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 Post subject: Re: TI outboard mount
PostPosted: Sat Dec 16, 2017 2:13 am 
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Location: Delnor Wiggins, Fl Peters Twp PA
fusioneng wrote:
So the entire design was abandoned. Sold the boat, but some of the ideas and solutions are hopefully useful to others.
I'm not suggesting anyone do anything one way or another, I'm just sharing what worked out well for us.
Hope this helps
FE


You sold your boat, FE?


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 Post subject: Re: TI outboard mount
PostPosted: Sat Dec 16, 2017 10:33 am 
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Location: Sarasota,Key West FL
No, they all fit in one garbage can and went out to the road. There were about a dozen different props of varying experimental designs and pitches.

Kinda sucks because as a toolmaker, (from Chicago area), their are none of those types of business's down here at all so I don't have any access to CNC's or machine tools of any kind anymore. Everything was hand made freehand. That's why it was particularly painful when I lost that prop in the accident, the design part was easy, about 5-6 hrs to design in Solidworks or proe, but then actually making the darn thing was around 200-300 hrs of bench time each, (lol,,,stuff I used to cut with high speed CNC in two hrs). A Makino machining center runs around $500k, I won't be buying one anytime soon on social security, (lol). My Hydrofoils took well over a thousand hours to make.
I come from a long line of tool makers, my father, my fathers father, etc. As a master craftsmen in all the five trades my father gave me his cherished Moore tool box filled with all his tools ( which he got from his father), but I had to prove my skills to him with a test. He handed me a set of 3 rough cut 123 blocks, and a 6" angle block all roughed in. He said return these to me with all three of these equal, square, and parallel to within 50 millionths, and the angle block square all surfaces within 50 millionths, (a common term which is half a tenth, (normal gage tolerances are .00005"), he slid them across the table and I accepted the challenge. I happened to be top dog at the #1 shop at the time, they had everything imaginable machine wise in house, ( we had around 600 toolmakers) figuring I can do this in a few days, (simple stuff for tool makers with all the right modern equipment).
Then he said you don't understand, you have to do it the same way my father made me do it in the old days, your not allowed to use any machine tools of any kind or any modern technology, everything must be done by hand. It took me a whole dang year to get those things right, (workin at night, off hrs)
That tool box is now sitting in my garage full of my dads tools, lol,,, turned out to be full of really old junk that nobody uses anymore. Worked my whole career and never used any of those old obsolete tools, but I used those 123 blocks and the angle block daily. However over the last 25-30 yrs or so of workin I was the guy running those big global companies with hundreds of tool makers and engineers working for me, all over the world. Never once was I ever asked to go out and make anything on the bench, so I really enjoy designing and making my own crap, workin with my hands again as a hobby. And now I'm retired I got all the time in the world.
None of my three sons went into the trades, they all went straight thru to engineering school and have graduate degrees. I made the same offer to them, they looked at the tool box and all the old junk tools and said na, you can keep all that old junk, oh well.
You can probably tell from my responses, I'm now bored to death with nothin to do. Maybe I'll design and build another airplane or somethin, (maybe a float plane, or a personal flying machine), the design part is simple , ( thats what I do), it's the building part that's hard. I should probably drop off this forum.
FE


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 Post subject: Re: TI outboard mount
PostPosted: Thu Dec 21, 2017 1:34 pm 
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Heres what im thinking for an outboard mount. Not yet connected and length are not yet final. I'd like to first look at it for a few days before making the final cuts. I bought all these for 16 dollars from a metal scrap yard plus 4 dollars cutting fee based on my initial measurements. Uploaded as video to my Gopro. Im not yet familiar how to upload it as photos...

https://quik.gopro.com/v/1wvXs0uVvB/


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 Post subject: Re: TI outboard mount
PostPosted: Sat Dec 23, 2017 8:35 pm 
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Location: North carolina
Just fiished setting up dropbox account for storing pictures online.
So here's the pictures for better browsing experience.
Im showing here two possible locations for the mount thats why i have to keep the base longer lengthwise when setup close to rear hatch. i just received my suzuki. Will try and see how much more i nwwd to raise the mount.
https://www.dropbox.com/sh/rt1loadydx1t59p/AACCUCykLyxn16pyQn_77MUfa?dl=0


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 Post subject: Re: TI outboard mount
PostPosted: Sun Dec 24, 2017 1:06 am 
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Location: Delnor Wiggins, Fl Peters Twp PA
Fwiw I located my honda 2.3 just behind the rear seat on our TI. The downside is the noise (but I run pretty low most of the time) but the upside is that I can reach it easily. I have had to re-fuel while mid journey and also loosen the cap to compensate for a clogged air vent so that location has worked well.


