Another busy week here at Naval Yachts for all of Team Möbius as we ramp up for the final push to launch as early in the new year as possible. It remains a labour of love for Christine and I but it certainly is all consuming of our time and attention. This week saw progress in everything from CNC machining the new Tiller Arm now that the Rudder is pretty much finished and ready for installing in the hull to finishing the installation of the prop shaft tube into the hull, plumbing for the in-floor heating system, wiring and of course lots of cabinetry work. It will take me awhile to get through it all for you so grab a beverage and a comfy seat and let’s go aboard Möbius and check it all out.
Most of our work with Aluminium to date has been with large plates which are CNC cut to shape and pieced together to form the hull and superstructure. However as you can see in this photo this hunk of aluminium beauty ain’t no plate!
If I tell you that this 152 x 255 x 275mm (6” x 10” x 11”) and 30kg/66lbs block of solid aluminium is just one half of the part, can you guess what this is going to be?
That 150mm/6” long 25.4mm/1” precision ground threaded pin is specially hardened steel to easily withstand the eXtreme forces which can be exerted on it where the Heim Joint ends of the cylinders attach to the Tiller Arm body. I ordered these and 2 spares from McMaster Carr and brought back with me from our recent trip to Florida.
A bit of a no brainer given the title of this section I guess!! A Tiller Arm.
These two quick screen grabs show the design I came up with using Autodesk Fusion 360 which I must say is my all time favorite design and drawing software of all time and in my case that is a LONG time!
You can see how the right side is the second half I mentioned and those four large bolts clamp the Tiller Arm to the 127mm/5” Rudder Post with the 20mm key that goes in the slot on the left side main body.
Turning on some hidden components you can see how the two Kobelt 7080 bi directional hydraulic cylinders with a bore of 76mm/3” ID and stroke of 305mm/12” provide plenty of torque as they push/pull the Tiller Arm which in turn rotates our big rudder up to 45 degrees to each side.
eXcessively massive, time consuming and expensive? Of course, this is an XPM! and the steering system is arguably the most important system on a passage maker so I’m delighted with such eXcess.
Each cylinder is connected to its own dedicated Kobelt/Accu-Steer HPU400 Hydraulic Power Unit. Dennis and I worked extensively with the great engineers at Kobelt to come up with this eXtremely robust steering system. We have designed it such that just one cylinder and one pump significantly exceed the steering requirements to safely steer the boat in even the most severe conditions.
There will be controls at each Helm station to allow us to select either Steering A or Steering B and our SOP Standard Operating Procedures will be to alternate using A and B for a week or so to ensure both systems are fully operable and being used equally. At any time for situations such as close quarter maneuvering we can have both pumps and both cylinders working at the same time which cuts our lock to lock rudder time in half.
In the unlikely event that both pumps and cylinders were to fail we then have a Kobelt 7005 manual hydraulic steering pump with wheel at the Main Helm. And if all of that were to somehow fail we then have an emergency tiller which can manually control the rudder.
Back to real time photos, the CNC machining is all happening in a building 2 blocks over from Naval Yachts here in the Antalya Free Zone at Tasot Waterjet Cutting Technology.
They have a small warehouse filled with some of the most advanced metal cutting machines of every description and having the literally next door is one of the great advantages of building here in the Free Zone.
Here is the whole gang responsible for transforming my design into a very real aluminium Tiller Arm. From right to left, Yigit our XPM Project Manager, Hamdi Uysal CNC machinist, Ufuk Bekci Tasot Owner and Tuncay Mutlu Production Engineer
This is the 5 axis CNC machine in the middle of machining the body of the clamp block.
Closer view of the Clamp Body with one side finished and ready to be flipped over to machine the other side.
Hamdi proudly showing the finished Clamp Body.
One half done, now on to the Tiller Arm Body.
With one side of the main Tiller Arm body finished, roughing out the second side begins. Easy to see why this is called “subtractive manufacturing”. 3D printing is the opposite “additive manufacturing”.
Here is a short little video I’ve put together to show you what this looks like in action.
I was too busy on Friday to get back to see the finished Tiller Arm body so I’ll show you that in next week’s update.
