As you read this week’s Progress Update below you will understand what I am referencing in this week’s title as to how we solved the most recent challenge in the building of XPM78-01 Möbius by going under rather than over the problem. Unfortunately on Friday (did it matter that it was the 13th?) we were hit by a much different and much more challenging problem which there is just no getting over, around or under, when several workers at Naval Yachts tested positive and there was no choice but to shut the whole company for the next 17 days and do all the contact tracing and testing of all those employees who have been in direct contact. If all goes well Naval, and certainly Christine and I, hope to reopen on November 30th. I’m sure you join us in wishing everyone involved the very best wishes and that there are no serious health consequences for any of us here.
To be clear and not cause any undue concern on your part, as good fortune would have it, neither Christine or myself have had any direct contact with any of these workers for the past two weeks. Furthermore, we have always been very self disciplined with our precautions of wearing masks any time there is any possibility of being in a place with others or where others have been recently such as the elevators in our apartment. We are both quite naturally introverts and previous single handed sailors so it has been relatively easy for us to keep to ourselves and staying as much as possible. And we are both quite fit and healthy, especially for two sixty somethings so I am pleased to let you know that we both feel very fit, healthy and happy and are doing everything we can to stay that way.
This may be as my kids used to say “TMI Dad!!”, as in Too Much Information to share, but the value of these kinds of blogs come in large part through their openness, transparency and honesty so I felt the need to share this brief insight into what is going on here and why there will not be much progress to report on for the remainder of this month of November. Hopefully all will go well and Naval will reopen on Nov. 30th with all of us healthy so we can hit the ground running and get Möbius finished and launched ASAP.
Now back to our regular programming as I think they used to say on radio and TV, as I do have several fun and exciting things to update you on from aboard the good ship Möbius for the week that was November10th through 13th.
I think it is quite true that laughter is the best medicine so let me start by sharing this fun cartoon, courtesy of the appropriately named Bizarrow Comics who focuses on such topics as Pirates, Cowboys, Snowmen, Doctors, well you get the idea.
This was one of their Daily Comics this past week and it must have been making the rounds on the internet as several of you sent this to us right about the same time Christine and I were both seeing it. Thanks Matt et al!
How appropriate and fun for us right?
Getting Under Mr. Gee
Let’s move on to the reference in this week’s title to a problem that we were able to solve by going under rather than over it. To put it in context, this was part of Hussein and I working on the alignment of the whole “propulsion” unit formed by Mr. Gee being bolted to the Nogva CPP Servo Gearbox which in turn is bolted to the big 65mm / 2.6” SS prop shaft which has the big bronze 1 meter / 39.4” four bladed CPP prop on its far end.
That is a long description that is hard to track and I have received quite a few questions and comments about both the Nogva CPP (Controllable Pitch Propeller) and this whole alignment process so for those interested, let me break it down and provide more details.
Here is my very rough sketch from over a year ago when we were figuring out the exact dimensions for installing the aluminium Nogva Prop Log which is the “pipe” you see over on the far Left here.
I’m hoping that this will give you the big picture view that helps to show how this Propulsion System is one solid mass from the front of the Gardner in Blue on the far Right, through the Nogva Servo Gearbox in Brown in the middle with the two flanges connecting to the Fwd/Right end of the prop shaft and over through the Prop Log, out through the end of the skeg where the CPP propeller in Green sits.
Here is the dimensioned drawing from the Nogva engineers I worked with to design this custom CPP system for Möbius. It shows how the Propeller Shaft runs inside the larger inside diameter Prop Log Tube
This is the drawing above with some of the many dimensions I was pulling off of the actual installation at the time so I could double check that my 3D model of all this was exactly the same dimensions as the real deal.
No need for you to pay any attention to all these dimensions but I thought that this front to back view might be helpful for those trying to visualise this whole setup and see the relationships between all the individual parts.
Next up, let’s take a look at the six anti-vibration “feet” or mounts where Mr. Gee and the Nogva CPP are attached to the 25mm/1” thick engine beds running the full length of both sides of the Engine Room.
