I've been working on a pair of model FN5 turrets for an RC Wellington, which are designed to have FPV cameras to take footage from within the turrets in flight, much like what RoboBiggles has done on youtube. The turrets feature:

Fully working pneumatically elevated gun-cradle and guns
Model Brownings with working cocking mechanism and liftable top cover
Fully working miniature collimating Mk III gun-sight with automatic reticule dimming in low light
A spotlight, overhead lamp, 3 Bendix signalling lamps and a "panic-light" - all work.
Ammunition tanks and various chutes for feed of rounds and expended cases and links
600 parts per turret, plus a similar number of M1 machine screws, washers and nuts etc, hand-tapped into the nylon parts. Virtually no glue anywhere.
Provision for servo operated traverse
Fully glazed cupolas with correctly shaped compound curvatures (in progress)
Fully operable rotary ventilators (not yet fitted)
Openable doors with working latching mechanisms
Hand-dyed correctly coloured silk-covered cosmetic wiring
Correct mechanical linkages to slave the gunsight to remain parallel to the guns.

My youtube channel can be found by searching for Fidd88 or via these embedded films:

1st test of elevation mechanism


Collimating gunsight


Film of stills taken during construction


Exhibiting the turrets recently at Brooklands


If you have questions or would like to look into sourcing a kit, or commission turret builds, please don't hesitate to ask.

No words...

This is way to crazy to imagine flying...

hehe, cheers, and thanks for taking the time to reply. There's a load more films on my channel documenting the build, successes and failures. I taught myself CAD and 3d printing at the beginning of the build having not made a model for 40 years. I'm considering making it, in slightly simplified form, as a kit of 3d printed parts, in scales from 1:3 to around 1:6 for RC modellers or model-makers who fancy a different sort of a model. I'm currently working on the cupola windows, so hope to get the vac-forming done once CV19 falls over.

Attached are a load of stills taken during the build. The yellow structure is a rotatable jig, to allow work on any aspect of the fuselage or wing without having to take it out of the workshop to turn it around. The CAD picture of the geodetics shows the changes that need to be made to fabricate this even with small pop-rivets. A prototype shape will be made this year before construction proper of the airframe begins.

And some more recent stills, in black and white

Bloody marvellous!
Are you going to go on and finish the rest of the aircraft now?

As soon as the turrets are complete, they'll be mothballed until the airframe has a few flights under it's belt, with fairings and ballast standing in for the turrets. Before the fuselage can be built, I need to fabricate some test-structures for fatigue and vibration issues. The intention is to build a simple bending machine with a chain of interlocking spacers within the geodetic channel, so that as it's bent, the cross-section can't collapse.

Once all that little lot is squared away, the build proper can commence, probably around the middle of next year. I'm anticipating the fuselage being a fairly rapid build, as there are essentially only two joint types involved in 99% of all the joints, and it's largely rivetted. The wings are rather more complicated, so they'll be built after the fuselage, applying lessons learned during that phase of the build. The wings will separate outboard of the nacelles for transport.

The turrets are predominantly built from 3d printed SLS nylon, and are largely screwed together. This meant a great deal of work hand-tapping threads with M1 and M1.6 taps, but reaped great benefits in that I could back out of a build sequence to an earlier point in the assembly, without having to break apart parts that had been glued; and as the build sequence was so complicated in terms of getting tools onto nuts or machine-screws, this was an absolute lifesaver. It was a lot like building a clock - with 3 foot long screw-drivers!

The eventual aim is to simplify the design of the turret, and offer it as a kit, printed to any scale between around 1:3 and 1:10 or thereabouts for RC modellers to incorporate in their aircraft, but possibly without the driven elevation and lights etc.

When I first saw this thread I just scrolled through the first post and looked at the video stills, didn't read any text. I thought I was looking at the restoration of an actual turret. Amazing work. Welcome to the forum Fidd

Thanks for the welcome. It's been a fascinating project, as virtually no technical drawings of Frazer Nash turrets exist, and book illustrations tend to have errors in the geometry, so whilst they appear to be an assembly drawing, if built as drawn, things collide or do not move properly. This was a particular problem with drawing the cupola, as it needs to appear to be the correct shape, but it's also designed to allow free movement of parts such as the gun-sight sighting bar which only just miss colliding with the underside of the Perspex window panels.

Fortunately, Mark Evans gave me his CAD drawings of some components he'd recovered from wrecked aircraft, which helped enormously, even if I had to change some dimensions to optimise it for fabrication via 3d printing/screws.

I'm also working on an FN4 and FN25 turrets, which James from Newcastle very kindly sent me as .obj drawings. Pics attached. Also pictured is the scale 250lb GP "bomb", which I may develop. It uses a CO2 cannister to blow a cloud of dust and low-energy "debris" in the form of compressed-sponge within the casing, which comes apart on impact once the cannister is punctured. I need to rework this to bring the cannister into the nose, and have it struck from behind by a firing pin which is free to move towards it when the nose is suddenly decelerated by the ground. This will help the C of G and reduce the overall weight.

