Model Boat Mayhem
The Shipyard ( Dry Dock ): Builds & Questions => Navy - Military - Battleships: => Topic started by: Oldishseadog on August 13, 2014, 10:40:59 pm
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Following on from my first posting under the Chit-Chat banner, for those that are interested some more thoughts and details on the Fairmile C project. Obtained the plans on three sheets by John Lambert – great detail of the real thing and construction methods, but translating into a scale model gives much food for thought. I chose the Fairmile because I like the hull form, curves and flare of the bow; in order to keep those lines it has to be a plank on frame/bulkhead build, decided to double-diagonal as per the original.
Once that was sorted, how do I power it. First thought was a diesel/electric arrangement, but after some investigation decided the scale was too small and the generation/power supply/voltage regulation was far beyond my meager electrical knowledge and abilities. IC by itself is noisy and problematical with going astern unless gearbox is introduced, but can do without that type of complication. So electric it is.
Model boat electrics have moved on considerably since my early efforts in the late 60s/early 70s so after considerable research, a lot of which was on this fine forum, I decided on brushless outrunners with lipo batteries. Four of them. Props will be outward turning (ie right-hand props on starboard shafts, left-hand props on port shafts, as per traditionally viewed from astern). Outboard props will have ahead and astern, inboard props ahead only; the intention with the electronics is to have the inboard props cut in at half-throttle or so. She will take 40 mm props no problem, may even take 45 depending on clearances, but that will be looked into once the hull is planked. Twin rudders, independently controlled. No helm mixing on the throttles. I used to drive multi-engine vessels for a living so tank steering and split rudders is the way to go (I have stopped short of fitting a bow thruster). Thrust bearings? Why not.
Not exactly how the original craft was configured, but I can live with that.
So, how to squeeze it all in? Looking at the available motor mounts and considering other options I decided to utilise cage-style motor mounts designed for model aircraft – very light but robust; bolt the motor on one end, the shaft coupling within the cage, the thrust bearing on the other end of the cage. The tubulars of the cage clamped to the hull structures. It will be easily removable as a unit and should make replacement or up-sizing of the motors fairly straightforward if necessary. There are a couple of photos attached of the experimental drive train. The motor is a 1050 rev per volt outrunner rated at about 220 watts with a 40 mm prop. Four cages will fit neatly across the beam of the boat at just about the LCF (slightly forward of it to be precise) so trimming issues should not be too great. Some drawing extracts of the motor arrangement are also attached.
Now the drive train is sorted, at least in theory, the current job is designing and drawing the keel structure and the lower part of the transverse frames/bulkheads. I want to try and get as big an opening in the deck as possible to give good access to the innards. Ideally I would like the deck structure completely removable from about frame 3½ aft to about fr.12 but I am still looking into the feasibility of this and the best method of waterproofing the joints, and how to secure the removable section in place – I have a few ideas but not fully developed any of them yet. Hence only the bottom half of the frames being designed at the moment.
It's going to take while to complete the overall design and form of the individual components so I am nowhere near introducing bits of wood to a saw blade, but that will come. Still got to make space in the garage to build it, my nearest and dearest wouldn't appreciate me taking over the kitchen worktops indefinitely! I'll post an update on design aspects for anybody interested when things have advanced suitably. {-)
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I look forward to this build but am I missing something here?
The Fairmile C had three Hall Scott engines!
Puzzled
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OSD........
1. are these the thrust bearings you mention?
2. some detail reference to the motor mounts [cage-style motor mounts designed for model aircraft] would also be interesting.... :-))
Derek
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If you haven't started building, Christian (CDC) does a fibreglass hull in 1/24th scale.
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I look forward to this build but am I missing something here?
The Fairmile C had three Hall Scott engines!
Puzzled
According to Lambert and Ross, Fairmiles C's did only have 3 engines. I'm fairly certain we're looking at a thread title typo and it should be "Fairmile D".
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Very interesting project. Let me know if you want a GRP hull and deck I can do all the Fairmiles in 1/24th scale.
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Christians hulls are good, I have his Fairmile B in 1/24th.
Very nice
Also think your looking at a 'D' rather than a 'C'
:-))
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Thanks :-))
The section drawing above shows a Fairmile C but with 4 props, 3 is correct.
