Need input on .12 rigger ideas

[MikeP]

Don,

I have been checking the weights of different material. I think that the .064 CF is a bit thick and heavy, some of the guys here are using CF but really thin stuff .032 or less.

I have not used CF for a radio box cover, I have to be able to see in the box or I go crazy wondering whats going on inside.

I have never used anything but .032 lexan. The last ones I covered with transparent monocoat trim sheet. The monocoat protects the lexan from fuel and I can still see inside.

www.ad.kengarff.com/mikep/cf90/cover.jpg

-MikeP

 

[Hammerhead]

The last four riggers I have made have all had CF covers. I think that if you make your radio configuration bullet proof, you won't need to check it all the time. If you do get ants in your pants about it, what's a few inches of tape? Anything will work fine, but it's pretty hard to beat the attractivness of CF.

Hammer

 

[Trent Hare]

Hi Gents,

I hope this will help, or give you some ideas -

Here is some .12 rigger work I did back in 1994 or so.

I used an OS .12 CZR with 172 degrees of exhaust timing (155 was stock), 60% fuel, a MAC 2.5cc pipe and header, Octura 3" solid mount, Hughey hardware and a 1640 prop. It really flew, but the sponson ride surfaces needed to be about 3/8" wider on each side.

 

[TomMoorehouse]

we really need a .12 rigger website.... they are comming out of the wood work!

 

[MikeP]

I went back and found some talk about vee bottom riggers. The ones that were tested were 23deg. What I picture in my head is 23 deg instead of 26 will have a little more drag and lift but should be more stable. 26 will have less drag and lift, cut through rough water better but not as stable.

Using Propjockys formula I came up with the angles......... 24.5 deg.

-MikeP

 

[Don Templeton]

Unbelievable Trent!

Here I'm trying to get all the weight to the front of the boat and you stick everything next to the transom and it's fast! "I GIVE UP" :

Thanks for the pictures Trent.

Nice looking boat.

Don ;D

 

[Trent Hare]

Thanks Don,

I started with about 1 degree of strut angle when the motor was stock with 60%, but after the porting, even that was a bit much after it came up on the pipe. It would get a little hoppy down the back (rougher) straights. I ended up with almost a flat setup with the 1640.

...and having no rear sponsons didn't help either

 

[Hammerhead]

This is what I think is going on with the nitro levels in my .12. If I use 30%/ 18% oil, I can lean it out and it gets on the pipe immediately. If I go to 55%/20% oil with the same needle, I fry plugs. If I back of the needle to where it stops frying plugs, it won't get on the pipe. I can thought that maybe I could shorten the pipe, but it went back to frying plugs. I then tried lengthening it. No pipe action at all. I like the performance that I'm getting with the 30%. What do you guys think.

Hammer

 

[Ron Olson]

You might have to add a shim to the head for more clearance.

 

[Trent Hare]

I was running 2 head shims I believe, and McCoy #9 plugs with the 60%. The .12's and .15's I was running ran cooler, faster and idled much more reliably with high nitro. Once you get the head clearance right, and a good cold plug you should have much better results.

 

[MikeP]

Hammer,

Check your head clearance, find out where your at first.

-MikeP

 

[Ian Inverarity]

Hammer,

If you have access to the equipment, or a friend who can do it for you, then try increasing the bowl volume using a 2 flute ballnose cutter. Only take out a small amount at a time tho, espescially on an engine that small! It is better to try to maintain a tight head clearance so that the squish band works properly! ;D

Ian.

 

[MikeP]

Hey,

I found a injection molded composite rudder. The only reason I didn't buy it was the leading edge of the rudder is angled back. Does anybody know if that is a good or bad thing for a hydro?

-MikeP

 

[Ron Olson]

Mike, if you want to try an injection molded plastic rudder take a look at one made by DPI. It has a straight leading edge and a flat bottom on it which is supposed to help with lift on the back. A tapered leading edge, I don't know, how about it guys. ???

 

[Eric Perez]

Wouldn't that be like a built in rudder kickback? This will help lift the transom in the corners. I've seen Trent use rudders shaped like this on some of his hydros.

 

[MikeP]

I like the looks of the DPI rudder, it's looks light and is only $5.00. I could come up with a different mount for it.

http://www.dpileisuresports.com/prod-det.asp?prodid=37

Anybody seen a injection molded turn fin?

-MikeP

 

[Hammerhead]

What is the measurement on the rudder hinge shaft. That looks ultru light. Might be able to slap it right on my Hammerhead .12 with a little modification. If the holes are less than 4mm, than I could ream them out to fit right on my hinge.

Hammer

 

[Ron Olson]

The MRP boats have the rudder kickback feature. The DPI uses a plastic tapered pin that could easily be drilled out or tapped. I've got a Nitro Fury in my basement that has the rudder on it. DPI makes the Nitro Fury, it's a nitro version of the Shiada River Racer with basically a different deck. The only other probem you might encounter is the steering bracket might be a little weak and could be swapped out with an airplane control horn.

 

[TomMoorehouse]

huh... it might be worth buying one of those to check out

 

[Ron Olson]

I just went down and measured the rudder. The mount is 1" square and the hinge pin is out 7/8" from the mounting plate. The blade hangs down 3" below the mount. Think it might work? If anyone thinks it would work, I'll order a bunch of them and if I need to, I'll rip the one off the Nitro Fury. If you need the weight, I can take it to work and throw it on the digital scale there.