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PostPosted: Tue May 06, 2014 7:25 pm 
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fusioneng wrote:
Tony your being a little harsh on the guy, but it is good advice for all of us.
Jeffery just happened to already have a very rare and hard to find old 2 stroke Johnson, those motors are famous for their reliability and light weight. There actually quite a few guys that have 2.5 and 3.5 hp Mercury and Suzuki 4 strokes on both AI's an TI's. As you know modern motors are a lot heavier than those old two strokes. At least over here you cannot buy a two stroke anymore which is a shame in my eyes.
Bob


Hey thanks Bob :D I tried to post a pic of my setup but cant figure out how you posted pics without linking to an external website. I hope you can post pics soon of how you managed to setup yours up to sit higher out of the water under power.


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PostPosted: Tue May 06, 2014 7:53 pm 
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Sorry, I didn't mean to offend anyone.

As for the stern dropping, this is a fundamental aspect of displacement hulls. As they go faster the length of the bow wave grows, until at maximum displacement speed, the stern sits right at the bottom of the wave (you can see this when you look behind and see the rest of the wave getting higher0 effectively causing the vessel to be "travelling uphill". Adding a planing surface (as both you and Bob have mentioned) can make a difference, although the amount of power needed to break out of displacement mode is not trivial.

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2012 Tandem Island "SIC EM"
www.scenefromabove.com.au


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PostPosted: Thu May 08, 2014 10:35 pm 
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Location: Sarasota,Key West FL
Well I was able to get out today and do a second test on my twin Honda 2.3 engines. I have to say this has worked out way beyond any of my expectations and I am tickled that everything actually works. Actually beyond my wildest dreams.
I replaced the 10 inch pitch propellers with the same 7 inch pitch propellers I've been using for the last 4 yrs, and boy what a difference that makes. The ten in pitch props were just too much for these little 2.3 hp motors. I haven't double checked the fuel economy yet, but after measuring my fuel usage today, I'm thinking my fuel economy will remain close to what I was getting with the single engine, with duel engines (around 75-100 mpg).

I started out today with no sails up and pulled away with the motors running just above idle, the boat was going 5-6 mph (If you recall with the single engine the boat would go 3-4 at that throttle setting).
I opened the throttles up to just below 1/4 throttle (just below the normal setting I have always used) and instead of 4-5 mph the boat was traveling 6-7 mph (without sails). As soon as I opened up the wing and main sails the boat took off in around 7 mph winds I was quickly doing 8-9 mph ( used to be 6-7 with the single engine), actually I'm pretty sure the dual engine setup can operate efficiently at a lower throttle setting as compared to the single engine setup, and the resultant speed is much higher.

Basically everything I described (in theory) has worked out in reality, and I really feel I have a setup that I can really use. The only problems now are:

1. I can no longer smoke while underway because I cannot get the cigarettes lit with my lighter (true story today)

2. I have to now get a new sailing hat because the bill on the hat flies up, this never happened before today.

3. My spray skirts were useless today, I made them a year or two ago from heavy duty patio screen material, and never had any spray problem before, the spray went right thru them and I got pretty wet. With the natural wind 7-8mph plus the forward motion (9-10mph) the wind on my face was about 18mph (breezy), the water coming thru the screen shot right back at me.

4. I now need to plug all the scupper holes and mirage drive holes as the water squirts up thru them about a foot like a geyser now (never had any problems before), in the video you can see the water geyser in the rear mirage drive opening (would be directed at rear passengers face and chest, (note to self, must fix before taking wife out, or she will never trust me again).

5. I will have to pull the mirage drive because it was fluttering quite badly today if I stopped pedaling in the water (may get damaged), never noticed that before either. (Note ( I still pedal most of the time up to around 10 mph, I think above that speed I need to pull the mirage drive). But then again I have no reason whatsoever to go faster than about 10 mph, I'm fine and very happy with continuing to pedal the boat.

At the very low throttle setting that I use (typically less than 1/4 throttle), the engines are very quiet, you can easily talk over them, definitely not annoying at all. The sound from twin engines running is totally unique and distinctive (cool factor 10 plus).

I have the urethane foam on order to re-shape the rear of the TI hull (get rid of the point), and will have that mod done within a week or so, I expect my speeds to increase quite a bit once I get the hull planning, and eliminate the huge wake at the back of the boat (as seen in the video below).

Because of the lift created by the wing, and the weight of the extra motor (27 lbs) the bow and AMA fronts now ride continuously 3-5 inches out of the water which is perfect (in order to plane the bow front will need to be completely out of the water. (planing on the big flat bottom of the boat)

[youtube]http://youtu.be/jO1uuzBLBec[/youtube]
https://www.youtube.com/watch?v=jO1uuzB ... e=youtu.be

Here is a pic of both the 7 inch pitch prop and the ten inch prop side by side:
Image
The 10 inch pitch prop even after reducing the dia down to 7 inches is still too much for the motors (the clutches worked fine, but I could get any rpms out of the motors), I'll put those props away for now, and only try them after replacing the main sail with a rigid wing sail (phase 3).