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Yes, there is a bit of a liberty being taken with the powertrain - the first post on the project offers some background intentions towards the build, here
http://www.modelboatmayhem.co.uk/forum/index.php/topic,48175.0.html (http://www.modelboatmayhem.co.uk/forum/index.php/topic,48175.0.html)
The cage mounts for the motors are from here
http://www.giantshark.co.uk/product/169683/xyh-motor-mount-for-28-30-size-motor (http://www.giantshark.co.uk/product/169683/xyh-motor-mount-for-28-30-size-motor)
the ones I was sent were black, not as pictured. I have used a mix of two different sized mounts in order to get the cage long enough to take the shaft coupling.
Yes Derek, the circled item is the thrust bearing.
I had pondered on whether or not to go for a pre-formed GRP hull but decided that drawing, designing and building the hull from the John Lambert plans would be a challenge and ultimately more satisfying, although I am sure there will be times to come when I will regret that decision!
OSD
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April 2015
Things have moved on over the last few months and basic design of the hull frames and girders has been completed to the point where timber can be cut. The deck is designed to be removable from frame 4 aft to frame 12 to give access to the innards; deck superstructures, fixtures and fittings will be added later so as not to interfere with the opening. Weatherproof sealing of the deck removable section will follow the system used for hatch covers of commercial cargo vessels – convex rubber compressing against a horizontal surface. Will it work for this boat? Who can say – it does in my head and on paper but reality may prove to be different. If so, a bridge to be crossed at the time.
I've decided to install permanent sterntubes for the propshafts – brass tubing through the hull likely epoxied into place through which the actual bought-in propshaft/tube will slide with close tolerance, secured and sealed by a run of solder. Should the shaft tubes need to be replaced it will save having to wreck the hull to get them out. At least that is the theory. I may end up having to make a couple of my own shafts – they need to be 22.5 inches long and the longest I can find commercially available is only 20 inches. Yet another challenge. A-frames will need to be fabricated later in the build once shaft alignment is fixed. Currently in the process of knocking up a building board.
A few grabs of plans attached – the shape of the prow will be developed during the build – the plan shows a best-fit ellipse which is not true to the actual craft. Frame shapes printed onto paper and the paper pasted to the timbers for cutting; saves a lot of time; couldn't be doing with transcribing the drawings onto the timber – in any event the frame shapes are quite complex. More as and when things have moved on enough.
OSD
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Nice drawings. Look forward to the build.
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hi there
When I first saw this drawing, like everyone else, Fairmile C - 3 shafts - and then a little bell began to ring - I know there was a Fairmile C used on the St Nazaire Raid but I don't think she was altered mechanically to 4 shafts. However, there was an article somewhere along the lines about the Blockaid Runners or the Ball - bearing runners to Sweden during WW2. I know they converted several vessels and I am certain/sure one of them was a Fairmile C which I think may have been operated by the British Army i.e. Royal Army Service Corps and I wonder if this one had been mechanically altered to increase speed. I very much doubt it though, as I haven't found anything positive about it yet. I have found something about the Boat called Grey Viking which was used - I am sure Christian will know :-) .
Look forward to the build.
Aye
john
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Hi John
How goes it? best Camper Nick blockade runner website is the Paxman-Ricardo history page here;
http://www.paxmanhistory.org.uk/blockade.htm (http://www.paxmanhistory.org.uk/blockade.htm)
The 4 shaft C was never a reality as far as I know.
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It is now - at least in reduced form!
OSD
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Test post as seem to be having problems with latest installment
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November 2015
Two years have passed since inception – good job there is no rush.
Bought a cheap scroll earlier in the year and all hull frames, beams and girders have been cut. It is now just a case of working out the order in which to stick it all together. First-fit of the parts appears ok although there is a slight wave in the keel plywood which hopefully will be rectified as the hull becomes more rigid as construction progresses. Pictures speak a thousand words so here they are:
OSD
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and another
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and another couple
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And yet more ...
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I have learnt a lot from your design and cut of the frames and keel. I like the scarfe joint.
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Late August 2016
Progress on the old girl has been slow the last 6 months or so, mainly due to other calls on diy skills, but she is slowly coming together. The main framing of the hull is done and the keel is now suitably straight. The removable deck section has been cut free. Currently in the process of fabricating the weathertight seal arrangements to (hopefully) keep the water out of the innards. Engine mounts are in, prop stern tubes are not yet secured but seem to fit ok – a bit more work to do on the hull before confident to stick 'em in. Will probably work on fitting the electronics while all-round access to the hull is still possible before starting to plank (or maybe that is just my excuse for putting off planking for as long as possible!). Some photos of progress to date.