Meanwhile back at Naval Yachts, the Rudder is all finished and patiently waiting to be installed as Nihat and Uğur ae busy getting the 10mm thick walled 200mm ID Rudder Tube tacked in place as they prepare to insert the finished Rudder.
Choosing a few relevant layers in the 3D model and using “ghost” mode this quick render will help you see how the various pars such as Rudder, Prop, steering cylinders and Tiller Arm fit together. This is in the aft end of the Workshop with the door out to the Swim Platform in the upper left.
In reality mode here is the Rudder Post Tube now tacked in place and just sticking up above the Rudder Shelf. Same Workshop to Swim Platform door on the upper left. Next week when the Rudder Post Tube is fully welded in place you’ll see the Rudder post sticking up through this tube with the Jefa self aligning needle bearings top and bottom and the Tiller Arm on top.
Looking underneath the Rudder Shelf reveals the 25mm/1” thick AL brackets which tie the Rudder Post Tube to the stringers, frames and prop tunnel of the hull and make this all one integral hull assembly.
Limber Holes or ”Mouse Holes” in the corners where these tube braces will be welded to the hull plates ensures that any water which finds its way in here can easily flow to the lowest point and be removed by the bilge pump and not trapped in these compartments.
PROP SHAFT & LOG MOUNTING
You may recall from an update a few weeks ago that the machined Aluminium tube, the one with the holes in it here, which the Nogva CPP prop shaft runs inside of, had been fitted into the larger aluminium prop tube that is part of the hull which you can see running up to the top left corner here.
See something new though?
What’s that Orange stuff in that little stubby bit of pipe?
And what might this bit of kit be that is on the floor just below the prop shaft tubes?
And what are they mixing up here?
Some of you will recognize this quite universally used Chockfast Orange which is a special 2 part compound which is pumped in fill voids between two parts and rather permanently fasten them together once it hardens.
After being thoroughly mixed with the hardener the syrupy Chockfast Orange is poured into the red tank you see in the photos above, the lid is bolted down and the tank is filled with compressed air.
Then a tube connects the bottom of the tank to the filler tube which is temporarily welded to the hole in the top of the hull’s prop shaft tube and the Chockfast flows into the 12mm/ 1/2’” space between the outside of the Nogva Prop Log tube and the larger inside diameter of the Hull’s larger welded in prop tube.
Up inside the Engine Room, the other end of the prop tubes which have been precisely locked into position with this clamping jig and a tube has been inserted into the pipe that has been temporarily installed where the two tubes have been sealed off to stop the Chockfast from leaking out.
A few minutes later the Chockfast has filled the entire void between the two tubes and exits out the tube. Several cupful’s are collected to make sure any entrapped air escapes and then the valve on the Chockfast tank is turned off and we leave this to fully cure in the next 48 hours. Once fully hardened the two tubes become essentially a single part and provides plenty of space for water to surround the spinning prop shaft at its center.
With the Chockfast fully hardened the prop shaft was fitted again to double check the position of this red flange which will soon be bolted to the output flange of the Nogva CPP gearbox.
Where the prop shaft exits the prop log tube there will be a “dripless” seal that fits over the end of the prop tube and seals against the spinning prop shaft to keep all water where it belongs; in the sea and outside the boat!
A close up view of the threaded push/pull Pitch rod which runs inside of the prop shaft. This rod threads into the Nogva gear box and is moved fore and aft by the Pitch Control lever at each Helm. As the rod moves fore/aft the four prop blades rotate in synch and changes the pitch to anything from neutral, forward or reverse and as more pitch is added the speed of the boat increases. All a very simple and mechanical system which gives us the ultimate prop, one that is perfectly pitched for any condition.
At the propeller end of the prop tube, water exits out these holes drilled around the circumference of the machined end of the Nogva prop tube.
Next week the Cutlass Bearing which supports this aft end of the prop shaft will be press fit into place and the CPP prop and shaft assembly can be carefully slid in place for checking of the final fit as we prep for installing the Nogva CPP Servo gearbox.
One of the many items in that big crate you saw arriving from Florida last week was our Kenyan “Frontier” 220V electric grill that is part of our Outdoor Galley on the Aft Deck. We no sooner took the box out of the crate than Nihat and Uğur whisked it away and cut in the opening for the grill in the Starboard/Right Vent Box.
