Rigger Tub Design

[Propjockey]

How much does the tub shape affect performance, and in what ways?

One of the latest crazes in rc planes is profile racers...with the fuselage having the standard outline, but only 1/4 - 1/2" wide.

What would happen with a rigger that had the same type of design?

 

[wswatzell]

Don't know, but I think you would hard pressed to blow it off the water!

questions about that type of design though.

1. what would keep the water out of the card?

2. how would you hold the tank in? the force of the water could rip the tank right off the hull unlike air

3. how would make a seeled radio box?

4. how would you mount the engine?

???

sure would be lite if you could make it work.

 

[Slideblues]

PJ the Gillmanator design was so narrow I had to file the engine lugs and it just slid in, Tom could not believe I wanted it that narrow, Past that dont know..........

 

[Don Templeton]

I remember a lay down 67 engine hull that raced in the Indy Unlimited one year and did quite well.

 

[Propjockey]

Hmmm.....

Snorkel for the carb....???

Custom tank

No radio box...low profile airplane flap servos mounted horizontally, out in the open...have to figure out how to waterproof everything....

Side mounted engine

 

[longballlumber]

WOW Don.....

I rember being at the Indy unlimited and seeing that boat as a kid.... It had a hole in the side of the tub so they could get the glo plug igniter on the plug.....

My first boat was a prize that my dad won at the indy unlimited.... It was a 3D demon 3.5 mono.... "The Pancake Boat"....... Remember those.... ;D

 

[MikeP]

Kinda like this

 

[ClayGlover]

wow mike where would you put the fin? ;D hehe, i know you're just showing what it might look like. a tub that long with a sponson spread so narrow... it would be hard to turn i'm thinking. you would have to change the geometry a little i guess lol sure looks light and fast like that though.

confidently waterproofing the radio would be the big challenge. maybe you could try corrosion-x type stuff, but you would still have exposed wire connectors ??? interesting idea bud

 

[Ian Inverarity]

I have thought about the side mounted angine layout and actually started designing one. But because of the engine mount lugs, the crankshaft centreline actually ends up being higher than for a normal mount. Because the majority of weight in an engine in quite low anyway, and the tuned pipe is fairly light the CG would not get much lower! Then there are all the installation and servicing isses to deal with. So I gave up... :

Nitrocrazed racing: Need to re-design the engines....

 

[Propjockey]

Actually Mike, that is the picture that got me to thinking about it.

Sponsons would have to be farther apart though.

 

[Ron Olson]

I remember a man who built some unique 'riggers years ago, back in the late `70's, early `80's that was trying to break the then 100 MPH barrier. His name was Jim Wilson, he lived in Paw Paw but spent his winters in Vero Beach, Florida. He had some 'riggers with the motors laid down way in the front of his boats with the fuel tanks over the CG. He built some of the best looking boats that I have ever seen, all in white and seamless looking.

Yes, waterproofing the servos is the easy part, some Gas boat racers have now almost completely eliminated radio boxes except for a small one for the reciever and battery pack.

One thing to remember, you do need enough boat to keep things afloat if it does die on the water.

 

[Don Templeton]

Hey Longballlumber,

Ya I remember those boats. Who was your dad?

That lay down boat used an exhaust throttle and venturi and belonged to David Lee. Ran pretty well!

Boy those were great races. Ya brung what ya got, anything from 20 mono to triple engine riggers and went for two days head to head. I raced in 7 of them and my best finish was 2nd. I don't want to talk about some of the other finishes. ;D

Don