.12 hammerhead (project speed)

[Hammerhead]

I finally got tired of sittin' around not building anything.

I have been reading a lot about .12 riggers. They are very interesting and seem to be more challenging than the big boats. I got a set of the ff.12 plans and learned that a lot of the materials I will need to build it were impossible to get in Japan. When I build the ff.12 I will make it by the plans, to the "T".

In the mean time I will build a Hammerhead 12 with materials that are available.

This is what I'm looking at .

24" long. 2.8" width of hull. Target weight of 1.7lb or less.

I will run a TR.12 turbo that has been tuned and rebuilt with a water jacket flywheel and drum carb and less pilot shaft. Should scream.

I will have all the running hardware except the outer tubes for the sponson booms and the turn fin bracket made of high grade light weight titanium. These parts include the stuffing tube, rudder assy. strut assy, turn fin. tank, engine mount. and all bolts.

Haven't decided on the servos yet. Small high torque X 1 and a normal torque X 1. I'm a Futaba dude, so if you have any recommendations. I would appreciate it.

I started with the framework for the radio box and I partially finished the sponsons today. I will learn how to post pics soon, and give you guys a look. All comments and

suggestions welcome

Hammer

 

[Don Templeton]

Well Hammer,

If it comes out at 1.7 lbs like you say, I think I'll just go home! ;D

Actually, I'm really looking forward to see what you come up with.

One question-Does the regular crank for the TR fit the TR Turbo?

Don

 

[Hammerhead]

Well, I'm just going by what others have said about 1.7 being an optimum weight. If it ends up 1.7 I well have met my target, and keep in mind, it is only a target. And,... Please don't go home if I do

Yes you can replace the pilot shaft with the normal one in a few minutes. Had to have a water jacket and flywheel made for it, so I can rope start it. Don't want the extra weight of a recoil. If you take the carb off the drum version normal TR it will fit right on to the five port TR. For those who don't know, the five port turbo TR is the black cased one, and the Normal is silver cased. The Normal version comes with a normal shaft and you can get either the slide carb version or the drum carb version which is ideal for boats. The five port TR sleeve and piston can slide right into the normal version and the turbo head will fit on it, too.

Or,... you can change the crankshaft and carb of the TR turbo and basically get the same engine at relitivaly the same price. I prefer the black case, so I will go with the later version.

 

[MikeP]

Hammer,

Try a Futaba S3102 (21g) for rudder. I ran one all summer in my .21.

-MikeP

 

[Hammerhead]

Thanks a lot Mike! I just ordered two of them. I think 3.1 kg torque is plenty for a .12. The dimensions are perfect for the radio box's limited space. I'm thinking of making the turn fin support bar out of 3mm carbon. You used carbon for the .21 CF, didn't you? What thickness would you recommend?

Hammer

 

[MikeP]

I made one out of 10 layers, it's 3.1mm. It will flex some without the third boom. If you are buying 3mm already made It will be alot stiffer. It would make a difference how wide you make it. If you use the third boom it could be alot smaller.

I would look at titanium first. Small, light, no flex, no third boom.

-MikeP

 

[_laxmasta2039]

another choice to look @ is arrow shafts....

coming from a bowhunter [yours truly] i think an aluminum hunting shaft would work pretty well, a carbon fiber shaft would be great, they are extrmely light and stiff. also, you could the stub of a larger shaft as a sleeve at the ends for support........

joe

 

[Hammerhead]

Hey Joe! I got a 6mm carbon fiber rod that is 1 meter long. I will use it for the booms. There will be enough left over for a third arm, but this time I will try to get my CG to where I won't need to use a third arm.

It would make it all that much lighter.

Thanks Mike and Joe.

 

[MikeP]

Hmmm, are we talking about the third boom or the turn fin mount?

My support bar is 7mm same as the sponson tubes.

3mm solid might be good but not hollow. The problem with the carbon rods is mounting them, 3mm I think would be kinda fragile.

I still think titanium fin and mount no support.

-MikeP

 

[_laxmasta2039]

cool,

let me know how it works out- i've got a bunch of old arrows lying around without any use, and it doesnt hurt that they've got a camo pattern on 'em!!

 

[MikeP]

Hammer,

I found some posts way back in the .12 rigger topics. Rad Racer was running a Frank Bonnano hull at 27oz. (1.6 lbs). Some one else stated that Franks boats were 1.5lb.

www.intlwaters.com/yabbse/index.php?board=1;action=display;threadid=131;start=45

-MikeP

 

[TomMoorehouse]

hummm franks boat looks like it could be lighter than mine. But we have some different opnions in construction methods... could make mine lighter but I would rather have it last longer..... but hey.... I need to get mine on a scale. maybe i'm wrong and it is under 2 lbs :

 

[MikeP]

I agree with you Tom, my .12 is a little heavy. I keep thinking that you could build it like a R/C plane, couple pieces of ply and the rest balsa. They hold up well but only take 1 crash. Tom needs to get his in the water.... then I need to go back to the drawing board my speed isn't there. I need to shed about a 1/2 pound off the back end.

-MikeP

 

[Hammerhead]

I got a call from the post office!!! My hardware is here ;D

I will call them, and have them deliver it today. Happy me.

It ended up costing 110 dollars for everything except the Tank and Engine mount. Not bad!

Hammer

 

[TomMoorehouse]

what hardware did you get hammer..... i had a hard time picking what i was going to use!

 

[Hammerhead]

I had it custom made. It is made of titanium. Got a good deal, because I'm good friends with the guy who made it. I paid for the materials only. I will try to post pics tomorrow. It weighs almost nothing. I couldn't get the titanium pipe for the stuffing box, though. I will have to settle for brass, or aluminum. It is really beautifully made.

Hammer

 

[topfuel443]

Hammer, have you started the construction yet???? Let see some pics. I build my own riggers also and am getting very interested in building a .12 Ive got a 1/8 scale gas car that i used to race with a really hot Parris/Picco engine that would look good sitting in the hull of a rigger! ~ James

 

[Don Templeton]

Hammer,

You keep going like this and you'r going to get to that 1lbs/7oz yet. ;D

 

[Hammerhead]

Hey Guys! I got the second attempt at sponsons almost finished, and the tub frame is finished. I will get some pics up tonight. If I can't figure it out, then I will send them to MikeP to post for me.

Top fuel! This is my first attempt at something this small. It seems to be going together very well, thanks to a lot of ideas that I copped off the other members here.

I went to the pond today, and there was a guy with a .10 O.S in a rigger. It was really fast. I was suprised. Can't wait to get mine out on the pond and blow him off the water.

Hammer

 

[TomMoorehouse]

pictures hammer!!! got the see that titanium hardware!