In the video if you look at my pirate flag on the mast you can see I am sailing almost directly into the wind (about 15 degrees off the wind) at around 9-10 mph (the wind was around 7-8 mph at the time).

I can't wait to do further testing, and get that hull re-designed.
Bob


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PostPosted: Sun May 11, 2014 8:02 am 
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By this time next week I will be another step closer to phase III of my development (a 30-40mph hybrid TI with hydrofoils and full wing sails), obviously I'm still at least a year or two from completion, but am total confident now that it wall all indeed work beyond even my wildest expectations.
If you look at my twin engine shake down video above (first sea trial with the twin engines (always want to say that)), you will notice that the front of the boat is way up in the air (what I was trying to do), however the back of the boat had huge turbulence and was squatted and sunk in the water way too much (not a planing hull situation). As a former hydroplane racer, I used to design and build 3 point hydroplanes (designed and built several) so with the TI my plan is to simulate the same effect (eventually) as the way 3 point hydroplanes work, basically two ski's on the front (my existing hydrofoils) and a flat bottom 3rd point in the rear capable of planing. Actually because my wing create so much lift to the bow, instead of full blow hydrofoils on phase III I may opt for flat bottom tear drop shapes on the rear 1/3 of the AMA's, about 8 inches wide at the widest point (foam and fiberglass (I bought enough foam and fiberglass to do this as well). With this setup the 3point planing at speed would occur on the rear 1/3 of the boat and the back tip of the AMA's, this would eliminate all the downsides of the hydrofoils (double drag), and I may not need them at all (we're talking about planing AMA's just like on Randy Smythes famous Sizzors tri, way cool).
It helps that the foam core transom add around 100 lbs of flotation to the back of the boat as well. If you watch the above video you can see I already have the correct stance for the boat at speed, the bow and fronts of the AMA's are nearly always completely out of the water (created by the lift created by the tilted wing in front of the boat), the only downside currently is the rear of the boat is sunk 6 inches too deep (creating a lot of drag).

Here are some pics of my progress on the new planing type hull, I still have to finish and gelcoat (which is the biggest part of the job).

First I had to outline the finished shape with a template mold, I just use card board because it's easy to cut and form, and better yet it's free.
Image

Next step build side walls for the mold so the foam doesn't just spill out on the floor, the walls are re-enforced with cardboard to prevent them from bowing out as the foam expands.
Image

Finished mold ready for the fiberglass cloth (inside layer)
Image

Inside is all glassed and ready for foam ( I spray painted over the first top of the first clear gelcoat layer yellow to give the inside some color, then glassed over it.
Image

Here is a pic after the first batch of foam (24 oz of 4 lb 2 part urethane foam), notice the little strings of para-cord, those are used to strap the removable back end to the boat.
Image

Here is the finished new rear end almost ready for gelcoat ( I estimate it will weigh 6 or 7 lbs)
Image

Unfortunately I have to travel to Houston for a week (on Business) leaving today, so it will be a couple weeks before I can get back to it.
I can't wait to finish it up and see what it will do.

Obviously the thing is only needed for high speed offshore sailing and would be removed the rest of the time, it just takes 30 seconds to strap it onto the boat.
Disclaimer ( No tandem Islands were injured making this )
Bob


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PostPosted: Sun May 11, 2014 8:29 am 
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And this from the guy who said, "The Tandem is perfect just the way it is," or something to that effect.

Wow, quite a project, Bob!

Keith

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PostPosted: Sun May 11, 2014 11:40 am 
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Location: Sarasota,Key West FL
Yea Keith I called the hypocritic oat ( make no changes to the boat itself, lol just like doctors. I still live by that rule, everything I have is removable addons and whenever I get a new boat I just transfer it all to the new boat.
My problem is I'm an inventor, I sit at the computer 60 hrs a week designing new things (kinda boring).
I spent 30 yrs on the bench as a master craftsman ( haven't actually worked on the bench in over 20 yrs though after going into management.
I like to work with my hands so the biggest part of any of my Hobies is making all this stuff in my garage. You can't fault me for liking to mess around and have fun.
Bob


Last edited by fusioneng on Sat May 17, 2014 6:55 pm, edited 1 time in total.

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PostPosted: Sun May 11, 2014 1:13 pm 
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fusioneng wrote:
You can't fault me for liking to mess around and have fun.
Bob


Bob I'm sure everyone here applauds you for your creative solutions, and entertaining antics! :lol:

Your motto might be, "Go boldly ....where no kayak has ever gone before!"


Last edited by proyak on Sun May 11, 2014 3:08 pm, edited 1 time in total.

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PostPosted: Sun May 11, 2014 2:28 pm 
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Heck, Bob never lets reality slow him down! :lol:

And we love watching mad scientists at work. That's why his thread is over 40,000 hits now.

