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Senin, 14 Maret 2016

The Incredible Self Steering Ellie

Yesterdays daysail was one of the best sails Ive ever had. It was a beautiful and interesting day. The day started off with very little wind.  I had to motor-sail from the launch, but a short while later the afternoon breeze kicked in like someone flipped on a light switch. While I sailed towards Hat Island, the wind steadily built until I finally had to heave-to and don my rain gear. Later, as I rounded the NW side of Hat (Gedney), the wind calmed down and it turned into the most pleasant of conditions.

You know those conditions.  When the winds are a steady 10 knots, the seas have calmed, the sun is warm on your face. The only sounds are the waves on the hull, the breeze in the rigging, the occasional cry of a gull, and all those utterly delightful little squeaks and creaks that only a wooden boat can make.

Those are the conditions that cause the mind to wander, much as they once did for Albert Einstein.   Einstein, in the summer of 1939, was seeking a unified field theory to unite his general theory of relativity with electromagnetism. He spent many hours aboard his 15 foot wooden sailboat Tinef (Yiddish for "worthless" or "junk,") lost in thought, forming his theories and exercising some of the thought experiments that he is so well known for.  As I sat aboard my own 15 foot wooden sailboat lost in thought, I wondered if there could possibly be anything that Einstein and I had in common.  Perhaps how we both enjoy sailing small wooden boats and how we both experienced the way the peace and solitude caused the mind to drift.  Then I realized how reassuring it was that even a genius like Einstein can still be a poor sailor, like me.

I daydreamed about self-steering.  Long ago I had read that a yawl can self-steer all by itself.  No wind vane steering mechanism.  No sheet-to-tiller steering.  No tiller tamer.  No auto-pilot.  No bungee cords.  A properly designed yawl, I vaguely recalled reading, can somehow be made to steer itself just by setting the sails some certain way.  But how?  How are the sails set?  How does it work?  And was it really possible or just a legend?

It had to be some sort of balance between the jib and mizzen, I reasoned.  They would have to be set in a way that would cause the boat to round up if it were to fall off, and fall off when it rounded up. In between, the boat would have to sail balanced.  That means the boats natural weather helm would have to be neutralized.  I knew that could be done by easing the mizzen.  Hmm.  Time for a thought experiment of my own. What if I kept the main and jib sheeted in tight but eased the mizzen out until the helm was neutral?  How would the boat react?  Seems like shed sail straight with a neutral helm.  But what would happen when she veered off course?  I imagined when she fell off, the mizzen would catch more air which would then turn her back into the wind.  When she headed up, the mizzen would catch less air, begin to luff and lose power, and then the jib would cause her to fall off.  Thats it!!!  Shed self-balance.  It made sense.  It seemed like it would work.  All that was left was to give it a try.


And much to my amazement, it worked!  It really, really worked!  For over an hour, while I ate lunch, recorded some video, took some photos and enjoyed the sun, Ellie cheerfully sailed herself.

Initially I had a small line going from the tiller to a cleat, but it didnt seem to be doing anything, so I removed it.  Sure enough, Ellie still self-steered completely unassisted.  I tried shifting my weight around.  I sat on the front thwart, I stood on the aft thwart.  Didnt matter - it still worked.


I never touched the tiller in all that time until I finally had to call an end to it, or run aground on Camano Island.

No doubt there are experienced sailors out there who would pass this off with a yawn and a shrug and a "nothing to it, I do it all the time".  But they would be missing the great joy that I experienced yesterday.  The joy that a fellow mediocre, but thoughtful sailor spoke about when he said:

"Joy in looking and comprehending is natures most beautiful gift."
-Albert Einstein

Lastly, I hope you enjoy this little bit of my delightful sail home.





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Minggu, 28 Februari 2016

Power steering part II








Im still waiting for the auxiliary drive adapter from John Deere. On Thursday, the Deere marine dealer called me to let me know the part had shipped, so I should see it on Monday as it was shipping from Ashland KY. Im not in a big hurry for this part, but if I were depending on this type of service or made my living off of getting repair parts in a a relatively short time, Id be quite pissed at Deere about now. Ive owned CAT equipment all my career, and to be honest, no one can hold a candle to how fast CAT gets parts to contractors. Im not going to beat this horse any more, but Ive never waited more than 24 hours for a CAT part.... NEVER.