Deciding to go all electric for this BBQ was part of our ability too make Möbius be a single fuel, all diesel boat. The other big part of this was going with an internal diesel engine in our Tender and I’ll have more for you on all of that in the coming weeks.
All the top surfaces of these two Vent Boxes on the Aft Deck will be countertops, probably using some of the left over turquoise granite from the Galley countertops. There will be a SS sink in the open space you see here in front of the grill.
Speaking of electrical, I only managed to catch a few shots of Hilmi and Okan’s progress with some of the wiring this week. Okan was busy in the Basement prepping these cable trays to be mounted on the ceiling which will be used to support those huge 120 mm2 / 5/0000 AWG red and black cables.
Cihan was also a busy boy this past week installing plumbing pieces for several different systems.
He has masterfully crafted these two manifolds for some of the Cold and Hot water systems for moving water from one of the six tanks to another as needed to adjust ballast as fuel is removed and others for getting water from the watermaker you saw last week, to each of these tanks.
He has done a beautiful job of insulating all of these to increase efficiency of the DHW Domestic Hot Water lines and also keep the Cold water lines from absorbing ambient heat in the Workshop when we are in hotter tropical climates.
Moving forward to the Basement, more of Cihan’s fine work this week was getting the dedicated Galley Water tank in place. This is probably more “eXcess” as we can hold as much as 7100L/1875USG of potable fresh water in our six integral tanks in the hull and we have the 190L/hr / 50USG/hr Delfin watermaker.
However as you’ve read previously and often, we always design with our “Readiness for the Unexpected” in mind and this additional 200L/55 USG polypropylene Potable Water tank is one example. We will treat this similar to the Day Tank for our diesel fuel by keeping it full at all times and it will be plumbed to an independent faucet at the Galley sink.
Wonder what that shiny item sitting atop the Water tank is? Yet another bit of kit out of that crate from Florida, this is the manifolds for the three in-floor heating zones. To my eyes it is a beautiful work of art in its own right and is almost a shame it is down in the Basement where not too many eyes will see it. The top 3 red towers are flow meters which you adjust with the white knobs on the bottom.
After some discussion, Yigit, Cihan and I decided this would be the best location for these manifolds, secure against the WT Bulkhead with the Guest Cabin on the other side.
Supply of hot water enters on the top right and goes out to each of the 3 in-floor zones from the bottom of the Red upper manifold and then returns through the three fittings under the White knobs and back to the Domestic Hot Water system on the bottom right. Ball valves on all lines coming in and out and temperature gauges on both supply and return so I can monitor the difference.
Each zone has one of these 3 speed 1/25HP pumps on the supply side to keep the water circulating through the 15mm PEX lines embedded in the floors.
In the foreground on the left is a Watts mixing valve plumbed into the floor heating water system to help manage the lower temperature water needed for in-floor heating which wants to run between 30-500C/85-1200 F.
In the background is the Azel I-Link three zone Pump Controller which is controlled by individual temperature sensors embedded in each cabin floor.
I’ll have more to show you as Cihan progresses with the installation.
My Beautiful Bride, aka Captain Christine is at the shipyard most days now and here she is going over the details for the cabinetry and fixtures in this Guest Cabin Head/Bathroom.
Standing in the Guest Shower for this shot you can see that Omer has been practicing his cabinetmaking craft very well in this Head. With the Guest Cabin serving as her Office the majority of the time and with this Head being so close to the SuperSalon entrance and the aft Workshop, it will likely get more use than the Head in our Master Cabin so worth making sure it has the Goldilocks touch of being “just right, just for us”.
Christine spent a LOT of time searching for this just right sink and finally found one and had it shipped to me in Cannes when I was helping out Naval at the boat show there back in October and I brought it back on the plane with me.
Raised platform in the back is where the VacuFlush toilet will rest at the Goldilocks height.
Up in the SuperSalon Omur and Selim continue to make great progress. Here Omur is putting in the perimeter framing for the rigid foam insulation on each stair tread leading down into our Master Cabin.
All the floors have 40mm/1.6” thick rigid foam board which the 15mm PEX tubing is embedded into and then some of that light weight poplar 10mm marine plywood covers that and the edges of the plywood attach to these epoxy coated solid wood frames.
