Building a twin 40 inch rigger

[mm123521]

3 weeks ago I started scratching on paper and started this twin rigger.
Powered by two CC 1518 (or are they 1520's? -- its the 1800KV one).
Got a pair of GenAce 5300MAH, 6S batteries, one in the front and one in the rear.
ESC's are T180's.
Will be turning a little under 40,000 RPM, through a .093 wire drive.
447 (right and left) props on the other end of the wire drive.
Hull is 40 inches long, not including the rudder and props. Beam is 25 inches.
Sponsoons are patterned off a JAE 45, but are 3 inches wide, insted of 1.5 inch, the hull is scratch designed.
Hull is 5 inches wide to accomadate the side by side motors and 2.75 inches tall.
Notice the side wall motor mounts, it was the only way I could figure to get the motors in and out of a 2.5 inch wide hatch.
The motors will bolt to the side of the tub. Tub sides are 1/4 inch , 5 ply birch , bottom is 1/8 , 5 ply -- trying to build for the crash.

If the hull works, arodynamicaly, then this thing might hit 80 to 90 MPH ?? - I hope.
There is a lot of guessing on the Arodynamics, and balance -- I hope it works.

Mark100_0145.jpg100_0146.jpg100_0147.jpg100_0148.jpg

[Boaterguy]

haha, never seen a twin rigger before, congrats on squeezing twins into a tub.
I can't guess on speed though.

[Jacked1]

I like it a lot!! I am planning something similar for the future!

[mm123521]

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I like it a lot!! I am planning something similar for the future!

Jacked1,
I have AutoCad drawings of this one, but you might wait and see if the hull works first.
I figure 3 more weekends till this one is ready for the water.

Check out the sponson booms.
They ar 1/2 inch, .049 wall tubing.
I threaded the inside of the tube and made a threaded "screw" to hold the sponson on.

[Jacked1]

That is a cool way to do that! And I will deff not be close to starting mine for quite a while as I have 4 empty hulls as it is for the summer. I am really looking forward to see how it runs and compares to single hydros with the same power levels.

[Grazacind]

Really looking forward to this build as I am setting up at the moment for my my twin rigger. Looks great by the way. My only difference I think will be a setup more for SAW racing.

[mm123521]

A little more progress:

Glued the sides, bottom, transom and bulkheads in.
Notice the blunt bow. I will make several, bolt on, nose pieces so I can aduust the aerodynamics.
Check out the foam bow reenforcement.
Look at the foam, ESC holder and battery spacer. The foam holds the ESC and provides floatation. The foam block is split down the middle so the halfs can be removed through the hatch.

I did a balance test and it looks like I can get the CG behind the turn fin, if I locate the rear battery aganst the transom.
I have the "stingers" mostly machined out.

This thing should come in at 14 pounds RTR.

Mark

[Brushless55]

Sweet, a twin electric rigger!

[Fluid]

Cool project. But all current successful twin fuel riggers I've watched race use LH props, not counter-rotating. It was found that turning was poor with counter-spinning props - at least for racing. Using LH props opens up a LOT of possibilities. It's easy to go both ways, whichever works for you.



.

[mm123521]

Fluid,
Thanks for the tip!
With wire drive its easy to switch rotation.
I spent the evening lining up the drive line.

The struts are custom built. I still need to "fancy them up" with some lightining holes and polishing.
Coupler and motor mounts are home built.

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[mm123521]

I have "roughed out" a turn fin from stainless steel plate -- very stiff, but a little heavy.
It mounts through the boom tube - it suits the CG and gains support from the tube.
The split clamp is welded to the turn fin - very strong.

Mark

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[urbs00007]

rigger

pics of 12-s rigger