Kevlar .12 Rigger Project

[TomMoorehouse]

test reply

 

[Don Templeton]

MIke,

I never did hear. How happy were you with the performance of your last .12.

Don

 

[MikeP]

Don,

I was very happy with the performance. The design of the hull worked good. There were some things I didn't like.

The light weight construction with ply was a little fragile.

It was made out of wood.

It had a small battery and didn't have an on off switch(bad combo)

it would be ok for racing but bad for playing around.

The left side rudder in front of the prop was probably flooding the prop in the turns.

Non adjustable strut left nothing to play with, it would be nice to raise and lower the rear to adjust the AOA of the front sponsons but I don't think it needed it. It was pretty close.

The Kevlar boat has all these things fixed and is at the same weight.

If it runs as good as the wood one I will be happy.

-MikeP

 

[wswatzell]

So Mike,

I know you are busy with the composite tunnel, but have you had a chance to run this one yet?

 

[Hammerhead]

If you're not going to run it, send it my way. I have a brand spanking new NR 5 port looking for a new home. Just kidding. Looks beautiful. Love to see some videos. I'm starting a new HH.12 that will be a little bit narrower. and 2 inches shorter. Gonna put the sponsons farther forward. Probably won't be as user freindly as the kit, but you have to get crazy sometimes. By the way, Mike. About the flywheels. Did you get my mail. Never heard from you after that.

Hammer

 

[MikeP]

Hammer,

I knew you were busy and didn't want to bother you. I had Wade draw some plans for a flywheel. I have been collecting some tooling for my lathe and now I ready to make flywheels at home.

I should have some vids next weekend if things go as planned.

-MikeP

 

[Hammerhead]

Hey Mike! If you can, get your mits on the new Nova Rossi NS5 .12. It screams. 43500RPM at 1.6 hp. Mount and shaft are the same as the .12 O.S TR-PT. It has fins all over the case, so you will be able to cut off a lot of the heat sink to reduce weight. Check it out.

Hammer

 

[wswatzell]

Hey Mike, have you had a chance to get her wet yet?

Can't wait to find out how she ran! ;D

Wade

 

[MikeP]

Finally got the boat on top of the water it was really fast and light on the water. It's a bear to launch. I found that a half throttle launch would keep it going then it would work itself on top and on the pipe. It really needs something in the rear to help it up. (about 50% launch failure)

-MikeP

 

[Ian Inverarity]

Mike,

I was a bit worried that launching may be a problem with no rear sponsons and very little rear tub area. Maybe enclosing the stuffing tube in a rear sponson?

Ian.

 

[Don Templeton]

HI Mike,

I assume you've tried a V937 for lift. Trouble is you probably wouldn't

want that once it's up. What about a short center sponson that doesn't go all the way to the transom? You know, I've seen a lot of very good riggers that didn't launch well. Are you launching it yourself or do you have someone else do it for you?

Don

 

[MikeP]

Here is how I got it to go,

About half throttle toss it in easy and let it plow through the water and slowly throttle it up and away it goes. It will only get up with the x438 prop.

Runs nice when it's up I think it's a keeper, just need to get a little sponson attached to the back.

What would you think a single rear sponson on the left side only woud do? Thinking a little support from the left side in the turns would be good.

-MikeP

 

[Don Templeton]

That sounds like a plan to me Mike. However, I would keep it pretty shallow. Maybe 1/8" higher than the center of the shaft. :-

How does it perform in the turns? Or, is this ment to be a SAW boat.

Don

 

[MikeP]

It had a little hop in the turns, but I didn't have enough time to figure it out. Mostly just broke in the motor. I don't want it to be a saw boat.

Going to keep after it, I can add what ever it takes to the rear.

-MikeP

 

[MikeP]

Well, I think I ruled out the the back end of the hull, Now I am going to change the front sponsons. It looks like they don't quite lift out of the water. The curved tips and narrow size seem to be plowing the water. The sponsons with the wide tips seem to pop the boat quit easy yet still have a narrow ride surface. (HH.12 design).

This boat is quick! It just needs Viagra to get it up.

Mike

 

[wswatzell]

Mike, I think a wider front sponson ride surface would be the ticket. Looking back at the pics of the hull, I noticed that the hull doesn't appear to be able to generate much aerodynamic lift. This is good so it won’t blow-off as easy, but it won’t help lift itself out of the water either.

I still think it is the coolest rigger I have ever seen.

just my thoughts.

 

[rhomodel]

Mike, as you might have read I made a cigar rigger for a gasoline boat. Like you small rear but I do not encounter the problems you describe. First time out engine just kept on stalling when launched, I build much wider sponsons and made a better carb shield ( gasolines have side mounted carbs) and it ran much better. I had engine problems that prevented it to get full throttle but at half trottle it would run around and lift the rear, even with a propshop 7015, which is notorious low lift. I added a third sponson in the rear after reading your story but that made the boat hop around. removed it and boat would run much more calm without too much hopping. I'm surprized how well it turn. If I may advice you: make sponsons wider by about 60 % with shallower angles on the outside and add a ride plate. The wider sponson will help you launch the boat easy and the ride plate reduce the wetted area when running.

Julius

 

[MikeP]

Thanks, for your thoughts on this. I feel alot better knowing that it probably isn't the rear design, that would be hard to change!

Mike

 

[rhomodel]

As a matter of fact it would ruin the whole boat concept.......

 

[Don Templeton]

Hey Mike,

What about less AOA on the fronts? Just setting here thinking. :-

Don

By the way, what is your AOA?