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 Post subject: Re: TI outboard mount
PostPosted: Sun Dec 24, 2017 7:16 am 
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Location: Sarasota,Key West FL
Bobagain:
Yea we have the same issue with the gas filler cap air vents plugging up with our Honda's, (not a great design).
We also hate having to refuel while out on the water. I also really hate the noise and vibration of any outboard running at high rpm. Also as with most outboards, I'm pretty sure the fuel tanks are all sized to give the motor about 1 hr of operation at mid to high rpm operation.
In our case we refuse to run our engines at high rpm because we hate the noise and vibration, and the poor fuel economy. We only run the engines at high rpm's in dire emergency situations. We typically lock our throttles at just above idle when we pull out and leave the motors run all the time we are out, this gives us a couple-three hrs of runtime per tank, so we very seldom need to stop and refuel, ( I like that), also at very low rpm the motors are very quiet and we can easily talk over the noise.
I was at home depot the other day, (buying a mower), and saw they had aluminum big mouth screw on cap 1 qt reusable gas bottles prefilled with ethanol free gas for about six bucks. I thought it would be cool to make holders for a couple of those types of cans, and attach to my motor mount, verses what I do now,( currently we keep a 1gallon gas can in a cloth bag strapped down on the back of the boat), it's kind of a PIA to stop and have to refuel so we try to avoid that at all cost.
FE


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 Post subject: Re: TI outboard mount
PostPosted: Sun Dec 24, 2017 8:46 am 
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Location: Colorado
FE, your reality is often way different than mine. The only way I could get three hours of run time out of my setup is to travel at a much slower speed. It takes some HP to go a given speed - simple physics. There is some small efficiency difference generating this hp at different RPM but it is only a small difference. HP is torque x RPM. If the RPM is lower, torque has to go up. If the RPM is higher, torque will go down.

You can easily feel the relationship between torque and RPM on a bicycle. If you are pedaling up a hill at some speed, this will require some power. If you keep your speed constant (requiring constant power) and shift to a higher gear, you will pedal slower but its more difficult to pedal - you have to push harder. If you shift to a lower gear and your speed is kept constant, you will pedal faster but its easier to pedal.

Power at lower RPM or power at higher RPM is still power and requires close to the same about of gas. And you have to be careful with the higher torque by trying to generate a given hp at low RPM as it puts more stress on engine components. Going back the bicycle example, try going up a hill in a high gear. You have to really push hard on the pedals which puts higher stress on everything.


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 Post subject: Re: TI outboard mount
PostPosted: Mon Dec 25, 2017 11:37 am 
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Location: Sarasota,Key West FL
Walt:
You and I don't think alike, and never will. I was only describing I had similar problems with my gas cap, and also expressed how much I hate the motor noise, and never allow my motors to go over a certain rpm except in dire emergency. I also mentioned that I found 1 quart fuel containers that I thought would be useful.
Below pretty much describes what I was up against.
In this first old video, it shows the typical speeds my TI was capable of via pedal power and sailing in winds under 5 mph (which is 80% of the year around here). Peddling to the best of my ability, the boat goes 1.5 to 2 mph, (even with the sails out). Unfortunately the spot I was sailing that day is a good 4-5 miles from where I launch from. So getting from launch to that area at peddle speeds would take about 3 hrs most days. When that video was taken I had 260 sq ft of sail on the boat, but no point putting the spinnaker out as it just acts like a giant air brake in those conditions, your forward motion from peddling collapses the sail, and actually slows you down.
https://www.youtube.com/watch?v=zW62S1_RfYQ


In this old video from 2010 sometime. (taken the same day as the first video) I was power sailing with the outboard running, I think around 1/2 throttle, it's very loud and annoying, and not a fun experience for me. Basically the performance and noise were totally unacceptable to me.
https://www.youtube.com/watch?v=qiK_GM_U9pY


One major issue I have with the boat is the Honda's when cold, idle just fine and the clutches don't engage, however once the engines warm up the idle goes up and the clutches half engage, (you can see they are slipping, but intermittently when you look at them). As a result my minimum speed with one engine is around 5 mph, and about 7 mph with dual engines, this is with throttles all the way down at minimum. I actually need to usually kill one engine when coming in to shore, because I'm coming in way too hot. Of course it varies some days worse and sometimes better.
This is a video of me going thru canals with motors at idle, I don't recall if it was a good idle day or a bad idle day, and if I had to kill one motor or not. You should be able to judge speed pretty well, so you can judge for yourself the speed I was going, I think I was going around 5-6mph, which is pretty typical when I'm idling around ( I didn't measure my speed, why would I...). At this throttle setting (idle) I get around 3.5 hrs run time per tank of fuel. You can test this yourself by just starting your own outboard up in a bucket, and let it run at idle, then see how long it takes to run out of fuel, doesn't matter what brand of outboard you have.
Unfortunately I keep my gopro in a waterproof case, so the sound sucks, you can barely hear the motors running, but you can easily hear me talking over the engine noise, and there is no vibration from the engines.
https://www.youtube.com/watch?v=9jFCfBMZKKU


