Spirit of Australia

[785boats]

Hi Fluid.
The Total area of the inlets is 6926 sq mm
The SFA & thrust tube outlet area is 5138 sq mm.
The total area of the 90mm fan is 6358 sq mm.

So the inlet area is nearly 24% larger than the SFA

If I had made the inlets to scale, the total inlet area would only have been 4752 sq mm.
I hope it can suck enough air in to get the thing running.

[boredom.is.me]

Just remember to keep it smooth

[785boats]

You betcha buddy.
I'm working on that now.
All of the foam has been removed & I'm working on the curved inlet lips as we speak. I mean 'type'.
then I'll lay another bit of glass cloth around the inside of the inlets, & paint the whole inside with resin up to the fan.

[boredom.is.me]

A bit late to wonder/mention/ask, but have you ever thought of dissolving the foam with a solvent? Maybe acetone or something? The feasability and effectiveness of that method is just something I've always wondered about.

Almost there though. I can't wait to see this thing go.

[785boats]

That was my first thought too. But Acetone didn't even look at it. The foam blocks are high density polyurethane I tried laquer thinners too. Nothing.

The rudder arrived yesterday so now I can install the pushrod through the transom in the right spot & then cover the last of the cowling frames, & add the tail section. Then it will look like the real thing.
But it's our last day of racing for the year tomorrow, so I've got 4 boats to prep for 4 different classes tonight.
And some new batteries to cycle a couple of times.

Here's the finished cowl with the rounded lips.
Just a bit more sanding & smoothing, then a coat of resin to finish it off.

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[TheShaddix]

I've been reading up on these boats. Very inspiring to say the least. The guy had no money yet managed to somehow achieve speeds that no one can beat to this day. I can see where you get the drive to do all this work and recreate these legendary boats. Some day you might want to get an actual jet turbine and build one of these in a slightly larger scale.

[785boats]

There are some inspiring & tragic stories in the pursuit of the water speed record. But I'm not brave enough to try this. Or rich enough.
I doubt that you can get an airforce surplus jet engine for $69.00 any more.
But speaking of "Pursuit", check this latest effort from a British team to win the title back. The Pursuit 350. What a drop dead gorgeous rigger. I'd like to make one as an ordinary prop rider to race.

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[TheShaddix]

Oh, I was talking about building an RC boat with a jet engine (jetcat turbine), a bit larger in size than what you're building now. Can't seem to find that boat you mentioned.

[785boats]

Sorry.
I thought you were referring to a full size effort
Here's a bit of info on the Pursuit 350 project.

http://www.britishpursuit.com/

[NativePaul]

Haha 350, or OSE? Steven needs to change his font to take advantage of all the free advertising when this starts making passes.

[Fluid]

So many flashy designs, so much hype, so many sponsors, so much BS...

[NativePaul]

LOL at the big black one, Cobb died in a rear sponson canard, Campbell died in a forward sponson hydro, I will make a mid sponson hydro and live forever!

[785boats]

Fluid.
It's true, there have been many projects started & just haven't come to fruition. Usually through lack of sponsorship money. It's always about the money.

Paul.
John Cobbs' Crusader is the next one I will be building after this one. Yes it killed him. But I just love the look of the thing. And you know I love canards. So it's compulsory enjoyment for me.

For those that aren't familiar with the boat.

https://www.google.com.au/search?q=J...phBAQQ_AUIBigB

[Fluid]

Back to R/C boats: this reminds me of the chase for the fastest R/C boat. Set high by Joerg years ago, many tried to even match it. Lots of claims, LOTS of $$$, and finally someone beat it by a couple mph. Only then was Joerg compelled to defend his record. We all know how that turned out.....

I really want this build to succeed. I doubt it will be nearly as fast as a conventionally-driven boat of this size or power, but that isn't the point. This is about recreating a classic WSR boat down to the air-driven propulsion. Get busy and put it on the water!


.

[785boats]

Thanks Fluid.
I'm going as fast as I can. No one wants to see it work as much as I do.
For sure I'd be surprised if it aproached the speed of a prop driven boat. But as you say, it is all about replicating the original as closely as possible. I'm certainly not after any records.
If the fan gets fully loaded up, the calcs say that it will be pulling about 3600 watts. We'll see.
That old saying comes to mind. "Hope for the best. Prepare for the worst".

Well. I'm heading off to the lake now, for our last day of racing for the year. I'm contesting 4 classes today. The pressure's on! Ha! Ha!