All the hydraulic lines Im able to install without having the drive adapter are installed. The lines had to pass through two water tight bulkheads en route from the engine room to the helm then to the steering quadrant. I used bulkhead fittings to get through the bulkheads and maintain the water tight integrity of the bulkhead. The bulkhead fitting also breaks the lines down in to shorter runs, which helps the manageability of the system.

A few things are starting to look like I did some things right in the previous stage of the build. It has turned out to be a good thing that I bolted lumber to my steel framing to screw the various floors too. Ive had all the engine room floor plates many, many times, and having the lumber to screw the floor panels too, vs screwing to the floor material directly to the steel framing, has made removal and replacement of the panels a breeze. I held the lumber proud of the steel framing by 1/16th of an inch, so I dont have any aluminum touching any steel which should help with rattles. The lumber is also making running mechanical systems much simpler and quicker as it is much easier to run a screw in to the lumber for attaching clamps vs through bolting through the steel. The lumber to steel idea has for sure made my life easier. I still have water lines, electric lines, and more hydraulic lines to install beneath the sole, and I know it is going to speed things up and make a hard job easier due to having the timber frames bolted to the steel frames.

Because my lines are fixed between bulkheads, and no line will see any movement, I have a feeling the hydraulic lines will last many, many years. The only place I will have movement of any parts is at the steering quadrant. Because of the slight movement the steering quadrant will have upon the hydraulic lines, I decided to use a short jumper line between the cylinders and a bulkhead fitting vs having a long line directly from the water tight bulkhead to the cylinders. I attached a two inch piece of angle iron the the aft wall, and used two bulkhead fittings to make the connections. Since I have some hydraulic hose left over, Ill probably make a spare line for this area and in case the movement in the quadrant causes a line to fail prematurely. So I have a relatively set of long lines starting at the water tight bulkhead terminating at the angle iron bulkhead fitting, then two short jumper lines connect to the slightly moving quadrant.

I installed the seven gallon reservoir underneath the work bench next to the engine. I threaded a filter in to the reservoir, and have the return circuit running through the filter. The reservoir has a site gauge on it with a built in thermometer. To make filling the reservoir easier, I extended a 1" fill neck with a vented cap up to the work bench elevation. The " low " level on the site gauge is 4" above the pump elevation. The pump needs to be gravity fed and it was critical to keep the oil level above the pump at all times.

I kicked around the various routes I had to get the hydraulic lines from the engine room to the helm and back again for while before I committed to install the lines. I decided to run the lines from under the engine bed, through the water tight bulkhead @ the center of the boat, then up the wall of the master cabin and in to a chase in the master cabin ceiling. Im going to have to create a chase to hide the hydraulic lines that run up the master cabin wall by the water tight door, but this will solve a few problems in doing so. Ive decide to use this newly created chase to run the throttle control and shift cable controls for the main engine. I also will use this chase to run the hydraulic lines for the deck winch. The ceiling chase is getting crowded, but I know I have enough room to install the shift and throttle cables. I am questioning if the winch hydraulic lines will fit in the remaining space since those are 1/2", and things are getting tight up there. I do have another framed ceiling chase next to this one on the other side of the longitude ceiling beam, so I can always use that chase. The unused chase Im speaking of is going to be for my DC home runs from the engine room, and the AC lines feeding the air conditioner that will reside under the steps.

Im clamping all the hydraulic lines using galvanized rubber coated clamps and stainless screws. Any place I have four lines running together, I clamped two of them with the steel clamps, then used plastic cable ties to tie the remaining two lines to the better clamped set. Any place I have two lines, I steel clamped one line, then cable tied the other to it. I had ordered two boxes of clamps from the Parts Connection, and the other day, I gave one of them back. This week on one of my visits to the Parts Connection, Im going to get back that box as Ive been burning through the clamps. I dont want any moving or chaffing of these hydraulic lines. Any place I installed lines through metal framing ( when not using bulkhead fittings) I hole sawed through the metal and installed a rubber grommet. 1 1/4" grommets were a little tight for two 3/8" lines together, so I upped the grommet size to 1 1/2"

The size of the steering wheel is something that has been eluding me, and I really dont know how big a wheel I want. I mocked up a few sizes, but am afraid to commit to anything. I found a used 18" destroyer wheel on Ebay, and paid the stupidly cheap price of $1.00 plus $12.00 in shipping. The wheel is missing the cap, but I could lathe one out of Cherry, and call this a done deal. At least I can use the wheel to test the steering as soon as I finish the job and get the engine ready to fire. Hard over to hard over on this steering system will be about three turns, so a large wheel is not needed for torque. 18" might work, but seems a little small to me.