Opposite the stairs where Omur and Selim are working you can see how this white framing also provides the perfectly level foundation for all the cabinetry to mount to.
By week’s end the wall boards were being fitted and will give you, and us, a better sense of how this room will look.
The large opening on the far right is for a 50” high def monitor which will serve double duty as both our primary entertainment screen for displaying movies, photos, web browsing, etc. However it is also on a 3 axis mount which enables us to pull it out and rotate it forward where it is perfectly aligned for viewing charts and boat data from the Main Helm chair when underway.
The large vertical openings on the far left will soon house two Vitrifrigo 130L/35USG fridges with doors opening from the center. The center cabinet is for two of Vitrifrigo’ s band new DRW70 70L/19 USG slide out drawer freezers which can double as fridges with a simple change of their thermostats.
Over in the Cabinetry Shop I happened to catch Omer as he was gluing up one of the Galley drawers and shot this sequence of shots for those of you who have been asking how the wood “biscuits” I’ve been mentioning work to align and strengthen the glued up wood joints.
You can see 2 biscuits with freshly applied glue on the right….
One of the drawer sides which has a matching grove for the biscuit is slid in place.
Same thing for the opposite side.
Two biscuits and some glue for the final drawer side.
Thanks to the ingenious biscuit power tool which cuts all these grooves everything lines up just right. The biscuits are made from highly compressed wood fibres so as they soak up the glue they expand and make the joint even tighter and stronger.
Rinse and Repeat the process and this collection of glued up drawer carcases starts to form. Once the glue dries plywood drawer bottoms slide into place and are glued and screwed in position to create very stable drawers which slide in and out on their ball bearing self closing slides with just a touch.
Remember that crate we build and filled with all sorts of parts and equipment that we were sourcing out of the US and arrived last Friday? Uğur helped me open it up and unpack it all this week.
Literally hundreds of items inside from Milwaukee cordless tools for me to premium Belgium made pots and pans for Christine and then LOTS of parts for Möbius and they all made it on their flights from Miami to Antalya just fine.
Two of Möbius’ items whose arrival we are most excited about are these two bright red beauties from Electrodyne. I have been working closely with the fabulous people at Electrodyne Inc. for well over a year to have them build these eXtremely heavy duty 250A 24V alternators for us which combined will put out almost 14kW. So when I say that we don’t have a generator onboard I guess that’s not entirely true?!
** WARNING: mini Tech Talk Ahead! Skip over if not interested
I’d known Electrodyne alternators since I was working as a HD construction mechanic in my youth and Electrodyne alternators were the ultimate choice for large construction and mining diggers, railroads, trucks, busses, emergency vehicles where they often ran 24/7 for weeks or months. They are literally built like tanks and each one weighs 40kg/90 lbs!
I’d initially worked with Pete Zinck until he retired early this year and turned things over to his Production Manager Dale Gould and who could not have been more helpful and responsive to my many Emails and requests.
What you are seeing in the photo above are two identical Electrodyne G250-24 models which are de-rated down to 250Amps @ 27.5V @ 3750RPM which would give each one a maximum output of almost 7kW (6.875) for a combined output of almost 14kW. However I will make the serpentine pulley ratios such that their max speed will be about 3200-3400 RPM for even longer life. Dale stripped these down for safer, and slightly lighter shipping and I have not had time to mount the HD steel wiring boxes which house all the wire connections you see here for the six large external direct AC output cables which then run over to the external rectifiers and regulators which I will mount outside the Engine Room with thermostatically controlled fans to ensure they are always running nice and cool and at maximum efficiency. I’ll cover all that in the coming weeks as I get these alternators installed on Mr. Gee our Gardner 6LXB and wired into the electrical system.
