.12 hammerhead (project speed)

[Hammerhead]

Hey Mike! The reason I put that piece of wood down between the sponsons is to support the inner walls of the rear sponsons and also serve as extra reinforcement for bringing the stuffing tube through the hull. I'm only using 1mm ply for this hull, so I need the reinforcent in stress areas. I could use a lot of epoxy instead, but it weighs more than wood. I tried to be as conservative as I could with the glue on this boat.

Hammer

 

[Propjockey]

Hammer, any mods to the V937 besides B/S?

 

[Hammerhead]

I don't know propjockey. You will have to ask MikeP. He gave it to me.

It looks like the tips have been tweeked a bit, but I'm not so familiar with the V series props. Might be that way from the factory.

Hey MikeP! Is it tweeked?

Hammer

 

[MikeP]

Not intentionally, they do bend easy. But it should be the way it came from Octura. The one Hammer has is not even balanced or sharpened.

-MikeP

 

[Hammerhead]

Thanks for telling me! I will balance it today.

Hammer

 

[Hammerhead]

Mounted the sponsons today. Everything went with out a hitch. Everything lined up just perfectly.

Put a light coat of epoxy on the inside to seal it.

I will seal the outside tomorrow with polyurethane sanding sealer.

I will paint it with Tamiya Fuel paints and give it a light clear coat of

clear polyurethane. Haven't decided on a scheme yet. I'm trying to decide whether to make it simple or go all out with the checkered flags and pin striping. Hmmmm

I finally got my 180 degree exhaust manifold in the mail. And the Rossi pipe that I will try. I also have a kyosho pipe to try out, too.

Any pipe length suggestions. What would be a good place to start, leaving me enough manifold to hack later?

Hammer

 

[_laxmasta2039]

hammer,

let us know how the kyosho pipe turns out.....i wonder if a company renowned for cheap plastic boats can turn out a nice pipe.....they sure know how to turn out the price tag of a nice pipe!! ;D [they're quiet pipe set is >100$ if i remeber right]

joe

 

[Hammerhead]

Hey Lax!

Both the Rossi and the Kyosho are .12 car pipes. The Rossi pipe was about 30 bucks and the Kyosho pipe was 20.

The Kyosho factory is about 10 minutes from my house. They have an 8 story building next to the factory. 3 floors are devoted to the developement of cars, 2 floors are for planes and helicoptors, 1 floor is for boats and sailboats, and the other floors are administration.

This should give you an idea about how much effort they put into the developement of boats. They test all their boats at the same pond I practice at. As far as cars, they have some really hot ones.

Hammer

 

[_laxmasta2039]

muxt be cool to see guys testing boats that arnt out yet........the quiet pipe im talking about is for .21 cars i think,

yours sounds like a good deal, if you think it's good enough to compare w/ a rossi than it's worth 20 bucks IMO.

joe

 

[Hammerhead]

I have no idea if it will compare with the Rossi pipe, but for 20 bucks, it's worth trying.

Here are some more recent pics. The first one is of the whole boat.

 

[Hammerhead]

This pic is of the sponson boom set up.

 

[Hammerhead]

This pic is of the turn fin spar

 

[Hammerhead]

This pic is a view from the transom. You will see that the transom is made of carbon fiber.

 

[Don Templeton]

"WOW" Hammer:

That's a fantastic design! I love those sponsons. At first it looks

like your balance point will be too far back but then when I take

another look the engine will probably set back a little farther than

most. so it should work out. Do you intend to cut any of the top

plate out for the manifold clearance or will it fit just like it is?

Also, the boom collars look great . Did you have those made?

Thanks,

Don

 

[TomMoorehouse]

yea Hammer..... loks great! did you buy CF plate or make it?

the sponsons look more americanized than the 90's a spar for the fin no big extension and a connector to the tub kinda thing.

i like it.... looks great.

what is the total length.... care to give a few size dimensions?

I saw you used nice overhangs past the bulkheads..... smart man you are! lots of extra strenght...... did you use the cross grain plywood for the top and bottom..... and what thickness?

 

[Hammerhead]

The top and bottom are made out of 5 ply 1mm Norway white birch, so the 2nd and 4th layers are crossed. I thought this would eliminate the need to go out of my way to make the surface plys crossed, like you mention in the directions for you ff.12 It is really thin though. I had to reinforce the area where I will put the stuffing box. These sponsons are also very light. They are way lighter than I expected. The left one only ways 2oz. The right one weighs a little more because it has binder extenders implanted in it to screw the turnfin spar on with. I also reinforced the inside where the turn fin arm is attached.

The boat is exactly 24inches long, and the tub is 2 7/8 inches. The body with the way it is in the picture above only weighs 14 oz.

The running surface of the front sponsons are 4.5 degrees and the rear sponsons are 2.4 degrees A little shallower than the 90s. The CG will be okay with the sponsons this far back, because when I put the engine in and all the radio stuff in the box, I can slide the battery back around to get the balance to fall exactly on the leading edge of the turn fin. This boat is pretty light in the front. If I made the sponsons any heavier, it probably wouldn't work right. I would have to use weights. Hopefully I won't have to with this one.

As far as cutting out the engine room decking to accomodate the header, I don't think I will have to. The header will be above the deck. I fitted the engine to see where I would cut the hole in the decking before I did it.

Thanks for the comments.

Hammer

 

[Hammerhead]

Oh! One more thing. I bought 1mm carbon plates. I glued them together to make the bracket for my rudder and turnfin spar. They are solid. I can't bend them no matter how hard I try. The lids for the radio compartment and the tank compartment are just the 1mm carbon sheet . The reinforcement for the engine mounts and the transom are 1mm

Hammer

 

[Don Templeton]

Hammer,

With all that info you wouldn't think I could have any other questions

but I do have one .

My tup height when level is 5/8" off the table, where is yours?

It's really great the way you share all that information with us. I

can hardley wait each day for you'r posts!

Thanks again Hammer,

Don

 

[_laxmasta2039]

can hardly wait each day for the posts?

Don, i can hardly wait for the day he's gonna hit the lake with it!!!

joe

 

[Hammerhead]

Hey Don! If I lay it on the floor, it won't sit level. The point on the tub square with where the front sponson's trailing edges touch the floor is 17 mm, and if you look at the transom, the depth of the slot between the rear sponsons is 11 mm. Believe me Lax. I'm more excited than you. I really want to see it on the lake, too.

Hammer