Collapsible Flettner Rotor Project

Discussion in 'Projects & Proposals' started by Yobarnacle, Jun 4, 2014.

  1. Sailor Alan
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    Sailor Alan Senior Member

    Lateen sails.

    Thank you for the much clearer explanation, I'm sure i understand the differences now. I haven't personally seen one so tacked, but then i do not think i have ever seen a real lateen tacked at all, merely sailing, and slowly at that.

    There is no doubt in my mind that lateen sails were, and indeed still are, flown with the yard horizontal, at right angles to the hull centerline, for direct down wind sailing. I've seen them in person on the Nile. i think all the ‘modern’ lateen sails i have seen propose reefing down one of the ‘legs’ and not on the base. Most, if not all diagrams, and including, i think, Tim Severin's book, “the Sinbad Voyage” also include the concept of bringing the forward bottom, the ‘tack’ if you will, back to the mast base for tacking. Now, not only does this look difficult, not to mention fairly dangerous in a seaway, but in many cases the forward part of the lateen yard is too long to fit, i.e. its longer than the height f the mast. All this is a case for Lateens to be ‘tacked’ by swinging the spar back and around the mast, unlike Yobarnicale’s supposition that lateens were ‘tacked’ by rocking the spar ‘seesaw’ fashion over the mast. Perhaps both techniques are practiced, different tribes for instance? My question would be, could that very serious block and tackle used to hoist the spar handle the twisting strain of such a movement, and how do we resolve the multiple photos of lateen rigs where the lateen spar is obviously rigged with far more spar to the rear than forward.

    Yobarnical, rigging your particular Lateen rig to tack either over the top, seesaw fashion, or between the legs of an “A” frame mast sounds promising. Either should work OK too. Im starting to worry about serious overload for your boat, 2+ rigs, Fletner tower, diesel and electric drive, perhaps a parasail for fun, and now a electric air propeller for really calm days. I didn't notice a Yolh or sweep yet, but they must be there somewhere. Perhaps galley oars too?

    There is no doubt the lateen rig was faster, on all points of sail except perhaps dead down wind, but Christopher Columbus at least was embarrassed by the speed of the Nina, and possibly the consequent cocky attitude of its captain, and so it was rejigged with a square sail on the front two masts (or so i believe). At least they were all smart enough to carry a Lateen on their mizzen masts, for maneuvering, and balance at least.

    i for one appreciate the ancients use of technology. Some years ago i discovered a very special woven tape that had NO stretch in the linear direction. It was originally made to edge (windward edge) the square sails of HM warships, allowing them to sail several points closer to the wind than any other nation (including America). This ability certainly won battles, if not wars, and was a military secrete, ITAR for the ancients. At the time of the American ‘war of insurrection’ or ‘war of independence’ as they like to term it, this WAS a military secrete of some importance. By the time Britain and America were friends again, steam navies were in vogue, so the technique never crossed the atlantic. No university in America knows about it to this day. Mind you precious few universities know about it anywhere else too, the internet wasn't started back then. I was able to resurrect this technique, using modern materials like carbon fiber, and now it is standard practice on Boeing carbon fiber airframes at least.
     
  2. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Thanks for the tape story. I have often felt there is much the ancients knew that was lost or perverted since. The unbalanced lateens on native craft of today. A case of improvement that destroyed some functionality? Who knows.
    IntrepiDos, the first of my Albins, is foremost a comfortable live aboard for two, for a few months each year. A marina boat. That is my main intent. I see no reason it can't also be a platform for experimental propulsion since it doesn't HAVE to go anywhere. We are not planning a cruise. If the propulsion is faulty or needs redesign, I'll eventually fix it. Might need to fix or modify it more than once. The air prop was tongue in cheek. :D
    HOWEVER! In addition to the azimuthing pod electric prop and the Flettner rotor and the single yard loose footed lateen sail (A Sunfish sail with both a yard and a boom isn't lateen but a crabs claw technically) One more gizmo.
    I'm leaving the original prop shaft in it's shaftlog. Just in case I or a future owner wants it original. So why not use it? I have a heavy, spoked ships wheel of steel about 3 ft diameter. I'm considering putting a skinny 24 to 30 inch, two blade model airplane prop on one end of original shaft and the ships wheel on the other as a flywheel. Row myself back to the dock with it, if need be. If that's not clear, I'll spin the ship wheel by hand as fast as I can to run the prop, but hopefully flywheel inertia will help so I'm not exhausting myself. The 2 blade prop can lock up and hide behind keel when not needed. On anchor or at dock, the wheel is for grandkids play, otherwise it's nautical decoration.
    Up till now you probably suspected I might be nuts. now beyond shadow of doubt, you can be POSITIVE! :D

