.12 hammerhead (project speed)

[_laxmasta2039]

well duh, it's your boat!! ;D

i kinda want to take back what i said now, im afraid hearing how fast yours is going will give me expectations that are way too high!!

joe

 

[Hammerhead]

Hehehe! Remember Lax! This is my first attempt at a .12. We'll just have to see how it goes. Race on buddy!

Hammer

 

[Don Templeton]

Hello Hammer,

I hate to be a pest but I'm back at the drawing board trying to figure

out the rear end of a rigger.

Assuming that your tub bottom is flat with no air dump, you'r using a

V-937 prop and your 11mm rear sponson depth was measured from

the actual tub bottom and not the piece of wood between the rears.

With what you have told me before, I am guessing you will set the

bottom of the strut barrel at about 9.5mm below the tub bottom and

at 0 degrees to start with.

What this all adds up to, in my "little" mind, is that you figure that at speed, the running surface of the water will be at approx 50% of the

blade length measured from the outside of the hub to the tip and

that this would allow the boat to run at a level attitude.

Is my thinking anywhere in the ball park or am I still all messed up? ???

Thanks again and have a Merry Christmas,

Don

P.S. I took your suggestion and reworked my rears to a little over

2 degrees instead of 6. "MUCH BETTER" It will be some time before

testing though- got 6" of snow last night.

 

[Hammerhead]

Well Don, to tell you the truth, I will be running the stuffing tubes level with the bottom of the rear sponsons. Not at centered to them.

You are right. There is a 2mm thick board running down the center of my rears, so there is actually only 9mm of clearance. My stuffing tube is 6mm with 5mm teflon, and a 4mm flex cable. So take the 6mm diameter for an overall and subtract it from 9. This will leave me 3mm of clearance between the board running between the sponsons and the top of the stuffing tube. I will run it level for starters, but I always end up dumping the the strut down about a millimeter or two and angling it at about 1 degrees. I didn't do any calculations to come up with this set up. I copied the set up on my friends .15 rigger. It think the .12 I have will be more powerful than his antique CZ, though. He is running a x438, and going about 35 mph. His boat weighs a lot more than mine does, as well. Hmmm. If it doesn't work, I have a ton of wood left. I can always whip up another one.

If it is snowing, you should get an airboat. My older son is looking forward to a blanket of white, but nothing so far. He has a K&S Pacer .32. It runs better on snow than it does on water.

Hammer (Merry Christmas to you, too.)

 

[Don Templeton]

Hammer:

Thanks again for the input. I think if I just raise the rear of the strut

about 1/16" and set it at one degree I will be happy with the set

up and ready to test when it warms up. For now, it's back to the drawing board with some new ideas which is one of the most

fun parts for me.

I had a Dumas swamp buggy years ago and you'r right, thier great

on snow.

Don

 

[Hammerhead]

Here are some more pics. The First one is of the motor mount. It is extremely light. You can see from this shot that a lot of useless weight has been drilled out.

 

[Hammerhead]

This next pic shows its size compared with a standard ball pen.

 

[Hammerhead]

This next pic is of the power plant. For those who don't know, it is a 5 port, turbo head .12TR-P(T) . This version is only available with a pilot shaft, but as you can see by this picture, I have taken care of that problem. It has a CZ.15 flywheel, and an Octura flex shaft coupler on it. It has been tuned, but I ordered it tuned, so I don't know what exactly has been done to it.

Tom! If you are out there, could you give me an idea what a good pipe length is for this baby.

Hammer

 

[Don Templeton]

Where do you come up with these parts? ???

Hammer, I've been thinking about the Rossi Black Pixi .12 for my

next project and it only comes with the pilot shaft. The OS flywheels

that Tom and I have on our TRs with regular shafts are not the

same as yours. They just have a 5mm lole through them and fit up

against a drive washer. Does yours have a brass collet or a drive

washer behind it? Also ours our chrome plated brass and yours looks like aluminum. Not only that, but my Octura .150 flex coupler doesn't

look anything like yours. Did you have to cut off the pilot shaft or

anything. I can not find a 15CZ flywheel anywhere!