I have never had enough time to create a full 3D model of Mr. Gee so you will have to use your imagination in the blank space to the Left of the Red Nogva Servo Gearbox, but hopefully this quick render of my Fusion 360 model will help you see how these six feet connect the whole Propulsion System to the Hull.
I initially created this 3D model when I was designing these custom brackets that bolt to Mr. Gee’ thick cast AL crankcase and create the eXtremely strong and rigid attachment points for the vertical threaded adjustment rods on each foot/mount. Front mount is on the Left, Rear on the Right and both of these feet/mounts are the same anti-vibration models with thick rubber isolation blocks inside.
This is what those Front & Rear anti-vibration mounts look like and of course Mr. Gee requires the MMXL version!
Back in the real world inside the Engine Room, this is Mr. Gee’s Front Port/Left foot after we have lifted the whole Propulsion System up with big chain hoists to drill the holes for the M16 Grade 8 bolts that will hold each mount solidly to the Engine Beds in precisely the right location Fore/Aft and Left/Right.
Here is a closer view of the mounting bracket I designed to be welded into the underside of the two Engine Beds and how these two different style of feet connect the Nogva CPP Servo Gearbox to the Engine Beds and Hull. Also a good shot of the output flange on the Aft end which is what need to get so precisely aligned with the matching flange on the forward end of the Prop Shaft.
Here is what these highly specialised feet/mounts on the Nogva look like in the manufacturers catalogue before I purchased them. These start out being the same as any other feet/mounts by providing the rubber isolation that separates the upper body with the threaded rod from the metal base that bolts to the Engine Beds. However if you look closely you will see that there are also two large diameter SS pins going side to side across the Base through the elongated oval shaped rubber isolation block.
Here is a bit closer view one of those two Nogva feet in my hand to try and show you those two pins and the rubber isolation block. Why are the Nogva mounts different than Mr. Gee’s some of you have asked. Because in addition to providing the anti-vibration connection to the Engine Beds these also deal with the very significant THRUST forces which would otherwise be trying to push/pull the whole Propulsion System fore and aft as the propeller “bites” into the water and pushes the boat forward or reverse.
The Nogva Servo Gearbox is built to be mounted solidly to a hull with no anti-vibration mounts in large commercial vessels so it also has its own thrust bearing setup inside to fully deal with all these eXtreme Thrust forces. However with one of our first principles being Comfort, the addition of these specialised thrust feet/mounts will help eliminate the transmission of vibration and noise to the hull and make for an eXtremely smooth and quiet boat when underway.
Good shot of the custom Rear brackets bolted to Mr. Gee on the Left side and the underslung bracket for the Nogva feet/mounts over on the Right.
Putting it all together, this shows you the whole Port/Left side of the Propulsion System with all three mounting brackets and their feet/mounts.
But hang on a minute …………………………………………
………………………… what the heck is that underneath Mr. Gee?!?!?!?!?!?
So what was the problem that required raising the whole Propulsion up in the air and me spending all day Thursday up close and personal with Mr. Gee’s underbelly?
Well, as Murphy’s Law would have it, when Hussein drilled those two holes for the middle two feet on the Aft end of Mr. Gee, they turned out to be right on top of a 15mm thick vertical AL stringer running down the length of each Engine Bed. Ugh! This meant that while the threaded ends of the mounting bolts could go through there was no space for the washers and nuts underneath!!! Grrrrrrrrr
Going back to this render you can see that 15mm vertical stringer underneath the Front foot/mount where it was NOT a problem as the mounting bolts are further off centerline but if you follow that stringer Aft/Right you can see how it runs right through the centerline of the two bolts in the Aft Foot/Mount on Mr. Gee and hence this problem.
The solution? A rectangular slot was going to need to be cut into the stringer where it was welded to the underside of the Engine Bed to create enough space for the thick washers and nuts to slide into.
We tried to solve this problem by going Over the Engine Beds but as you can perhaps see, there wasn’t enough room to get in there with drills, Dremel tools, chisels and files. We could have used a plasma gun but it would have spewed molten aluminium all over the Engine Room so that was a non-starter.
