G. Finlay 1/16th scale Hydro

[billf1973]

hydro3 002.jpg
Hello,
I am having a hard time getting my hydroplane to run correctly. It is powerd by a 3300kv, Esc is a seaking 90amp, Prop is a 1.34x2.06, and a 2s 3300mAh 30c lipo. The boat wants to go, but when full throttle is applied the front of the boat dives down. I have lowered the stuffing box about a 1/4in since it was level with transom. Still get the same result. Any help would be Great.

Thanks,
Bill

[Diegoboy]

can you post a transom pic?

[billf1973]

Diegoboy,
Here are a few pics of the transom.

Thanks,
Bill

SAM_3292.jpgSAM_3293.jpgSAM_3294.jpg

[Diegoboy]

How much strut angle is there + or - ? Where's the center of gravity? and What size prop is that?

[billf1973]

Not sure of angle. I know it is about 1/4 inch between stuffing box and bottom of hull. CoG is up in front of motor where lipo goes, and its a 35mm prop.

[Diegoboy]

Can you take a profile picture of the transom please?

[billf1973]

That is 1/4 inches down at transom.

[Diegoboy]

Strut angle: A strut has a positive angle when the prop shaft points upwards, far from the water surface. In this situation, the transom is pressed down. A negative angle occurs when the prop shaft points down, towards the water surface, raising the transom. If you imagine the boat supported on a transverse shaft that goes exactly through the CG, it's easy understand that, when the transom is lowered the bow goes up, reducing the wet area. The contrary occurs with a negative angle for the strut. Although apparently we could use the strut angle to correct any incorrect attitude, the truth is that the neutral angle is the ideal, just a few degrees off are allowed to adjust the wet area. If more than 2 degrees are necessary, something else should be wrong.

[billf1973]

May be more then 1/4in.
SAM_3296.jpgSAM_3299.jpgSAM_3301.jpg

[Diegoboy]

Does she run a solid prop shaft?
That seems to be too much negative angle

[billf1973]

No its a flex shaft .130

[Diegoboy]

Level that prop angle first.

[Heath M]

Try setting ur strut the same depth as the sponsons with about 1 degree of negative angle. Also straighten the rudder to 90 degrees, it's got way to much negative angle.

[billf1973]

When I first set the the strut it was level with the bottom of the hull(touching the hull). After running it for the first time I knew the prop needed more down angle. Moved the prop down and tried it again, same results.

[billf1973]

I will be changing rudder angle and prop shaft soon. Thanks guys!