Active tunnel wing for cat

[bonewar]

Tunnel wing operated by a gyro/servo , still in the drawing board stage. What i am trying to do is push a H&M Maritimo to its limits . Anyone had a go at this, i know the full size boats use to have them but where banded . Thanks Bonewar

[Ub Hauled]

I am glad to see that you are trying it out... I have a Gyro and just need to find the "lab rat" to use it...
Good luck, keep us posted.

[crabstick]

DAMN! I wanted to be the first one to do this LOL.

Nice one, been thinking of putting one in my new 53inch Petrol cat Im getting this week!

[Steven Vaccaro]

What effect does lowering the wing have on the hulls ride? Lift?

[Gerwin Brommer]

It's been done before.
Servo's mostly not fast enough.
And the gyro is responding late.
It will not prevent from blow-overs.

It MAY help to keep the boat leveled and stay on the water,
but if the boat looses contact with water the flap won't do anything.

[crabstick]

What effect does lowering the wing have on the hulls ride? Lift?

From my understanding of the use on the full size boats, they create lift in the rear to keep the front planted and land smoother off big jumps.

@ Gerwin - I wonder if anyone has done one with an AVCS Gyro i.e. GY401 and a Fast digital servo. Theres Gyros and then theres Gyros..

[Ub Hauled]

I think that even if it helps the boat stay in the water longer it's an achievement, that's what one needs to get the extra few mph in... go ahead and try it man!

[bustitup]

just keep a steady hand on that dremel BW

[Gerwin Brommer]

Bonewar & Crabstick,

It's worth trying...........
Big round of applaus for everybody who dares to think out of the box.
As far as I know it hasn't been tried on a Maritimo.

[bonewar]

which gyro to use

THANKS FOR THE REPLIES GUYS, My take on this is , when the hull gets to the level where the running gear is at its peak performance and no more speed can be achieved buy the set up , This is when the wing will come into play , just like UB said the extra mph is what I'm trying to achieve on top of a very fast setup. CRAB STICK mate i do not know much about gyro's , what would be the fastest and best for this idea?? GERWIN I'm shaw you could buy a digital servo that would be fast enough for it to work. So anyone with ideas on the right gyro/servo to use in this application?? THANKS PEOPLE BONEWAR

[crabstick]

I would go for a futaba gy401 and a futaba 9650 servo. If you make the actuation system like a cam and actuate it with a horn on the camshaft shouldnt load the servo up much at all, you could I guess go for a larger fast digital servo for a bigger boat

[bonewar]

Trim tabs

Got another idea, How about putting a trim tab on each of the spoonsons transom and having them run be the gyro/servo , Or just using the TX to control the height of the tab( manually)? Or maybe using a channel mixer to work both of the tabs? Any ideas here are very welcome. Thanks people Bonewar

[crabstick]

Got another idea, How about putting a trim tab on each of the spoonsons transom and having them run be the gyro/servo , Or just using the TX to control the height of the tab( manually)? Or maybe using a channel mixer to work both of the tabs? Any ideas here are very welcome. Thanks people Bonewar

Great idea, I know of a gas boat that has a mix to control full down trim tabs in a turn and they come up in the straights. From my limited knowledge in fluid dynamics I have read that hydrodynamic drag is about 10 times that of aerodynamic drag on the same surface area creating said drag (if that makes sense), I think if you can adjust the hulls attitude via aerodynamic drag then you will maintain more speed. Sounds good on paper anyway.

[Jesse J]

Dude, great line of thinking. From running my cat with the newly designed and installed tunnel flap, I would rather have control with a third channel the attitude of the flap than a gyro. Not sure what your end goal is, but I think that a good point was made about the quickness of response time needed to be self correcting. More realistically, I would like to have a servo adjust my tunnel flap as water conditions change, wind direction change, turn radius changes and as I add more voltage.

In the end I would imagine you would need to build a pretty big one to have the kind of action you are looking for. Don't misread me: I am not saying it won't work, just expressing my intuition. Personally, I would stick to the tunnel and not mess with the transom tabs; I think the air under the hull is the best place to play (along crabsticks line).

I'll be watching to see how this turns out, verrrrry interestink.

[marko500]

I've been thinking about this for awhile also. My thinking is a wing on the bow between the sponsons. The pivot point would be set back on the wing a little not right on the leading edge. By changing the angle you could either pack more air into the tunnel or deflect some up over the deck. I was thinking like Jesse said to adjust to water and wind conditions more then to be self correcting. I realize this won't prevent blowovers but more to adjust ride attitude. Mark