Welcome Fidd, you're a bloody typical nutter pom aint ya geezer

Your work is stunning mate, i imagine it will end up being quite the hit once you roll out the completed project out. Does it stem from an interest in WW2 aircraft and rc planes or did you just decide you had to have a massive Wimpy that you could call your own?

My father was in the RAF towards the end of the war, hence the interest. He's long since dead, but I still have his notebooks and pre-war books extolling the virtues of the RAF's new aircraft, the Blenheim, Hampden and Wellington. Of these, the Wimpy was his favourite. Like him, I'm something of an amateur self-taught engineer and inventor - for fun really. My aunt still laughs, 80 years on, at the memory of his home-made mains-powered wasp-trap. His experiments extended in July of 1940 aged 17 or so, to making his own gun-powder and devising what nowadays we'd call IED's. In those days it was called "High spirits", and given it was widely thought that Jerry would be invading within weeks, tacitly approved of, until desire out-ran performance, and a particularly enthusiastic bomb was detonated on the family Anderson which set off the local sirens. A collision with authority followed, he and my uncle were adjured "to join-up, before someone gets hurt"!

So, about 7 years ago I was looking into making model Airship, until I discovered why very few have achieved it - and learned of Barnes Wallace's use of geodetics in airship design. That led me to the Wellington. I'm much more interested in replicating the geodetic construction than the flying model, so I've no interest in a balsa model which externally resembles a Wellington, but lots in a miniature one, whether it flies or not; although the intention is for it to fly. So for the last 5 years I've been researching the air-frame, doing tons of CAD drawing on both the airframe and turrets, and building the turrets.

Attached is an early experiment of my father's at grans house in 1940, and one of early drawings relating the known internal bulkhead (silver coloured) dimensions within the Wellington to interpolate the cross-section of the airframe at any given station (wooden appearance) - all 97 of them! This is a first step to defining the required curvatures of each geodetic channel over the shape, the geodetic paths being angled at 45 degrees to both lateral and longitudinal lines.

Causing an explosion in July 1940? I should think "A collision with authority followed" is somewhat of an understatement! Great anecdote though.
Surprised that with his experimental and innovative leanings he didn't get the tap on the shoulder to join one of the 'Funny Outfits' e.g. the GHQ Auxiliary Units. Perhaps he was too young! What did he do in the RAF?

As my uncle related it (he claimed to be "led astray by bad companions!") the magistrate was finding it hard to keep a suitably serious expression as they were officially reprimanded, and as their efforts were wholly in the interests of defending the country should Jerry have got across the Channel, they did have the sympathy of the court, and were spared convictions, if they joined up without delay.

My uncle joined the Royal Armoured Corps, and was part of an independant tank brigade supporting infantry. He fought from D+3 until the end of the war, and survived (I know not how!) commanding Shermans and later Crusader, towing 17 pdr's. (the latter posting to a safer billet after his 3rd bailing-out from a burning Sherman.)

Dad was eventually trained up as a fighter-pilot at 1BFTS Terrel, Texas, and arrived back in Europe just as the war against Germany was in its final throes. He, and hundreds like him, were then slated to join in what everyone thoughts was going be the invasion of Japan, but just before he was sent out, that war finished too! And in '47 he was demobbed, and never flew again until the mid 1950's, when he and a mate from Terrel days hired a light aircraft for a day. It's my considered (and professional) opinion that they must have frightened themselves half to death, as neither of them ever flew again!

As for myself, I took up gliding for fun, obtaining a "Silver C" then did a PPL on powered aircraft, before eventually going going commercial and qualifying as an ATPL/IR QFI rated to teach the commercial flight test syllabus, instructing for some years until a car-accident put-paid to flying. All I'm allowed to fly these days is "into rages"!

So now I potter in the shed all summer, and do CAD work for the project all winter. Yesterday I attached some flanges to the expended case chutes, and reinforcements to the side of same facing the gunner. In both cases it was to widen the apparent width of the chutes which are a little too narrow.

Yep, a whole family of very British nutters! Great read Fidd and that picture is fantastic. I believe the geodetic construction of the wellibag also lead to its great strength, was it because it was a time consuming build time and skilled labour that it didn't factor into more aircraft or was it simply overtaken by more modern building materials/designs?

It's really interesting that you've asked that question. As an amateur engineer and military history nut, I've long had an interest in looking at old technologies, and seeing if they are applicable in new ways to modern problems. My burgeoning knowledge of geodetic aircraft design made me reflect on what it was which killed the technology stone-dead in 1945. Geodetics are a phenomenally efficient solution from an engineering point of view, as they have (roughly speaking) 3/4 of the weight, and 130% of the "usable internal space" of a comparable aircraft type built in semi-monocoque stressed skin fabrication. For a bomber that means greater range, greater speed, more disposable payload, and better defense, as you can more easily take the weight of defensive turrets.