Just wait till he puts the foils on this thing,.. :mrgreen:


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PostPosted: Thu May 15, 2014 10:14 am 
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My wife hates you, btw :mrgreen: But I was smart enough to take off all this bowsprit shenanigans you're forcing me to do when we went sailing together last weekend. That is to say you were smart enough to make it removable.


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PostPosted: Sat May 17, 2014 7:05 pm 
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DM06:
Yea everything is removable, that's what so cool about the TI, you can rig it for pretty much anything and it seems to do pretty well, most guys I see have their TI's tricked out in some way or another to suit what they like to do which I think is a pretty nice ability.
We are going to Camp Wilderness at Disney next week for a couple weeks, and I asked my wife if she wanted me to bring the boat, 'her answer was (censored)'.
We are planning to go the first few days to some springs just north of Disney, and she said she thought it would be nice if we took the TI (as a kayak, without all my junk) and car top it, but we will have quite a few people so we will likely just rent kayaks once we get there.
Bob


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PostPosted: Sat May 17, 2014 7:31 pm 
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Well I got back from my business trip to Houston, and finished up my planing hull attachment Friday nite and went out today.
It did everything I was expecting I was able to get up about 12 mph today, I would say my average was around 8-10mph (with engines running at 1/4 throttle). Next time out I will take video, the rear of the boat now rides very high in the water (about even with the roto-mold parting line on the boat, which is exactly where I wanted it to be. Without the new back end the entire rudder was under water (around 6 inches deeper in the water) when I'm powersailing and I noticed a huge wake behind the boat in previous videos. Now the water parts nicely behind the boat just like a powerboat would when planing.
Of course with the engines on the sides instead of behind the boat there is still some turbulence from the lower units, but I don't think I will ever get rid of that.
The bow and the fronts of the AMA's still rise out of the water completely (because of the lift created by the angled wing sail).
I believe I successfully converted my hull into a planing type hull (woowoo)

Once I get the new motor broken in (have to run 10 hrs at below 1/4 throttle to break the motor in) I may open it up to see what it will really do, just for fun, running at full throttle defeats everything I'm trying to do though ( I already know the boat goes 11-12 mph at full throttle with no sails out ( on flat water and little wind) with the old hull configuration, and 7 inch pitch propellers). It topped out at 9mph with the single engine with no sails on flat water.
Once I get everything dialed in hopefully I should be able to make gopro video with the hull in action at speed with the hull actually planing.
Bob


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PostPosted: Sun May 18, 2014 3:32 am 
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Bob, as a former Shipwright and presently an Aerospace technician, I'm enjoying the heck out of your postings.
It's great to see what some may consider figments of imagination turn into manifestations of proof of concept with a pioneering spirit.
May God speed your initiatives and thanks for sharing what some people may call madness with the rest of us restless spirits who may have landlocked minds.

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PostPosted: Thu May 22, 2014 9:01 pm 
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It was a beautiful day for sailing today so I thought we would go out, my daughter is down for a couple weeks so she came along. The water was nice and flat and the winds were around 6 mph today and the temp outside was around 85 ( a perfect day).

I finally solved the turbulence problem caused by my motors and the back of the boat. I studied the lower unit and realized that these lower units are designed to go behind the transom of a boat, so from the cavitation plate up to the motor, they don't do anything as far as hydrodynamics (it's just round).
I god some aluminum and foam and made up quick wings that mount over the round part of the shaft (they only took a couple hrs to make, really simple)
Here is a pic of one:
Image

With the addition of those and the planing hull mod to the back of the boat I am happy to say there is virtually no turbulence back there any longer.
Here is a snap shot of the boat doing between 8 and 9 mph today notice no big wake, and the rear of the boat is 6 inches higher in the water over previous videos:
Image

Here is a short video of us sailing most of the time we were traveling 7-8mph (in 6mph winds), we were out about 2 hrs and I measured our fuel consumption when we got home and we used $.52 cents worth of gas. Top speed for the day was around 10 mph. With my daughter way forward on the tramps the bow wasn't up in the air like it normally is when I'm alone sailing from the front seat. When she sat in the back seat everything worked quite nicely (the bow was out of the water, and the boat seemed to be planing properly)
[youtube]http://youtu.be/HjJ-9rvDOi8[/youtube]
http://youtu.be/HjJ-9rvDOi8

All in all I'm quite happy with these latest mods, and I will probably keep them.

Bob


Last edited by fusioneng on Fri May 23, 2014 7:18 am, edited 1 time in total.

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PostPosted: Fri May 23, 2014 1:00 am 
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That wake looks sensationally smoother Bob! It is difficult to even realise that back there are two outboard legs plus the rear of a (normally) displacement hull. I can hardly wait until you get the chance to let 'er rip in stronger winds!

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www.scenefromabove.com.au


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PostPosted: Fri May 23, 2014 5:02 am 
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Brilliant Bob

we have yet to have the weather to get ours out to try the Jib.

Can you post a picture of the finished "smooth bottom" at some point


cheers
trevor

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