I had a list of key features I wanted for our dual XPM alternators running off our single main engine and I knew that it was going to be a challenge to find a company that would build these so with my long past experiences with their alternators I turned to Electrodyne and sure enough they were able to built in all the features I wanted, In addition to being rock solid, high output and lasting “forever”, perhaps the most significant features that I wanted were that they be brushless and I wanted them to have everything other than the rotating stator to be external. No built in regulators and no rectifiers. Why go to such extremes? In a work; HEAT, which is the largest factor in shortening an alternators output and lifespan. Rectifiers can produce more than half the total heat within an alternator so by removing these and going with industrial grade 3 phase bridge rectifiers I can reduce the internal head of the alternator by more than half AND control the heat of the rectifier bridges outside the ER and with their own fans. This also creates an alternator with only one moving part, the spinning rotor so MUCH better airflow through the alternator stator windings and rotor. The Goldilocks alternator for an XPM; consistent high output with low heat and low maintenance.
I will cover these Electrodyne beauties in much more detail in future posts here once I get them all assembled and installed but suffice it to say that I am VERY excited about getting these Electrodyne alternators installed and tested. Equally as exciting are the WakeSpeed 500 Advanced Regulators that were also in this same crate of equipment we unpacked this week and will be controlling and managing our two mighty Electrodyne alternators.
If this stuff interests you as much as it does me then please stay tuned and be sure to subscribe to the blog so you don’t miss any of the new articles as they go live.
OK, now back to our regular programming.
Mr. Gee Gets Naked!
Captain Christine is now working at the Naval Shipyard with me most days now as we make the final push to finish this build and bet Möbius and ourselves back were we belong; ON THE WATER!!
Amongst her many jobs Christine has literally rolled up her sleeves, donned her HD latex gloves and become Mr. Gee’s personal degreaser! Our Gardner 6LXB serial # is 196071 which means he emerged out of the Gardner and Sons building in Patricroft in Manchester England in February 1975 and was in constant use powering a tugboat in the Thames river everyday thereafter.
After 45 years of such use we are giving Mr. Gee a serious bath to start his second life as our main engine in Möbius. To do so we have removed every single part, nut, bolt and cotter pin and have now removed pretty much every bit of grease and guck that has accumulated over his glorious 45 year past.
With all the other duties I’ve unexpectedly taken on here along with the regular demands of building a new boat I’ve not been able to get as much time as I had expected to attend to Mr. Gee’s needs but I am contributing more of late and managed to get this massive chrome molly (chromium molybdenum steel) crankshaft all cleaned up and returned to its original shiny self.
This is Michael Harrison, the CEO of Gardner Marine Diesel Engines who continues to keep the Gardner name alive and very well. Michael was also the one who found Mr. Gee for us after a very long search for this completely original unrestored marine version 6LXB.
The Gardner 6LXB, and most Gardner engines for that matter are built with four primary building blocks:
- Cast Aluminium Oil Pan
- Cast aluminium Crankcase
- Cast Iron Cylinder Block with pressed in dry liners
- Dual cast iron heads
After one of several strip downs, I had reassembled all these major castings and had the exterior thoroughly sandblasted and then put on several coats of high temp silicone based primer.
Now stripped down naked once again and ready for the bath of his lifetime, Hakan helped me drag the bare cast aluminium crankcase outside.
Armed with some super HD degreaser, lots of wire brushes and our newly acquired Bosch pressure washer, it was bath time!
I had spent the previous 3 days scrubbing every nook and cranny with the degreaser and wire brushes so this final pressure wash took us back down to virgin raw aluminium throughout. I also wanted to be sure to blast out every oil gallery and hole to remove not only the old grease and grime but also any new particles that had climbed aboard during the sandblasting.
And here is the result, a VERY clean Mr. Gee!
This is the front end of the crankcase which will soon be filed with lots of sprockets and an eXtremely large double roller timing chain that drives everything from the camshaft to the PTO for one of those Electrodyne alternators to the water pump and fuel pump.
Whew!! It is now late on Sunday night and I’m exhausted and so are you probably if you’ve made it this far!
Thanks so much for joining us, makes this adventure all the more exciting and rewarding to know you’re out there and along for the ride.
Do please add your comments, questions and suggestions in the “Join the Discussion” box below. Even though I am WOEFULLY behind in responding to those of you who have done so in the past 3 weeks. Rest assured I DO read them all and think about all you say and I will respond to each one in the next few days so thanks for your patience.