Don

P.S. The motor mount looks really great. You've gone all out on this one!

 

[Hammerhead]

Hey Don! There is a hobby company over here called ABC Models. They have an original RTR mono called the Dolphin. It comes with a CZ that is water cooled. This 100% aluminum flywheel is a spare part for that RTR.

The shaft on the TR-P(T) is 7mm, not 5mm. It has really big threads on it, too. this is the only mount that I could find, that would fit. Its collet it 4mm. That is a pretty big reduction.

I had originally planned to have the pilot shaft replaced with the normal TR crank shaft, but it was a lot cheaper just to wack the rod that trails the threads off, so that is what I had Mr. Shimizu do. The flywheel didn't have to be machined to fit, either. The flywheel has a black anodized steel cone between it and shaft.

I haven't tighted it down, yet, so I will pull it off and take a picture later. Is this cone what you describe as a drive washer?

The motor mount isn't finished yet. I have to make 2mm carbon washers to go between the rubber mounts and the tub walls. I won't make a set of outer rails. The mount bolts will go straight through the tub and carbon washers and into the female ends of the rubber mounts.

Hammer

 

[Don Templeton]

The drive washer I am talking about is this thing that slides on the

shaft in front of the bearing to keep a prop or flywheel from running

against the housing or outer bearing race.

 

[Don Templeton]

Our flywheels just press up against the drive washer and tighten

down with the flex coupler. The collet I was refering to is what

you are calling a CONE.-"Much better description."

Now, what are "you" calling the collet?

This is the flywheel that tom and I are using on our regular 5mm shafts.

 

[Don Templeton]

This is the Rossi Pixi I am talking about. Looks like it has some sort

of a cone on it.

Well, I just realized I'm cluttering up your great thread with a lot

of irrevelant stuff. This is my last post that does not pertain to your

rigger. Sorry! I'll delete these after you have a chance to look.

Don

 

[TomMoorehouse]

from what i can tell the rossi pixi is $325!!! thats a little overboard for a .12 for me..... as cool as it is I ain't paying that much for a .12!

now if you go to http://nitrohouse.com/nova_rossi.htm they are selling the nova rossi's for $149! now that is a good deal!

 

[Don Templeton]

Hello Tom,

I just new you'd show up. ;D

These are selling at Tower Hobbies for 219.95.

Look under Trinity Engines and check out the specs on this baby!

Also you can check them out at team Trinity.

Then let me know what you think!

(Wow) I just noticed I got another Star for Christmas. Goes

real good with my new picture! 8)

Don

 

[TomMoorehouse]

well that is better on the price..... and it looks cool..... but you think it really could beat a nova rossi??? does any body know abut these??

 

[Don Templeton]

Tom I really don't know but the specs on that engine sure look good.

Did you read the specs on it at tower? I haven't heard any comments

about it from anyone.

Talk to ya later. Gotta get my beauty sleep!

Don

 

[Hammerhead]

Hey Don! The input you are giving to this thread is worth a lot. Even if it doesn't have to do with the Hammerhead.12; it does deal with .12 riggers. This is not just a show case for my boat. It is a vault of info for anyone that is interested in trying .12 riggers. DON'T DELETE anything.

The set up I'm using is similar to the Pixi. I will take mine apart and post some pics. As for the price, I think I have dumped about 220 dollars into this engine with the mods and machining I had done to it. Also having to buy another carb bumped it up a bit.

Hammer

 

[Hammerhead]

The cone (or collet) is stuck in the flywheel. I couldn't get it out, so it looks like it is there to stay. You can see it in the back view of the fly wheel. It is black anodized steel.

 

[Hammerhead]

One more angle!

Hammer