    Oh! Your reference to tacking lateen? Did you mean like a dipping lug sail? Yard is too long to dip, on the lateen, IMO.
    As to reefing the lateen by binding the sail at the yard ends, I have noticed that in photos too. But I believe they MUST bring that high yard end down to deck to reef it. Teetertottering the yard again! Either that or lower entire yard to reef and rehoist. I know which of the two tasks I would prefer! :D
     
  3. Sailor Alan
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    Sailor Alan Senior Member

    I knew i had heard a 16" X 16" model airplane prop would work for a pedal boat, and here it is.

    http://www.recumbents.com/wisil/hpb/compact_drive.htm

    There were a couple of pedal powered mini house boats here in lake union (downtown Seattle), and they may be still around. There was quite a movement here promoting pedal powered boats for a while, but people seem to have returned to rowing (which i prefer) and paddling (which i don't).
     
  4. Yobarnacle
    Joined: Nov 2011
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    Yobarnacle Senior Member holding true course

    The bronze 3 blade prop original to my boats is 17 inch so I'm thinking larger needed in two blade low rpm. I'm not expecting to get up on plane by whipping a spoked wheel around like a vertical playground merry-go-round. But if I can get 1 or 2kts by hand power, that would be a nice redundancy. I don't plan to voyage to the Bahamas like this, but a few hundred yards from a mooring to a dock is doable. My diesels are heavy flywheel, compression release, hand crank start as well as electric start. So dead batteries aren't an issue. Angular momentum hand power is just another experiment on the same platform.
    I also enjoy rowing, and sculling. But not an easy option with 8.5ft beam. I'd need a lifeboat oar and have to stow it. And install a thwart and stretcher and could only row one side against a hard over rudder. Not impossible, but I think the spoked flywheel prop will likely work better. I'll try various prop sizes till I stumble on the best choice. They are cheap enough at Hobby King. Carbon fiber up to 32inch diameter.
    http://www.hobbyking.com/hobbyking/...ist=&sortMotor=&LiPoConfig=&CatSortOrder=desc
     
  5. Sailor Alan
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    Sailor Alan Senior Member

    Just a moment; do i understand your to have a Diesel engine, manual and electric start, AND an electric motor both on your current shaft with a 17” prop? this sounds feasible, and given a clutch between the diesel and shaft so the electric motor does not try to drive the diesel, would work well. The electric motor could be non exited, hence no drag, or exited, and generate electricity at some power loss to the propeller. Both these power options should use the same propeller, just different RPM depending on power.

    Now how are you adding a human power option. I was imagining you somehow had a redundant shaft, and could then sit sideways (so the pedal shaft axis and propeller shaft axis were the same) peddling a chain reeducation drive down to this shaft with the model airplane propeller on it. Changing propellers on the original shaft when you wanted to pedal occasionally would be hard and time consuming work.

    Optionally, you could calculate the RPM needed for your current boat propeller to absorb, say 1/2hp, and gear a bicycle pedal chain set down to that, onto the main shaft. As long as the diesel was clutched out, and the electric motor had no excitation, the only resistance would be windage and perhaps the diesels gearbox. This latter would be the killer, so you really need the chain drive to the propeller shaft “last’ on the shaft, and to be able to physically disconnect everything ‘behind’ that.

    Ive seen some pretty fantastic propulsion systems on marine vessels, triple engine driving one shaft, gas-turbine and diesel on one shaft, steam turbine and steam reciprocating on one, or separate shafts, diesels that reverse rotation, but your is getting close to an all time high. Well done.
     
