what my boat hopping on stright run

[kennyrach]

Hi all i just ran a 28" balsa wood boat that i build from Peells plan .the boat hop a lot when running straight . see video http://youtu.be/3R6GPvO3puY here the set up i am using In runner Brushless Motor B3656 KV2600
Aluminum adjustable stinger drive with 4mm cable set
Zipps kit 50 Amp Brushless Motor Controller
2S 7.4V 4200 mah lipo battery pack

[martin]

Move the cg foward to around 30% of the hull length in from the transom, it looks like you also have the stinger up to much at the prop end. Set the stinger level.

[kennyrach]

Move the cg foward to around 30% of the hull length in from the transom, it looks like you also have the stinger up to much at the prop end. Set the stinger level.

Yes your right the stringer is high but their no adj for so i make something to level it and what cg ?.I have the motor at at 3/4 of boat starting from transom to front

[martin]

Cg is centre of gravity, the hull should balance at around 30% of its length. Example if the hull is 28" long then 30% would be 8.4", so the boat should balance 8.4" in from the transom (rear of hull). You can then fine tune the balance from their but 30% is a good starting point.

[sundog]

Does this boat have trims tabs? Tabs can help prevent porpoising like that.

[Alexgar]

Cog, trim tabs and put your strut angle down a bit just my opinion

[Namba328]

Pictures????

[kennyrach]

no trim tab on it i may try and see it that help

[kennyrach]

boat has battery move up front it still came out of water at half speed .will try next week with the stinger drive angle down a bit and with Feigao 540L "Long" Brushless 540 11L 2,326 RPM / Volt 5mm Shaft motor.to run on two 2S 7.4V 4200 mah lipo pack wire in series

[kennyrach]

what size you think i need and how far out off back of boat .me thing 1 1/2" off back and 1 1/16 from bottom of boat

[Alexgar]

I thInk the bottom of the strut should be flush with the bottom of the sponsons

[sundog]

no trim tab on it i may try and see it that help

I'd go with 2" wide by 1-1/2 to 2" long tabs. Put them 1/16" (2mm) above the bottom of the hull (not flush). Adjust if necessary. Should tame it right down.

[Alexgar]

sun i was talking about the strut i started with mine flush and level and angled down just a little when my apparition was nosing up and bouncing

[sundog]

Yep, I'd try adjusting the strut down first. But if that won't fix it, tabs will.

[kennyrach]

Thank all for the info i will try all and see thank