OSD
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All looking good OSD ...the engine room machinery layout is very tidy :-))...and your framing is very sharp for hand cut scroll saw work
The original vessels I understand were double diagonal planked in mahogany, which in our 1:24 scale and in two layers could be difficult to work with.......what specie of timber/s will you be using for the planking?
Whatever build speed you make....just keep the images coming through.... Derek
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looking great, the long build period will be your friend as advances in 3D printing over the last 2 years have been outstanding, fittings and guns are now available in precise and lightweight versions,(RN crews may be on the way from a designer I've been in contact with) think about a weight reduction program before planking, at 1/24 weight will not be your friend.. grams removed now will pay off later....
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Thanks Derek - sharp blade and changed often!
Not having done anything like this before I am not sure which timber to use for the double-diagonal planking, but after doing a bit of reading I am veering towards half-mil x 5 or 6 mil limewood, said to be good straight compact grain. Mahogany itself may be a bit too open grain and prone to splitting to be practicable. As the hull is going to be painted I am not too bothered about the visual appearance of the outer layer of planking. The top layer of the deck I may well try in mahogany and leave it bare wood - I have no idea if the deck on the real thing was painted, but my experience with wooden decks on proper ships is that they are untreated (in the days when they had caulked timber decks that is, rather than the utilitarian compound that seems to proliferate and readily break-up these days). Any wisdom to be offered over materials and methods would be gratefully received.
tghsmith - thanks for the comments re 3D printed fittings - I am a long way off that stage yet but will bear them in mind. I am hoping weight is not going to be too much of a problem; as she is now she is just short of 1.5 kg; hull form calculations (WPAs & Simpson's Rules) indicate a waterline displacement of about 4.5 kg. However, as mentioned above I have not done anything like this before so I will keep weight in mind (my calculations could always be wrong ...).
Thanks for your interest chaps.
OSD
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November 2019
Well, how time flies! I would love to say the old girl is finished and whizzing about a local pond but sadly that is not the case. Life has been such that things I like to do have been overtaken by things I need to do. Therefore the build has been taking very much second, if not third and fourth place, over the last two or three years. As I have said before, good job there is no rush. You never know, by the time I finish her there could be miniaturised nuclear fission cells instead of LiPo batteries and steam power will be all the rage again...!
Having completed all the framing and fabricating the rudder linkages for the split rudders (I know, I know … the originals had … but this is my build for my own amusement!!) I bit the bullet and started the planking. I decided to do a loose-fit base layer of vertical planks to get an idea of the hull shape and to fine out any irregularities. I used 10 x 1 (mm) limewood strip and Titebond 3 sticko and some of the strakes have been sanded down to almost see-through thicknesses in order to suitably fair the lines. But she is sound. Over the top went a layer of aircraft tissue applied with watered-down waterproof pva which seems to work quite well in turning moisture. I am now mid-way through the first layer of diagonal planking. Slight cock-up with the direction of the diagonal at first – that's what comes from working with the hull upside down and not fully thinking it through first (in other words, inordinate enthusiasm to get started) – but should have no serious effects on the finished hull. First layer of diagonal is 8 x 1 (mm) limewood and more Titebond 3 (just ordered my second 8-oz bottle); the intention is for the outer layer to be 6mm strip, which should just about be on-scale for the craft, probably 0.5 mm thick but I will see how well the first layer sands down before deciding. At current rate that should be about 2021 (year, not hour...).
I will probably trim the stem back and build-up a laminated stem-piece of hard wood to take the collisions she will no doubt have; that is way in the future but may go some way to explaining the slightly ragged appearance of the stem in the following photos. Talking of which …
OSD
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And some more pix ... some out of sequence
OSD
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That is a mighty complex set of brass Chinese nail retention & extraction tools there OSD, <*< ..........your own design?...the diagonal planking is also exceptional :-))
Derek
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HI Derek instresing build an four motors an sharfts that's what im fittin in on my tiger build but back to yours I gather this is meant to get up an go please keep pics comin
chris
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That is a mighty complex set of brass Chinese nail retention & extraction tools there OSD, <*< ..........your own design?...the diagonal planking is also exceptional :-))
Derek
Hi Derek, - brass bar clamps (Japanese!) on the keel with some home-made gizmos on them with M3 stud to give some screw-down pressure on the planks while the glue takes. Fiddly but effective, however v slow as only can do 1 plank at a time.
OSD
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Hi really great build so far - just wondering if it moved to another thread or sank into the covid mire ?? -cheers Pete
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Hi really great build so far - just wondering if it moved to another thread or sank into the covid mire ?? -cheers Pete
Well Pete, you have shamed me into putting out an update; the work is still in progress – thanks for your interest in the build.
