something unique so I built the "A" tail (aka inverted "V"). Our field has a line of trees behind us and the wind creates "rollers" over the landing field. It requires careful handling when landing.

 

[Piotrsko]

Had: belly lander T tail. Long spindley LG and foamboard is a poor mix. Have wrinkled remains somewhere in workroom. Props were stronger back then, you could round the ends and it wouldn't disentegrate, but unpowered landings don't hurt even the cheapo new ones.

Bit of advise: flies really tail low inverted, don't do low inverted grass mowing.

Props don't cause me issues with hands because I don't go anywhere near the props powered. Your esc's should need arming after every power up, so the front should be safe until then. Ymmv

I have a discussion here about my GWS VERY SLOWSTIK eating ten foot of oak wainscotting one oops day. Very even prop strikes for ten foot.