  6. Yobarnacle
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    Yobarnacle Senior Member holding true course

    I had better explain in multiple posts so my thoughts and words don't get jumbled.
    You give me too much credit.
    Because I don't have all this on a single shaft.
    I do have a redundant shaft I plan to hand power.
    It's the original 30mm shaft that drove the 17 inch dia X 10 inch pitch, 3 blade bronze prop via 20hp Albin diesel thru a 2.5 reduction velvet drive gear. This engine, red gear and prop have been removed and saved. Engine and red gear need rebuilding. They have been soaking in hydraulic fluid (principle ingredient in Marvel Mystery Oil) since last September. Hopefully I can unfreeze them THIS September when I return to Florida.
    This 20hp diesel has compression release, a handcrank for hand start, and a combination generator/starter motor for electric start.
    I plan to install them in 2nd Albin, STOWAWAY, after rebuild. It also has the 30mm shaft and a 2nd identical prop but currently engineless.
    Stowaway does have electric drive, a failed experiment comprised of two (80lb thrust each with original plastic 2 blade props) EngineMount trolling motors (mounted to my keel)spinning 11 inch dia, 10 inch pitch 5 blade aluminum British Seagull props.
    She has 10 old salvaged batteries converted to alum. The PWM controller FRIED after about 100 hours operation in 2012. That boat has been in storage since.
     
  7. Yobarnacle
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    Yobarnacle Senior Member holding true course

    I also have a 10hp Albin diesel, compression release, handcrank, combo DC gen/starter for electric start. It is nearly identical to the 20hp except one cylinder instead of two. Many parts are interchangeable between them. I had this engine checked by pro mechanics and they pronounced it perfect condition.
    I intend to install this engine in INTREPIDOS, the Albin I'm modifying to an extreme. No major modification to hull and NONE to hull form. I have removed all seacocks (8) and glassed over all underwater thru hull openings. I have a keelcooler for the engine so it can be freshwater and antifreeze cooled. I'm converting to dry stack exhaust. I have removed the small spade rudder and glassed over where it's shaft penetrated the bottom. I purchased a transom mount rudder of 150% larger immersed blade area.
    Pers Brohal, the designer, said the rudder was too small to sail well under just sails.
    Now the only remaining perforation in the bottom is the shaftlog and it's prop shaft.
    As much as I'd like to have ZERO holes under water, I have been reluctant to eliminate the original shaft log/prop shaft. So, I thought of using this shaft as a hand powered prop. Not pedaled, but a hand spun flywheel.
    Raised 3 daughters and 2 stepsons and have to date, 8 grand kids. I am the motive force for the playground merry-go-round. It has been my career for more than 30 years. My job was only a diversion from my true calling, merry-go-round spinner.
    With so much experience whipping around faster and faster, a heavy spinning kid laden wheel, for hours at a time, why wouldn't it work driving a propeller?

    Drawing below is oversimplified and not to any scale. The ships wheel is shown direct connected to prop shaft but will actually connect through chain sprocket or vee belt pullys.

    The engine/gen set and azimuthing electric drive are just crudely sketched in, for clarification they are not driving same shaft.
     

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  8. Yobarnacle
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    Yobarnacle Senior Member holding true course

  9. Sailor Alan
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    Sailor Alan Senior Member

    I realize you are well along on a multi-year project, but i would approach your current armada a little differently.
    I applaud your re-use of resources, and i hope the 20hp Albin comes clean as it were. I found i needed to disturb the oil occasionally, bubble air through it perhaps, to get some positive movement of oil between the stuck parts. I also used Turgasol for final cleaning, but i suspect this is unavailable now.

    Personally, i would put one diesel engine in each boat, 10hp in one, 20 in the other. I would mount one troller motor on each boat, and split the batteries between them as well. Now you could consider a car alternator geared suitably to each main propeller shaft, such that it drives the shaft at the RPM appropriate to the standard propeller absorbing the power produced by the car alternator.

    Now you have a diesel motor with generator, driving a larger electric motor/alternator (also charging the batteries), driving the main propeller on each boat. You also have a complete back up troller motor from the batteries for each boat.

    The inverter is going to be the problem. These have a rating, and one dares not exceed it, even for a millionth of a second. Even the most trivial issue can create a ‘spike’ on the cable quite capable of ‘frying’ an inverter. Using the car alternators as 3 phase brushless motors is good and cheap. i will have to check compatibility between car alternators, troller motors, and other modern permanent magnet motor/generators.

    Now you install a rig on each boat, probably an ‘A” frame lateen, though i would prefer a Gunter lug, as the spars are shorter and easier to handle single handed. I think i would use a single mast for the following reason.

    Now, attach the two boats end to end, using the leaf springs from a modern Ford truck. These are carbon fiber, do not rust or corrode. Connect them as far apart as you reasonably can, side by side, and with the bolts/bushings horizontal and athawtships.

    This should link the two boats solidly in line, but having flexibly in vertical travel. Use standard rubber bushings for out of alignment.