*someone* was going to need to go at this problem from the UNDER side. As you may recall from seeing Hussein in some previous posts and down below, there as simply no way HE was going to fit in there, so guess who was elected??? No recount needed by the way!
With the Propulsion System firmly blocked up on all four corners I could pull out some of my Houdini moves and slither into this space with my headlamp and use various WMD, Weapons of Mass Deletion, to cut a rectangular slot in the vertical stringer under the four bolt holes. I was one pooped Pirate when I finally got home to my Captain at the end of the day but it worked as planned and there was now plenty of room for the nuts and washers for the bolts for these two middle feet/mounts to thread into. Whew!
Going back in time a bit, in order to lift the whole Propulsion System up in the air so I could get underneath to cut those four slots, Hussein, Nihat and I had rigged up these two lengths of square steel tubing that Nihat had welded large D-rings to the middle underside and spanned the big hatch in the Aft Deck.
We then hooked a large chain hoist onto each D-ring and connected their bottom hooks to straps around the front end of Mr. Gee and the built in lifting eye on the Nogva.
It all worked very well and also gave us a very safe and precise way just barely to take the weight off of the six feet/mounts so we could move them in their Goldilocks Just Right locations as we fully align the two flanges which is the next step in this process.
ALIGNING the PROPULSION SYSTEM:
This is the first part of the alignment challenge: get that male threaded end of the CPP Pitch Push/Pull rod coming out of the center of the Prop Shaft, PERFECTLY aligned with the female threaded Pitch Piston protruding out of the center of the output flange on the Nogva Servo Gearbox.
The prop shaft and pitch rod are fixed in position so they can’t move Up/Down or Left/Right, they both just rotate concentric with each other. So the alignment has to happen by changing the angle of the Propulsion System.
It is a slow and exacting process where we slide the feet/mounts to adjust the Left/Right position of the centre of the Nogva Pitch Piston/Flange and then adjust those big adjustment nuts on the vertical threaded rods on each of the six feet to change the angle of the Propulsion System and move the centre of the Pitch Piston/Flange Up/Down in the process.
It took several hours going back and forth from measuring and checking the Aft end here and then into the ER to tweak the six big adjustment nuts but as you can see here, we eventually hit the Goldilocks Jackpot and had the Push/Pull Pitch rod dead on center and ready to be threaded into the Pitch Piston.
It was slow going turning the Pitch Piston with a wrench on those two flats so the bulb finally went on for me and I blocked the end of the wrench in position and then went outside and down to the Propeller and kept pressure pushing it forward while I rotated the bit 4 blade prop as if it were some eXtremely long bolt and that worked perfectly.
The last bit of precision is to get the length of that exposed threaded section of the Push/Pull rod above, to be precisely 7.5mm away from the aft end of the hex locknut as per the Nogva installation Manual you see here. It can actually be between 5-10mm so I set it at the middle of this range at 7.5mm and torqued the locknut down to 100nm.
* for those curious, “Servo bevegelse 50mm” is Norwegian for “Servo Travel = 50mm”. 25mm on each side of “neutral” or Zero Pitch.
With the Pitch Push/Pull rod all centred and locked in place I could now put on the two split halves of this Red Prop Flange and start the second phase of the alignment process. This has two components to it; getting the mating flange surfaces precisely parallel to each other and also getting the two flanges equally perfectly aligned with each other axially.
These two figures from the Nogva installation manual shows these two alignments very clearly and as you can see it needs to be eXtremely precise, no more than 0.05mm / .002”. FYI, this is the thickness of THIN human hair.
This will all be sounding very familiar if you were with me two weeks ago when Hussein and I when through the exact same process in order to find the precise location of the base of each foot/mount so we could mark out the location of the holes for their respective bolts. This is a photo from that previous alignment and when we, hopefully, all get back to work on Nov. 30th we will do as Hussein is doing here and use thin feeler gauges to measure and ensure that the gap around the full circumference of where these two flanges mate, is exactly the same. I.e., they are perfectly parallel. To get there we go through the same adjustment procedure I outlined for getting the Pitch Push/Pull rod center aligned by sliding the feet Left/Right and/or turning the threaded adjustment nuts Up/Down.