Keep in mind my stated design goal was to build a human powered tri-power propulsion boat based on the TI platform. This was stated 7 yrs ago, and everything I did and all inventions revolved around that goal, ( I'm an inventor). My stated goal was to build a tri powered boat that cruises 12-14 mph minimum cruise speed, in any and all conditions, (including no wind), and regardless of actual wind direction, (including almost directly upwind). The boat had to be able to go non stop 300 miles in under 24 hrs, completely self contained (no stopping for fuel). Fuel economy had to be better than 150 mpg with gas hybrid (or equivilent battery/solar/electric). The boat also had to be able to easily withstand offshore conditions up to around 25mph winds and 5 ft waves, (basically hardened for offshore). The boat also had to have emergency reserve power, to be able to get off the water in the event of a storm coming in while offshore, (my minimum 'get out of dodge' emergency reserve speed is 15 mph).
The entire design was a complete and utter failure and was abandoned, all the components were taken to the side of the road, and the boat was stripped and sold last month.
I ran into a kind of brick wall 3 yrs ago, (designwise), I only ever got to 10-12mph cruise in any conditions, including nearly straight upwind. my average fuel economy was 80 mpg (averaged out over three yrs), and my max non stop range was only 200 miles, (never got even remotely close the the 300 miles in under 24 hrs mark, so the design was abandoned).

Hopefully someone else will have better luck, I've moved on to other things.
FE
Edit: correction, in the last paragraph, I said 10-12mph average cruise speed, that average cruise speed is in favorable winds over 7mph, (actual natural wind direction isn't important), with no wind or very light wind the average cruise speed is 8-10 mph, (what the boat was designed around). Of course up wind is always the best point of sail, and broad reach is the worst point of sail on this boat. I'm not tryin to dictate how anyone use their outboards, (do what ever you like), I'm only describing how my TI has been used to provide tri-power propulsion over the last 3yrs or so. Averages are based on typical 15 mile weekly outings averaged over 3yrs (around 2200 miles). Averaged fuel economy is 80mpg, (obviously some days better and some days worse).

History:
In order to purchase my first TI in April 2010, I promised to pedal my boat an average 15 miles per week as my exercise program after having a heart attack, and show the wife my gps distance readings weekly, (actual fuel consumption was also measured). I held up my end of the deal faithfully. Obviously the previous 4yrs were much less stellar, (many really long exhausting weekends on the water,( lol), 15 miles makes for a really long day at 2mph), just sayin. My ultimate goal was always to complete the EC in class 6, (never got there, obviously everything ended up being an udder failure on my part).


Last edited by fusioneng on Wed Dec 27, 2017 6:34 am, edited 2 times in total.

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 Post subject: Re: TI outboard mount
PostPosted: Tue Dec 26, 2017 3:24 pm 
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Location: Central Coast NSW Australia
nap wrote:
Im showing here two possible locations for the mount thats why i have to keep the base longer lengthwise when setup close to rear hatch. i just received my suzuki. Will try and see how much more i nwwd to raise the mount.

I chose mounting the OB as far back as possible because:
1- less splashing in the rear well
2- quieter
3- still have storage space in the rear well.
As far as height goes, you don’t want too much OB under the water. It creates more drag and is more prone to hitting things. The bare minimum depth has advantages in that it can be used in very shallow water. You can steer easily in water that would be too shallow for the rudder by undoing the steering lock and using the OB as a tiller.


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 Post subject: Re: TI outboard mount
PostPosted: Tue Dec 26, 2017 5:18 pm 
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Yes Stringy. I saw your other posts describing your setup and thats what i want to test first. And will start with your mount height describednin that post.


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 Post subject: Re: TI outboard mount
PostPosted: Wed Dec 27, 2017 7:31 am 
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Forward or back.. trade offs. I like the weight of the outboard closer to the center of the hull and its easier to reach the controls (throttle, gear shift, pull start, raising and lowering). Down side of forward. you have to also build a splash guard to keep water off that back round hatch and its louder. In my opinion, the louder part is the big reason for moving it back and its a very good reason.

But.. the very shallow prop.. Hmm... The "lower drag" when the outboard is running? Have you measured any difference in speed? I bet that is in the noise. Running in very shallow water with the outboard.. asking to ruin props. I have never needed the shallow water motor running anywhere I have used the outboard. But... if you have a specific place/ application.. maybe.