    Now you can set sails on both vessels in line ahead, and if you arrange planks over the leaf springs, you can easily walk from boat to boat. In this case the lager rudder will be useful, as you are steering the whole 50-55’ long rig. Either one, or both diesel motors could be run in tandem, as could the main electric, or even the troller motors. Or even any combination thereof!

    For greater physical convenience, attach the boats using the above leaf springs, stern to stern. In this case, both rudders will need to be centered (or removed, in the case of the transom hung version). Now stepping from boat to boat would be cockpit to cockpit, with or without a plank etc. In this case, steering could be achieved by altering the length of the two leaf springs, or perhaps better, altering the length of hydraulic pistons. This is similar to steering a Swedish Military Vehicle,

    http://www.sw-em.com/Snow Weasel.htm

    Now the fun part. The rig on the aftermost vessel would be reversed too, either the lateen set with the tack at the stern of the aftermost boat, or the Gunter Lug set over the foredeck of the aftermost vessel. If you want to get extreme, drive the main propellers forward on the front boat, and in reverse on the rear boat at sailing speed using the electric drive. Equally, you could engage the forward boats diesel, and the rear boats diesel in reverse, and run under diesel power. Ditto, full electric, or troller (auxiliary) electric.

    If you really insist of having a ‘merry go round’ powered propeller, make it a ‘long shaft’ and simply hang it over whichever piece of boat is the stern at the time. Alternately, and this is my favorite, have the ships wheel turning a vertical shaft, with a right angle gearbox and propeller, possibly repurposed from a British Seagull OB, attached via clamps to whichever part of the boat you want to ‘push’ even if it is a stern at the time, aim the propeller appropriately, and spin the ships wheel.

    Admittedly, this rig would be for relatively calm water, though more wind would not bother it. As soon as there was any chop, you would have to disconnect and tow as you described earlier.

    I would use tarpaulin sails, white/grey, with 12 tows/inch, and 100mph tape to seal seams etc. This is sometimes described as ‘cargo liner tape’, and is available from Boeing surplus. I have used it exclusively for sail repair, occasionally stitching it round when i got a chance. Gorilla tape also seems to work well, but i have limited experience.
     
  10. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Thankyou for your thoughts. The Albin 25 does not have an aft cockpit, but has an aft cabin. Putting them stern to stern would not make crossing over easy.
    Posted below is an Albin 25 under sail and a photo of the enginemount double trolling motor.
    These trolling motors I have are not easily separated and even working together only propelled the Albin a tad less than 5 kts under motor alone, and that while using/spinning 11 inch 5 bladed Seagull props, one on each. And enhanced with Kort nozzles/wheel guards. They did function well motorsailing, running a few amps over "nuetral'. Eliminating the drag of the props, added 1 to 2 kts to my sail speed, and much improved control. No getting caught in irons while tacking.

    At anyrate, I believe I have the plan pretty well jelled. it has been my intention all along, to put one diesel in each boat.

    I need a new PWM controller for the trolling motors. The original burned up.
    Was it because I was using a bank of 3 lead/alum batteries at 11.5 volts each instead of 2 lead acid at 13 volts?? These motors need 24 volts. Or did I discharge the batteries too low, that the voltage dropped and amps increased until too hot? Or was it the load of those big aluminum 5 bladed props? Or did I damage the motors resulting in destroying the controller? Or all of above? Anyway, I have been sniffing around to pick up a used PWM controller. No joy yet.
     

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    Last edited: Jul 8, 2014
  11. Yobarnacle
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    Yobarnacle Senior Member holding true course

  12. Sailor Alan
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    Sailor Alan Senior Member

    First i am extremely impressed you got nearly 5kt from those trolling motors. That is nearly hull speed, and very impressive indeed.

    As typical commercial inverters are current limited, i cannot quite see how you could have overloaded them to the point of failure, ie even at lower than normal voltage, they should still have protected themselves via current limit.

    Did you make sure there was clear air flow too and through the inverter. High local heat is the usual cause of failure. Did you ever note the current when the boat was at nearly 5kt?

    I am also impressed your motors could spin 5 bladed Seagull props. I thought 5 bladed Seagulls were the ‘Century Plus’ series, and 5hp or better? Those troller motors, with which i am not familiar, I've never seen such a twin setup, do not look like 5hp each to me, but you must have got near that to get near hull speed in your boat.
     
