Newbie with a U-47 - Tech question....

[cskyhawk72]

Hi everybody.... first of all, I want to give you all a big "Thank God!!" for this website! I hope you can all help me out here though....

Anyway, I just got myself into a Robbe U-47, got it all put together, just have to install the radio gear and fix up the rear linkages. And then there's the dreaded front dive planes.... I wasn't at all impressed by the Robbe dive system, and didn't even install the tube thingie. I'm planning on replacing it with a servo. Does anyone on this board have any experience with this mod, and if so, do you have any pics of the mod? I'm terrified at the though of drilling through the front pressure dome, is there any way around that? And where can I buy replacement bellows for the pushrods?

Well, thanks for the help!!!!

[bob_eissler]

There have been several methods

There have been several methods used. Some seal the servo & have it outside of the watertight chamber, with the wires passing thru. Some have a pushrod out the back with a flexible linkage going up front. There is a build on subpirates that does that. It is unproven as yet, but I am using magnetic coupling thru the walls. The servo moves magnets inside which move the outside magnets attached to the bow planes. I'll try to take pictures tonight, it seems alright but the boat hasn't been in the water yet. There is no hole in the watertight chamber to leak and nothing to uncouple when opening the chamber. The boat uses RCABS for active diving, too.

[bob_eissler]

I have added a few

I have added a few pictures on my homepage (bob_eissler)to help explain things.

[Guest]

I enjoyed looking at your

I enjoyed looking at your progress on your homepage. Good luck with your project. Your final RCABS switch may be a good solution for you, but unless you have end point adjustment for your servo travel, you could burn out your servo prematurely, as I did at my first attempt, using a servo arm, instead of using a modified servo wheel, as a cam. With the servo wheel/cam approach, the servo need not be straining to move more, while you are activating your switch and valve, as it can slide beyond the already activated device, to the end of the servo travel.

[bob_eissler]

Yes that can be a

Yes that can be a problem. I am using a Futaba PCM radio that allows for end travel & trim adjustment. The transmitter has a 3 position switch for that channel which works perfect.
Good observation. You can't easily tell from the images but I am supplimenting your bladder with a cut down bicycle intertube which runs down the sides. I think it will run with the deck higher on the surface & extra bouyancy can't hurt.