Wow! Wow! Wow! 🙂
Regarding steering setup,
Each Kobelt cylinder is connected to its own dedicated Kobelt/Accu-Steer HPU400 Hydraulic Power Unit. Thus, when running with low load, ie. close quarter maneuvering at a low speed and turning rudder fully from one side to another thus fully opening the hydraulic steering valves, the pump is pumping – relatively lowly loaded – at constant speed a constant volume of hydraulic fluid from one compartment of its associated hydraulic cylinder to another chamber in the same cylinder. The lock to lock speed is thus only limited by the pump displacement (constant) vs pump speed (constant) vs cylinder volume (constant).
Now running another pump and cylinder of same specs (displacement, pump rpm, fully open valves) in parallel should results in same rudder lock to lock time, not half, or what am I missing here?
The time would be half if the two pumps were driving one cylinder in parallel, but I guess the design is two fully reduntant, non-interconnected hydraulic systems with no cross feed.
Ahh, now you are discovering why it took us almost 2 years to design this steering system! 🙂 Short answer is that it is being plumbed such that we can chose between one cylinder and two and also change between one pump or two. I will publish more of the details, schematics, etc. as we start installing all this Kobelt gear and you should see how this all works as we do and can ask more detailed questions as this proceeds.
“In the unlikely event that both pumps and cylinders were to fail we then have a Kobelt 7005 manual hydraulic steering pump with wheel at the Main Helm.”
Is there a tertiary backup cylider for the manual steering pump? Does engaging this involve releasing the autopilot cylinders by some valve etc or how does it work if both autopilot pumps loose their power in a total blackout?
No extra third hydraulic cylinder Andy, so “just” the manual helm pump that could be used to steer the boat if both of the Accu-Steer pumps were to become inoperative.
Ok, makes sense – should be enough.
And regarding the alternator,
All that heat comes from low(ish) efficiency. Generating electricity itself does not produce heat. I am guessing your conventional alternator setup is around say roughly 50% overall efficient, so producing 14 kW juice takes roughly 28 kW mechanical energy. That means every 1% of efficiency improvement is 280W less heat to dissapate. Also every 2% of efficiency improvement should save you roughly 1dl of diesel per hour, or 20% improvement one liter, when producing at 100% capacity.
1. drive belt. V-type belt has always some slip causing heat, and this worsens with time as belt streches and tension decreases. Replacing with state-of-the-art toothed belt like “Gates Polychain Carbon ADV” will save around 5%-10% efficiency, plus the lifetime is longer and maintenance much less and belt is skinnier so much less audible noise.
2. alternator. Permanent magnet alternator is much much much better efficiency, brushless type even more so. We are talking like sub 50% vs. 95-98% here. All that difference is heat.
3. rectifier. Active ideal diode mosfet type rectifier is much much more efficient than passive diode bridge type. Diodes have inherent voltage step and thus loss and thus burn power. Mosfets do not.
4. controller/regulator. Conventional regulator driving alternator coils to directly regulate charging voltage is quite lossy. Much more efficient way is to let voltage freely float and then charge with DC-DC -converter, just like with PV-panels. In fact, Victron MPPT-controllers work just fine with wind turbine type alternators, and have been used that way. I am not 100% sure if this is officially supported config, but it sure works just fine.
Personally, I would mount permanent magnet alternator like this or similar directly around pro-shaft, next to Nogva-gearbox:
From manufacturer site:
– Rated power from 200 W up to 95 kW depending on size and rated speeds.
– Rated speeds from 80 RPM up to 1500 RPM.
– Six overall diameters from 145 mm up to 795 mm.
– Internal diameter from 56 mm up to 630 mm.
– Various available voltages up to 500 Vac.
– Frameless design: one rotor and one stator to be integrated inside user’s mechanics
– No speed multiplier, no gear
– No maintenance
– Highest power-to-weight ratio in Direct Drive
– High efficiency
– Simplification of mechanical design
– Easy mechanical interface
– Cost optimization
When producing 14 kW electricity, heat difference would be 14 kW of heat vs. 750W of heat, and 3 liters of diesel per hour. And for peace of mind, conventional alternators could be kept as a spare, and for heating up the engine room at high latitudes.
