Twin wing 1/12th scale

[cyberhoops]

After sinking one boat it was time to build something new for LSH racing this season. I happened to have a set of Roger Newton plans for the 1993 twin wing Circus Circus so I had them reduced to 1/12th scale and started building.

About 10 days later I have a mostly completed hull using plywood and pink foam construction.

It pretty much follows the Newton plans except I left off the turbine air intake. For the sponsons I did not use the stringers from the plans, but rather just the bulkheads for shape and then chunks of pink foam that were sanded to the profile and covered with 1/32nd plywood. The non trip is also filled with foam, so this boat is not going to sink. The hatch is carved balsa and then fiberglassed with lightweight cloth. The overall weight before hardware is 1lb 10oz.

The hardware plan is the UL-1 motor and ESC, Solinger drive hardware for the strut and rudder and a .150 flex drive. There are still a bunch of details to finish - like a waterproof radio box, servo installation, some method to hold down the cowl, rear wing cross braces... etc.

The paint and decals will eventually be in the style of the 1991 American Spirit - red/white and blue with stars.

I wanted to have the boat for the first PSFE race next weekend, but I don't think I will make it, but it has been fun to build.

[Doby]

Looks nice. I like the idea of the built in, form fitting flotation!

[cyberhoops]

The pink foam even becomes structural. It reduces flex in the boat and it gives a lot more surface area for glue when applying the plywood skin. It also sands really nicely.

[Darin Jordan]

This is "Wood Over Foam" contruction and it's a nice and fairly easy way to build a boat. It's the technique I used to build my "Banzai HydroSport 28" a couple of years ago...

Check this thread for some construction pics that may be helpful in future projects:

http://www.offshoreelectrics.com/forums/showthread.php?t=609&highlight=Hydrosport+28

Nice work, Jim... Doesn't look like fun fitting gear in it, but it should be fun to watch on the water...

[cyberhoops]

I have some paint on the boat now, and the hardware is here from Offshore, so unless something goes really wrong I think it will be ready for the first race in 4 days.

For the cockpit hold down I am going to use a wing hold down bolt from one of my airplane projects. It was a bit tricky getting things to line up, but I think it will work. That is what goes into that hole in the cowling. The American Spirit decals are next...

[edit] - and the decals are on except for the vertical tail decals.

[Ub Hauled]

this looks great man, make sure to post videos too!

[cyberhoops]

Here are the last couple pictures now that the boat is complete and ready to run - and thanks go out to Steve Vaccaro at Offshore for quick delivery of a cooling jacket for the UL-1 motor. I thought I had a jacket that would fit... but noooo. Thankfully Steve came through with some fast shipping to get a jacket that would fit.

Final weight: 4lb 4oz ready to run. Not the lightest boat ever, but ok.

I am excited to go racing.

[tth]

Beautiful boat and good job on the build.

[NativePaul]

Very nice, good paint job too.

How big does it turn out at 12th scale? I'm currently doing a very similar project, I was torn between that twin wing unlimited and the miss bakers equipment twin wing unlimited light, I went for the light in the end but without the rear wing and turbine intake it looks the same, mine is 1/32 plywood over foam and is 32" long, I have solinger hardware for mine too, it will be interesting to compare the weight when I've finished.
Here's what I have so far.

[cyberhoops]

The size of the twin wing is roughly:

Length: 26 3/4"
Width: 15
Tunnel width: 6 7/8
Height: 4

It looks like you will have a wider tunnel. The other thing I notice is that my front and rear wings were not solid through the body. I think that helped with the hardware install. There was enough vertical room in the body to do things like put the ESC under a tray for the battery and mount the servo vertically to save some room for the reciever.

It will be interesting to see how the unlimited light turns out. It looks very good to this point.

[NativePaul]

yeah the width is what swung it for me, they took it apart in '95 and added a bit to each wing to make it wider, I will have a cut out in my front wing too, just haven got that far yet, I think I can get away with keeping the rear one intact, there'
s not a lot of stuff to go back there.

[cyberhoops]

The twin wing had a first race today and I think it ran exceptionally well. Overall it finished 3rd of 8 boats in the race - but it was quick and stable.

We ran the heats with an X640 prop - and while it sprayed a lot of water though the twin wing to get up on plane, it worked just fine.

We did try the Grimracer 4258 3 blade prop, but the boat would not get up on plane with that prop. Maybe it would have worked with some strut adjustment, but we just switched back to the X640 and ran with that.

I don't think it could have gone any better for a first time running the boat.

[JimClark]

Here is one of mine from today







The whole gallery is herehttp://jimclark.smugmug.com/gallery/...01255551_vzghx

[Stealth Assassin]

Very cool! I like to see scratch builds.


D

[AndyKunz]

Nice boat! Nice picture, Jim!

Andy