The helm is mounted to a piece of 18" channel welded and braced to the floor. All the helm cabinetry will be in Cherry, so you wont see that beautiful piece of channel steel. The channel makes for a nice stout mounting tower for the helm and hydraulic lines, and thats all I cared about.

I dont think installing the pump drive adapter is going to be a big job, so I am looking to have the steering system wrapped up by next weekend. Ill post some more once I have the drive adapter installed. I might connect the exhaust at that time and fire the engine.


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Jumat, 26 Februari 2016

Rudder and Steering



The rudder on my trawler is a rather large device. The approximate dimensions are 2.5 wide by almost 5 tall. Having installed the rudder a few times Im going to guess its weight at 200+ lbs. The rudder looks more like a wing and is constructed in such a way as to have two skins wrapped around the wing shaped frames. It is very sleek looking and more reminds me of a sailboat rudder vs a rudder you would see on a work boat. Compared to the rudders I see on house boats around my home port, this rudder has a tremendous amount of square footage to aid the steering of the boat. By looking at the rudder alone, I would guess this boat will be very responsive to the steering wheel. Becuase of the way the rudder is fabricated it is impossible to paint the inside to protect the steel. Because of this type of rudder construction I air tested the rudder to 10 psi to insure that no oxygen gets inside of the rudder and speeds up rust corrosion.

The rudder is connected to the boat via a large skeg or shoe that is an integral part of the keel. The rudder has 2" stainless stock welded to itself that is flanged on both the top and bottom of the stock. The bottom flange bolts to another flanged piece of 2" stock that sits in a bearing in the skeg. The top flange bolts to piece of 2" flanged stock that passes through a bearing that goes up into the lazzarette of the boat ( rear room) and connects to the steering gear. The flanges for the rudder system I fabricated out of 3/4" stainless stock and bored them to accept 5/8 bolts to hold them together. Ill have to design some sort of locking ring to retain the nuts or use a castle type nut with a key to hold the nuts fast. The bearings for the rudder in the skeg and where the rudder stock enters the boat @ the lower end of the rudder log ( rudder tube) are made from a material called Vesconite. Vesconite is designed just for this application and is claimed to be top of the line material for what Im trying to do with it. I will not have any galvanic worries with this type of rudder bearings.The rudder tube terminates inside of the boat about 8" above the water line. I added another bearing at this point of termination for a total of three rudder bearings. With the rudder installed Im able to move it with just a little pressure from my finger tips. Im totally happy with the bearings and the rudder alignment. Because of the mix of a stainless steel rudder shaft and mild steel boat I will add a zinc or magnesium annode to the rudder to slow down any galvanic corrosion.

The actuall steering system on the trawler will be what most would consider a power steering system. My main engine has a port on it to accept a pump that will power the steering helms that in turn will power the hydraulic rams connected to the rudder shaft. I will have two helms on my boat; one helm in the wheel house, and another helm on the roof as a fly bridge. In case of a catastrophic failure of the steering system, I have an emergency tiller device in place to steer with ( see my earlier post " emergency tiller"). The hydraulic rams are more a heavy duty set up I purchased from Hydro Slave Co. The steering gear consists of a heavy cast bronze quadrant, two hydraulic rams, and an integral arm to limit travel of the rams. If you look at the first picture posted you will notice my attempt at rudder stops welded to the hull. I know they look a bit odd, but at least I made some attempt at aero dynamics and they also wont increase any corrosion issues. The quadrant connects to the rudder shaft via a heavy clamp and a 1/2" stainless key way and key. I went with this type of dual ram set up becuase it causes zero side load on the rudder shaft. I am totally pleased with this piece of equipment, and while it was pricey, I feel it was money well spent. Ill be adding to this blog once the steering system is fully connected and operational with the helm pumps in place along with the hydraulic lines.

Conall
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