May 2021
Both layers of diagonals have now been done, completed earlier this year. The prop shafts were soldered into the fixed sterntubes after the first diagonal layer. One problem I found with the diagonals was that with the compound curves of the hull the true diagonal (in my case 45 degrees to the waterline on the topsides) tended to drift and every so often it had to be corrected with tapered planks. On the final layer (6 x 0.5 mm limewood) I decided to do the planks in groups of 4 with every 5th plank spiled to fit. Fiddly but it kept the true angle. Another thing working with 0.5 mm strip – when the glue was applied the edges tended to curl with the moisture so holding it down flat while the glue dried also proved to be necessary. One plank at a time – hence the reason for more than a year to complete!! (The three layers of planking on the hull have consumed approximately 280 linear metres of stripwood).
The stem was trimmed back and built up with laminated mahogany strips – I was actually quite surprised and pleased at how well it turned out! In the photo the pencil marks show where the cocktail stick tree nails were positioned as the laminations were built up – 10 layers in total at its deepest.
Another departure from original plans – the deep deadwood of the aft keel has been cropped off by an inch or so (not having a centreline prop-shaft has its compenations); hopefully longitudinal stability wont be affected but it will offer less resistance to turning so perhaps manoeuvreability will be enhanced. I understand the actual F Cs could be a b***h to handle because of the deep deadwood aft.
Cheek plates have been added to each side of the keel, partly to provide a better seal for the diagonal planking along the garboard strake and partly to bring the keel closer to scale thickness. A mahogany strip rubbing strake has been fitted along the length of the keel bottom.
Once all the hull planking was completed I trimmed the topside planks back to the sheer strake in preparation for applying the deck. Decided to skin overall with thin ply and then diagonal-plank (single layer only) as with the original craft (see – I can stick to plans!). I used 1/64 ply pegged in place with trusty cocktail sticks – I drew all the deck supporting members onto the ply so I knew where to pin, as well as regular 45 degree diagonals to aid with the planking. In hindsight I wish that I had (i) spent more time sanding/fairing the various deck beams for the camber and ii) used thicker ply for skinning – the 1/64 took the compound curves of the deck sheer and camber easily but tends to flatten out on the camber between supporting beams; I think 1/32 sheet may have kept the curve of the camber better. Oh well, I'll know for next time.
Plinths for the armaments, deckhouse, deck hatches and other penetrations were applied once the deck was skinned, on the theory that I would plank up to them and not continuously through them.
And that is more or less where I am at the moment – planking the deck with black-card simulated caulking between each diagonal. I am using 1.5 x 5 mm lime stripwood (and yet another pot of Titebond III) which seems to be working well although a lot of sanding will be required to smooth it all out upon completion.
Bearing in mind the whole centre-section of the deck lifts out for access to inside, it means that an individual diagonal of planking on deck can have up to 5 or 6 individual sections, all trying to keep to accurate alignment and to the diagonal. This has been a time-consuming challenge – a single run can take a couple of days to complete given the accuracy needed to butt-up against various plinths (some of which are circular) and glue-drying time for each section (and other aspects of life intruding...)
Some decisions just continue to haunt! Hopefully it will be worth it at the end.
I have completed designing the individual components that will go together to make up the deckhouse; these are still only drawings and I have not yet cut wood for them but I may do at some point soon even if it is just to have a break from planking!
Just as a general remark/question to any that have bothered to read this far – the John Lambert plans on 3 sheets that I am basing this build on shows that the port and starboard sides of the enclosed wheelhouse (not the open bridge) appear to angle in towards the roof panels from roughly half-height of the structure. All the photos of Fairmile Cs that I have examined show the deckhouse to be vertically-sided along its full length. Does anybody out there have any thoughts/insider knowledge on where this discrepancy by John Lambert might have originated? Needless to say as I am a stickler for plans (!) my wheelhouse will have angled sides!
And that is the story to date. Photos follow. Thanks for any interest in this build. Stay safe all.
OSD
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More pics.OSD
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Amazing work, love your attention to detail.
Martin
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Autumn 2022
And at long last I can declare the hull structurally complete!
The deck has been fully planked and the deck edge trimmed back to give a clean line to stick the gun'l rubbing strake to. The chine rubbing strake has been attached and faired. Port holes have been fitted port and starboard and the engine exhaust penetrations fabricated and stuck in.
