"30 V hull porpoising

[wht73]

I did the COG test with the batteries installed and adjusted the stinger to parallel with the hull and the dam thing still does it!

Now what? Keep moving the batts forward? Adjust stinger down some? Play with trim tabs?

It has a M445 prop on it.

Also the rudder is VERY long. I think it's a speed master. Should this get trimmed down?

Any help would be greatly appreciated.

I want to be able to give this thing full throttle.

Thanks

Chris

[pond skipper]

Have any photos of the boat? I may be able to help some, I have a 33" seaducer that's very sensitive to its setup, my cog has to be set at 9.5 to 9.25" to run right, so I'm thinking that the boat you have may need to be anywhere from 8.5 to 7.75 from the back of the transom to run correctly. Take a straight edge or good ruler and mark the trailing edge of the rudder by laying it flat and using it like a continuation of the bottom of the hull and draw a line where they would intersect. Then measure from that line to the bottom of the blade to see the length from that point, my 33" hull has to have a 2.75" length between the two measuring points and that should be a safe place for you to start seeing as how your hull is shorter but I wouldn't go any shorter than 2.5". If you have a water pickup in the rudder then that's going to dictate a lot as well. Another thing is that you could have the strut too high causing it to propose, similar to what a FAST bass boat with an outboard if you don't trim it back down after slowing from a high speed run. The M445 should be a great prop on a 30" mono depending on the setup and voltage you are running, I'm guessing you are on 4s. Hopefully this helps you out. If you get a chance, post some photos that show the inside of the hull with everything in it where you would normally have it as well as photos of the hardware on it.

[wht73]

Here's a few pics. 20130704_072730.jpg20130704_072640.jpg0704130753.jpg

The batteries can't be moved rearward anymore. I did the "30 x 30% and get "9 which is where it balanced at.

If you need more pics , please let me know.

Thanks,

Chris

[wht73]

Those are 4k 5s pacs in there. Just for a couple blasts. I love the boat...just need to dial in. The battery hits the steering servo so that's the limit rearward.

[Southwest]

.......

[wht73]

0704130915.jpg Hope this works.

[Doug Smock]

Have you checked the bottom of the boat? You may find that there is a rocker in it.

[lenny]

H,
You also need a 3/16 gap at the stinger to prop drive dog.
I would put rx behind the servo,
To give you more room for the cell to move back if you end up having any torque roll.
Also would give you room for a gps to when doing speed testing.

[pond skipper]

The rudder is definitely too long for starters, is the boat porpoising at a specific speed or is it the entire time? And do as Doug says and check for a rocker.