  13. Sailor Alan
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    Sailor Alan Senior Member

    Further news. You need not ‘sandwich’ the foam on your intermediate disks. There are any number of airplanes (small ones) out there that use ribs made from 2-3” thick blue builders foam as is. The fabric wing skin is often held on with ‘Mactac’ though if you use the metal strapping mentioned earlier this is unnecessary.

    I am extremely impressed with the lighting truss, and its performance (thank you Hans). I have assumed the car/trailer axle base would be attached to the boat with some flexibility, i.e. rubber bushings, so the rotating ‘mast’ top (top spindle) could move a few inches in any direction. This is to absorb any boats usual flexing under sail loads. Your FG cabin top is far too thin for the lower spindles local load, so i envisioned a ‘platform’ on the cabin top, possibly 4” X 4” timber (temporary) with the axle base bolted to it using rubber bushings.

    Now i wonder, now the lighting truss seems so good, could we arrange it as a ‘free standing’ mast. This means, could the cabin roof, and the aforementioned ‘platform’ be strong and stiff enough to resolve the forces involved? Equally, could the bottom end of the lightning truss be strengthened and stiffened enough to carry its local loads. Im sure the trailer, or car axle bearing will be enough, but it has a fairly small base on the chassis side at least, i.e. i doubt wood would be stiff enough without very substantial washers. Daiquiri please chime in here.
     
  14. Yobarnacle
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    Yobarnacle Senior Member holding true course

    Actually, I'm considering moving the rotor to the stem area. More space, more strength, less likely someone gets road rash from touching it. Thinking on it, but not yet decided.
    If you remember my Albin requires very little HP at slower speeds. Yes, the 5 blade hydrofans are from the century seagull. like all IC engines, it's rating at 5 hp was at top speed, 4000 rpm. The small one cylinder motor didn't produce 5 HP at lower rpms, and maybe NEVER! Engine MFGs have been known to exaggerate. :) And many expert folks have doubts about the Seagull Century ever producing an honest 5 HP.
    And electric motors have high torque at low rpm, and the gear box on the century was 4 to 1 reduction, while the electrics are direct drive.
    I don't know why the PWM controller burned up. I was lulled into a false confidence and not watching it, because everything was working so well, for maybe about 100 hours or a little less, spread over many days of testing. Then, one afternoon, it started stinking and quit. ???? Too hot to touch.
    I was pumping more than 24 volts into it, more like 33 volts when batteries were fresh.
    Also, the props had shrouds. Not exactly Kort nozzles, but ducted never the less.
    Another aspect is, how much thrust does a gas outboard produce per horsepower? I have read all sorts of estimates ranging from 20 lbs per HP, to 70 lbs per HP. These trolling motors produce max of 80lbs thrust each with little plastic 2 blade props, weedless (inefficient) variety. With the ducted, barge pusher, Seagull hydrofans, I expect it was quite a bit more thrust. I observed a LOT more prop wash! But even at the 160 lbs rated thrust for the doubled motor unit with oem props, that equals several horsepower worth of thrust? Maybe even close to an equivalent thrust of a exaggerated "five" horsepower gas outboard.
    A lot of outboard motor mfgs detune larger HP motors to sell "smaller" rated motors. It really is hard to compare gas outboards to trolling motors, or any electric drive, when it's entirely possible the gas motor maybe a 10 HP in disguise as a 5, or a fudged 4 HP,
    One more thought. Hybrid car MFGs use an electric motor of less HP than the gas engine in the same car non-hybrid model. Some a third less some a third OF, it's claimed. Why?
    The only pure electric and same gas model I can find, is the 200hp electric Tesla and the 190 hp gas version Elise. I'd love to see more data. I find LOTS of opinions.
     

  15. Yobarnacle
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    Yobarnacle Senior Member holding true course

    I would like the lighting truss mast to be free standing and able to spin.
    If I used a fiberglass drum shell imbedded in the deck, and sealed at the bottom but equipped with overboard drain. Would some big washers made out of plastic cutting boards, to spin with and support the truss vertical inside this circular well, be stiff enough?
    I have some 12 inch diameter, 8 inch high FRP shells I can spare. Would 8 inch depth be enough, or would I need two shells superposed for a 16 inch bury of truss base?
    bearing would be attached bottom of well. I could line the fiberglass well with a cylinder of thin stainless steel as a wear plate.
    I would install in bow close to stem, so I could brace well to inside stem and hull sides with small bulheads and short struts.

    I could set a lateen aft for balance, if the rotor forward made steering weird.
     
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