Sorry if you were planning a more detailed post and I commented “too early”, but we can continue this discussion then more 🙂
And with such super impressive wizardlike aluminium CNC-skills inhouse, you could as well easily manufacture a custom direct driven aluminium CNC-machined axial flux -alternator/generator collar around the propeller shaft, with low RPM and large diameter and properly with care done windings, high 90s, even 98-99% efficiency would be achiavable.
Quite right I’m sure Andy. However what I can’t manufacture is more time! I’m hard up against there only being 24 hours in each day here and we need to stay focussed on getting this boat finished and in the water. As you might expect I have a long and growing list of things I very much want to build and make for Möbius but they are on the list for “Phase II, III, IV………” of Project Goldilocks. 🙂
Good writeup on Axial Flux generators:
Never too early for questions and discussion Andy. I don’t have time right now to looking over the Alxion alternators you reference but I’m sure the short listed set of features you kindly copied here is accurate and they are very efficient alternators. My quick visit to their site didn’t show me any photos of what these alternators actually look like and how they can be driven but in any case, I’ve long since made my call on going with our two Electrodyne alternators. No question they are “old school” but for me and the XPM’s that is a “feature” and not a “bug” when it comes to systems that are so critical to our lives at sea. Efficiency only counts when you can use it and when it is working and so while our Electrodyne alternators may be less efficient than newer approaches such as these Alxions, I am much more confident and sleep much better at night knowing that my Electrodyne’s are most likely to “take a lickin’ and keep on tickin'” and that when they don’t I can fix them onboard.
If you’re interested in the regulators we are using, you can check out the links I put in to the WakeSpeed 500’s that we will have connected to the Electrodyne’s. I know I am WAY overdue in posting the more detailed Tech Talk posting on our battery and charging system and I’ll cover the Electrodyne alternators and WakeSpeed 500’s in that as soon as I can carve out a few more minutes here. So just as you suggested, we can continue this insightful discussion more then.
Thanks as always for your thoughtful comments and ideas Andy.
These particular alternators from Alxion are of frameless type, so it means it is just the stator and the rotor and the mounting has to be devised by the builder:
The rotor is fully passive, just a sturdy aluminium ring with permanent neodymium magnets along the circumference. This needs to be mounted around the rotating shaft with a suitable adapter, or it could be mounted around some existing suitable part eg. the flywheel of engine. The rotor will not heat during the operation.
The stator is a similar aluminium ring sized to closely fit around the rotor, but with copper windings in place of magnets. These are then connected in series and they form three phases, and can be connected either in delta or star config depending on the voltage required.
The voltage coming out of stator at nominal power is around 250 VAC. This can be recrified with a conventional diode bridge with relatively minimal losses because of the high voltage, as diode voltage loss is constant, not dependent on input voltage.
After rectifying, the high DC-voltage is fed to a suitable DC-DC charge controller, for example a Victron MPPT controller with 250VDC input rating would do fine.
The system has very few moving parts, none additional moving parts really depending on how you define a moving part. It is extremely simple and very very efficient, and because of that wont generate much heat, and that little heat is spread over large area around the stator ring and thus easily conducted away – so no cooling fans needed. Only thing that could maybe potentially fail is the charge controller, but then you can choose a quality brand and also carry a spare. And maybe the rectifier, but that can be oversized and will most likely last lifetime of the boat, and spare can be had at any electrical/car parts store. The permanent magnets and the winding coils definitely will last forever.
This is something that could be a grear fit for the high efficiency Gartner engine, and could be added later at a suitable time – maybe it could fit around the flywheel or the Nogva gearbox or some other suitable place. Would make most likely the highest efficiency grams of diesel to kilowatt hour of electricity making machine out there…
And from manufacturer site, “A full integration handbook can be supplied to our customers upon request”.
Thanks for the detailed explanation of these Alxion alternators Andy. I have no doubt, especially with your endorsement, that these would be very efficient energy engines. However, even though it all sounds quite simple and easy to fabricate the mounts and other components it takes to create the finished install, it is just too much time and trouble for me to add to my already long list and it is also too fraught with potential problems with such a custom and unproven setup in our conditions and use case. Not a knock on this setup Andy, just the reality of me being the only one who does all this and maintains all this. So while perhaps a bit less efficient, I remain convinced that our choice of a pair of Electrodyne alternators is the “just right, just for us” choice.