Also, the water impeller pickup is just above the prop and the impeller will burn up very quickly if its not lubricated by water. You are more likely to suck air into the prop from the surface (ventilation) the closer the prop is to the water surface. The Suziki 2.5 also exhaust underwater and I know it gets louder when run in a bucket the closer to the surface the prop gets. There are a bunch of reasons I like the prop deeper.

My .02 What I think really does matter about the height of the outboard is splashing from waves. So you want the bottom of the mount raised off the gunwale and also the outboard mounting hardware that is likely to plash as high as possible.. but you want to keep the prop as deep as possible.


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 Post subject: Re: TI outboard mount
PostPosted: Wed Dec 27, 2017 9:00 am 
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Walt, for some reason any extra “plowing” that we can eliminate by raising the motor just seems like the right thing to do. I used to own inflatable boats that I would carry many different shims to put on top of the transom, to reduce the drag, according to the load. Probably not necessary, just all good fun. I would be VERY sorry at this point had I bought a long shaft motor, it would be dead idle only.

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 Post subject: Re: TI outboard mount
PostPosted: Wed Dec 27, 2017 10:09 am 
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Quote:
Probably not necessary


Did you ever measure any speed difference with prop depth? Or did it just feel like "plowing"? Small inflatables.. way different than an 18 foot trimaran where with the inflatable, your own body weight location makes a huge difference in speed.

Completely agree.. no need for anything but the short shaft on the TI. I personally just would not locate the prop too close to the water surface for all the reasons I mentioned (water impeller never getting starved of lubricating water, prop ventilation from air sucked in from the surface, louder exhaust noise). Short shaft is about perfect for the application.


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 Post subject: Re: TI outboard mount
PostPosted: Wed Dec 27, 2017 10:50 am 
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walt wrote:
Forward or back.. trade offs. I like the weight of the outboard closer to the center of the hull and its easier to reach the controls (throttle, gear shift, pull start, raising and lowering). Down side of forward. you have to also build a splash guard to keep water off that back round hatch and its louder. In my opinion, the louder part is the big reason for moving it back and its a very good reason.

But.. the very shallow prop.. Hmm... The "lower drag" when the outboard is running? Have you measured any difference in speed? I bet that is in the noise. Running in very shallow water with the outboard.. asking to ruin props. I have never needed the shallow water motor running anywhere I have used the outboard. But... if you have a specific place/ application.. maybe.

Also, the water impeller pickup is just above the prop and the impeller will burn up very quickly if its not lubricated by water. You are more likely to suck air into the prop from the surface (ventilation) the closer the prop is to the water surface. The Suziki 2.5 also exhaust underwater and I know it gets louder when run in a bucket the closer to the surface the prop gets. There are a bunch of reasons I like the prop deeper.

My .02 What I think really does matter about the height of the outboard is splashing from waves. So you want the bottom of the mount raised off the gunwale and also the outboard mounting hardware that is likely to plash as high as possible.. but you want to keep the prop as deep as possible.


Everything you mentioned were the reasons why I'd like to test that forward location before trimming the excess length of my OB mount.
I had TI before with Honda sitting right behind me (sold) and never remembered I hated the noise. Maybe because my ears are clogged or not as excellent as Stringy's hearing ability (LOL).

https://quik.gopro.com/v/1wvXs0uVvB/

And as per my OB mount, I will have to drill holes to reduce the weight. It's currently 12 lbs.


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 Post subject: Re: TI outboard mount
PostPosted: Wed Dec 27, 2017 11:27 am 
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I'm not sure if this will help or not when determining prop depth, motor position, etc. The motors in this old video (2014) are stock short shaft Honda 2.3's, with the only change/mod from stock being custom higher pitch props. The motors were mounted as close to the hull as possible, and tilted around 5 degrees so the props were partially under the hull. You should be able to judge the mounting heights and speeds via comparison to your own experience, most of our boats are all exactly the same. The motors were very quiet at low rpm with their underwater exhaust, (I typically never ran over 1/4 throttle because I hated the noise).
When I beached I typically didn't tilt the motors up. In other words around here anyway with the bow touching shore, the bottoms of the props don't touch the bottom, (if that means anything). I typically beached with the engines running.
I never had any problems with air sucking into the props on tacks (which you can easily hear).
In this video the hull is planing, (the hull is slightly modified). The indicator of planing is the cresting wave 2-3 ft behind the boat, as the boat speeds up more, the wave moves further away behind the boat.
https://www.youtube.com/watch?v=tR9oJL6psds


Hope this helps
FE


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