I know this is not riveting stuff for almost any of you but this is such a critical part of having a smooth quiet Propulsion System that it gives me tremendous joy and satisfaction. Fortunately it is also not a process you need to go through very often so well worth the investment in time now.
Nihat was the only member of Team Möbius on hand this four day week but he is one of our most relentless workers so he finished all his work on the Port/Left side of the hull and moved around the Bow to pick up where Uğur had left off last week.
You can see the multi stage process quite well in this shot. First the welds along each butt joint of the hull plates needs to be ground flat and flush such as you see running along Fore/Aft just below Nihat’s belt line. Then any work marks on the surface of the plate need to be ground off which leaves a finish like the one on the far Left here.
This nose on shot of the Bow shows the Start/End of this whole process with Nihat just getting started on the Left side of this photo (Stbd/Right side of the hull) which is in contrast with the surface finish on the opposite side that he has fully finished with a random orbital sander.
Here is a shot looking straight onto that same finished surface. The Waterline is about 200mm/8” above the weld at the bottom so that does not get fully ground down flush as this will all be covered wtih epoxy primer and International InterSleek 1100 foul release “Bottom Paint”, so we can use filler to get all the surfaces below the Waterline flat and smooth prior to painting these surfaces.
You Made this Bed; Now Lay in it!
None of our interior crew was available this week but the big memory foam mattress has been cut to size and the cover sewn up for over a month now and it was going to be much easier to get it onboard before they put in all the glass windows around the Pilot House/Super Salon so I was able to get a strapping young worker from the boat next to us helm me wrestle the mattress aboard.
As is often the case with boat beds, their sides are no parallel and this was the case with the Right side here as it runs parallel with the side walls that curve in with the hull. But Sinan our master upholsterer was able to quick cut the foam with his special electric knife and then resew the cut edge of the very nice mattress cover so it all fits in like a glove.
It was actually much easier than I thought it might be. This is 30cm / 12” thick memory foam so we were able to bend it and flex it just enough to get it through the Entryway WT Door into the SuperSalon and then down that spiraling stairway into the Master Cabin in the background on the Left.
Captain Christine has not been able to be onboard for over a week so it will have to now wait until after Nov. 30th for her to come test it out.
When you get out of that Bed, Test out this Helm Chair!
For similar reasons I wanted to get both our big Llebroc Helm Chairs aboard before the glass company arrives next week to install all the SuperSalon glass windows and all the plexiglass windows around the whole upper SkyBridge.
This is the LLebroc Tradewinds CX HB SERIES 2 Helm Chair now resting in its new home in front of the SkyBridge Helm Station.
We also moved the slightly different and just as cool Llebroc Bandera Series 2 Helm Chair into the Super Salon Helm Station but I didn’t get a chance to take any photos so you’ll have to wait till we get back onboard for me to show you that beauty.
It felt very good for me to be finally moving things like these Helm Chairs onboard to their final resting place as it makes the Launching of Möbius feel that much closer and real. I had the same feeling when I was also moving these three 18 litre/5 USG cans of hydraulic steering oil onboard on Friday. This will soon be filling up our 55L hydraulic steering oil tank that feeds our whole Kobelt steering system and I’ll show you that as it happens.
Next up were these three cans with almost 60 liters / 15 USG or one of my favorite engine oils; Shell Rimula R4X 15W-40.
In addition to being a top quality engine oil I have found this to be one of the easiest brands to find most anywhere in the world as this is also commonly specified by the big diesel engine companies for use in tractors, trucks, cranes, etc. that are needed and used most everywhere.
I also moved all our anti-freeze onboard but didn’t get any photos, which I’m sure you are all so sad about. Not!!
And that’s all from your intrepid cub reporter here in Antalya Turkey for the week that was November 10 through 13th, 2020. Hope you enjoyed this week’s abbreviated posting and I will be back with more next week.
Please do keep your questions and comments coming by typing them into the “Join the Discussion” box below. They are eXtremely helpful and meaningful to both Christine and myself and MUCH appreciated. Thanks!