AD2 setup question

[Ken_NJ]

I'm having a bit of a dyslexia problem today.

I enter setup mode, then save the neutral position of the aft planes. Next step is to command a full rise and press the button to save the setting. A full rise would be the tail end of the aft dive planes pointing downward?

Don't know why my brain doesn't get this part today. Maybe poor sleep.

[RCSubGuy]

Backwards, Ken. Full rise on the stern planes would see them pointing upward...

The rest looks good to me.


Bob

[Ken_NJ]

But but, if the tail end is up like you say Bob, the aft end will dive deeper. Not rise. Right?

If the boat is pitched bow down, the aft planes need to drive the aft end down to level the boat, hence tail end of aft planes are pointed up.
If the boat is pitched bow up, the aft planes need to drive the aft end up to level the boat, then tail end of planes pointed down.
So based on that, to rise or surface the boat the tail end of the planes need to be down.

That seems right in my mind, but my mind may be just plain mixed up at the moment.

[SubICman]

It's all about the moment arm of the planes. The stern planes need to point trailing edge up to bring the bow up. The water flow over the surface causes the stern to squat and the bow to point up. Opposite for dive, just like you described. With the bow pointed up or down, the larger plane surface, the hull, will cause a depth change. This is reversed for bow/fairwater planes. They need to point trailing edge down to pull the bow up.

If you want to surface or change depth, you have to drive the boat up or down. The AD2 is a pitch keeper, not a depth keeper. It will keep the boat nice and level. Depth keeping is done with variable ballasting and planes use, or some other electronic gadget that has a pressure sensor attached to give depth feedback to drive to.

[He Who Shall Not Be Named]

But but, if the tail end is up like you say Bob, the aft end will dive deeper. Not rise. Right?

If the boat is pitched bow down, the aft planes need to drive the aft end down to level the boat, hence tail end of aft planes are pointed up.
If the boat is pitched bow up, the aft planes need to drive the aft end up to level the boat, then tail end of planes pointed down.
So based on that, to rise or surface the boat the tail end of the planes need to be down.

That seems right in my mind, but my mind may be just plain mixed up at the moment.

Look on the vehicle as a teeter-totter. Near the center is the fulcrum; the point about which the hull rotates in pitch and yaw. Push the ass-end down, the pointy-end goes up. Just like a teeter-totter.

Your 'tail-end' is properly called the control surfaces 'trailing-edge'. When the stern planes (control surfaces which produce force about the pitch axis) TE points up, the force applied by the planes pushes the ass-end of the boat down; when the TE is pointed down the stern planes push the boats ass-end up.

Duh!

Don't make me come over there, you incredible pain-in-the-ass!

Good looking weathering job there, Ken. Finish that beast!

David