The propshaft A-frames have been aligned and stuck in (my thanks to steve@modelboatbits for the bespoke frames and a couple of odd-length shafts). A-frames were initially tacked in place from the outside with a hot-glue gun and then liberally epoxied internally to secure in place. The hot-glue was subsequently dug out and more epoxy applied from the outside. The hull penetrations were finally reinforced and then faired with milliput.
The stem shoe was moulded from more milliput, epoxied in place and once hardened, faired and thinned to what looks about right. The hull has been given a single coat of sand and seal but this now needs rubbing back.
The deck planking has been textured by scrubbing it with a wire brush and afterwards staining/weathering the wood to rather satisfying shades of silver-grey by a mix involving strong tea and a solution of steel wool dissolved in white vinegar (which I am sure I read about somewhere on this fine forum). It took a bit of trial and error to get the dilution right, a good job I have loads of spare timber lying around. The stained deck has still to be rubbed down and sealed, which is one of the next jobs on the list.
The engine room deck hatch details have been completed as well as the aft ammunition hatch – thanks to Prime Miniatures for lots of M1 nuts, bolts and washers!
I finally got round to finishing off the design of the deckhouse and the main structure of it has been cut and stuck. The ply sheet has been sheathed in mahogany strip around the outside for a bit of perceived realism. Internal details, wind break, railings and other fixtures and fittings have still to be done. Currently pondering how best to emulate the Kent Clearview screens on the forward windows of the wheelhouse.
The rudders, running hardware and electrics have still got to be installed but I want to get a couple of coats of paint on the hull before I do that, once I have decided on the colour scheme.
So the old girl is getting there, I now just have to get her done before my eyesight and manual dexterity finally desert me altogether! Selection of photos follow.
OSD
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More Photos
OSD
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Absolutely beautiful work :-))
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Spring 2025
How time passes …
With the hull structurally complete, the detail follows. It's amazing how much more time consuming the little things are. Lower portion of the hull has been painted/varnished, black below waterline, dark grey above, but topsides still to do. All paints/varnishes are acrylic. A static float test of the hull showed it to be watertight with an acceptable trim but close to designed waterline, so have to be careful with additional weights from here on.
The electrics have been installed and dry tested – 4 x 2830 1000kv outrunners, outward turning, 60Amp fan-cooled ESCs running off 2 x 7.2V 5000mAh LiPos. XT90 connectors on batteries with Y-lead to two motors, each on XT60 connectors. Motors individually fused. Currently wired for one battery to outboard motors, other battery to inboard motors (but this may change depending on usage characteristics). ESCs configured for outboard motors to start first, inboard kick in at slightly greater throttle. Rudders are split, no mixers on throttle/helm. (Yes, I know this is not conventional Fairmile C configuration, but as said before, my build for my own amusement!). The dry function test of the motors was gratifyingly successful; no blown fuses, no plumes of smoke, no excess heat, practically no vibration even at full throttle ahead and astern. V pleased all round.
Next on the list were the bridge and deck fixtures and fittings. I decided to make as many of them from scratch as possible but some items, like the dinghy, bitts, fairleads, vents and round scuttle hatches were bought-in, although the cowl vents were customised to suit and some of the fairleads modified to reflect roller fairleads.
Bridge furniture was put together from wood and the odd bit of brass tubing. Engine throttles were based on small round buttons and involved lots of bits of brass, some soldering and various coloured pinheads. The flag lockers tried to mimic scale thicknesses of wood used in the partitions and have turned out surprisingly well, just need to fill them with flags now!
On deck, the stemhead fitting was fabricated from brass sections, an articulated CQR anchor built from brass and wood; windlass cobbled together from assorted bits and pieces; accommodation ladder, deck access hatches and various ready-use ammunition lockers made from wood and odd bits of brass (still working on the RU lockers for the 0.5” machine guns). A pair of Carley floats ended up taking a disproportionate time to design and make to as near-scale and realism as practicable, but pleased with the eventual results.
Still to do – hull topsides to paint, stanchions for deck-edge railings to fabricate and fix; windscreens for bridge to make, nav sidelights to make and position, gun stops and all things to do with armaments still to decide upon (scale weaponry courtesy of Battlecrafts), mast and related fittings to find/make/fix and whatever else crops up in the meantime, so a while to go before job done; however I doubt it will ever be 'done', more likely I will just stop working on it! Some photos follow.
OSD
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More pix
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... ah, only 11 years! %)
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It is indeed, beautiful work O0
I had no idea the diagonal deck planking was in a singular direction only
Will keep on watching progress....please keep the images coming along
Derek