Shovelnose Hydro

[rich zella]

I have succesfully built from plans by Garry Finlay a shovelnose hydro that was originally intended for electric power. With a few beef ups to the stringers, I am going to run a .15os marine engine in it. Homemade hardware, 4 oz. fuel tank, and probably no cowling as I am no artist. I just tried to balance the cg of the hull 1.5 in. behind the sponsons, but find will have to add8 oz. of wt. to the nose to do it. ??? Is this normal to add this much wt to baalance a hull ??? Help

 

[Propjockey]

Rich -- try to get the balance as close as possible by re-arranging the 'guts'. Use what you've got before adding additional weight. 8 oz. is a fair amount of weight for a hull that small (I'm assuming less than 30"), but remember...8 oz. heavier with the right CG will run better than 8 oz. lighter with the the wrong CG.

Got pics?

 

[rich zella]

;D,Tnx, I hope this thing runs good and is fast

 

[Don Templeton]

Rich,

Where did you get that 1.5" dimension? Just asking because I'm not familiar with a shovelnose set up and if you got that from our .12 rigger conversations it might be a whole different animal. ???

 

[[email protected]]

A trick we use in 1/8 scale is to put the strut on a small scale. Than keep adding weight to the nose until the scale reads one pound. That's when you hit the mark. I wish I knew the idle weight for such a small boat so I could help you.

 

[forresterace]

Hi Guys

A general rule of thumb for balancing 3 point hydros is to place the CG at about 15% of the afterplane (distance from the sponson step to the transom) back from the step. With a high lift shovelnose, however, this can be reduced to as little as 10%.

It has been my observation that the .12 to .15 motors work best in a 3 point hull that is around 24" to 26" long.

I hope this helps.

 

[eddieh]

Doug good tip, I am in the process of building one as well, (sorry guys electric) unless I can get the miniature allison going lol here's apic

 

[TomMoorehouse]

wow eddie.... looks like a real show piece! like it should be on a display stand!

 

[rich zella]

Great job eddieh. Did you build from plans or a laser cut kit. Mine is straught off the plans. Mine should look so good. I'm not the pro u are. How did u build you're cowling aaand engine?

 

[eddieh]

Rich, the hull was a kit, I added the mahogony, the cowl is balsa carved and then hollowed out, the antennae is mounted in the fin, the engine is scratchbuilt the block and heads are balsa covered in abs, the valve covers, blower zoomies are made from aluminum, I brazed the aluminum zoomies onto a manifold, this technique might have applications for you guys, the product is called alumiweld, and works with a propane torch, I use mapp gas as it hetas it up a little quicker, I will make the hardware.

thanx for the kind words, cheers eddie