Relative to the 2 other Bomber Command types of circa 1937, the "Hampden" and "Whitely", it out-performed both by a significant amount. It also shared a virtue with the "Hurricane", in that largely unskilled labour could be used to effect repairs of damage to the airframe, whereas stressed-skin aircraft such as the Spitfire (and all other RAF bombers) generally required factory-repairs. This virtue led to both Hurricanes and Wellingtons serving in the theatres far away, where the ability to effect local repairs was important at the end of long supply-lines. Simplicity of design can be a real strategically important consideration. The Sherman and T34 tanks had similar properties. Furthermore, geodetics proved quite excellent at withstanding hits from cannon-armed fighters or flak, that would assuredly have destroyed a stressed-skin aircraft.

I digress. I realised that geodetics were killed by the advent of the jet engine. As the structure flexes, it has to have a flexible covering, ie doped-fabric. Such fabric cannot endure the speeds of jet-aircraft. (Indeed many Wellingtons returned with considerable fabric stripped from fuselages and even tail-planes by diving beyond VNE to get away from being coned by searchlights. So studying this, I eventually twigged that if one considered cargo-carrying "drones", then this "aircraft" type would be ideal for building using wartime geodetics, as it was safely back in the speed range where none of the disadvantages of geodetics arose.
To that end, I devised a method of making carbon-fibre geodetics using a two-part extruded silicone mould, which was encased in a tube of polythene, sealed at both ends, and then infused under vacuum with resin. This was then pinned into place over a 3d form of the required shape, and cured in situ. When demoulded, this gave a very satisfactory cross-section of the wartime geodetic channel, at scale. The results were very encouraging, with 33mm of the carbon-fibre weighing a single gramme. However, the failure rate was too high, and I lacked the experience to solve the issues, furthermore, the moulds I'd made were too stiff - I should have used an aerated silicone extrusion - so I abandoned this method in favour of extruded alloy, which was a safer bet from numerous points of view.

Incidentally, the Wellington required little skilled labour in fabrication. There are 30 or so geodetic "panels" which made up the wings and fuselage. All the members of these were formed from strip alloy, progressively curved and folded on a specialist mechanically programmable machine (Still in service in 1969 making parts for "Concorde"!). Small engineering firms all over the country were shipped basic jigs, into which the correct members were placed and rivetted and bolted together. These panels were then sent to Brooklands, Broughton and Chester, where the finished panels were brought together to build the aircraft. This allowed for a bomber to be assembled in just over 24 hours!

I attach some old pictures of the carbon-fibre geodetic channel I made, sitting on top of actual Wellington geodetics, and a few shewing the principle of the two part mould.

Super interesting stuff, cheers! The problem solving and engineering etc that go into aircraft fascinate me. Seeing them go from a quick sketch or an idea to a flying machine still has me shaking my head sometimes. Even the reverse engineering used in some aircraft, looking at you Russia, is a great subject.

I'm sure you are familiar with this footage Fidd, building a Wimpy in a weekend.

I have seen examples of the geodesic framework in a couple of the quirky little museums around here (Worcestershire)
Stratford Armoury
Wellington Aviation Museum
And Cosford of course.
Fascinating thread; thanks for taking the time to post here.

Very good work there Fidd interesting to see it.

As a young kid when source literature was not so censored, recipes for black powder were quite easy to get a hold of which lead to various experiments in making it and blowing up Airfix kits in the back garden, Ahh those were the days

While out hill walking looking for a wellington that crashed near the north coast of Scotland we came across what was left of it, really only a shallow pool with lots of rusty metal and pieces of geodesic scattered on top of the hill. Seeing the clothing and shoes in the water brought it home that men had lost their lives flying this aircraft.

It is a great pity that there are no flying survivors of the Wellington, so it is with great interest I look forward to seeing yours take to the sky.

It'll be a decade or so before this one flies, I would think, by the time the airframe is all built, wiring looms and servo's and linkages, fuel tanks and pumping system, and half a hundred other things, all built and installed. But for me, it's "the journey rather than the destination" which is fun. There's just a never-ending series of problems to address and overcome - or side-step! - to make progress. I am really looking forwards to moving off the turrets though, as they've taken most of the last 4 years to get to this point, and it'll be fun to return to the airframe side. I'm also working with Mark Evans to produce a replica "sit in" FN5 at 1:1, as a flat-pack kit using IKEA type construction, for museums, so am always busy.

If you're interested, I'll post some more images of aspects of the turret builds, and of course there are loads of films documenting the builds on you-tube simpkly search on "Fidd88".

"I'm no David Lean" I fear, so a lot of them are a little dull, with me pontificating on problems arising or sold. It's been quite a journey so far, learning to use CAD, making .stl files to make 3d prints, learning to tap holes in nylon, braze brass, fit tiny electrical connectors, use an airbrush, rivetting, make silicone moulds, casting, vac-forming, lathe-work... The list of new things learned is never-ending, which is what keeps it interesting, for me at least.

Attached are a few random pictures. The bullets in the feed-chutes were individually made, and linked together underneath so they could be twisted and curved within the chutes before being glued into position - which saved having to draw them in the correct curvature and then print them as a single file.

That last photo gives me a scale reference for how big the whole aircraft will be!

Nice tidy workshop with essential English equipment for making a Brew I espy

Cheers. M1 machine-screws are about 16p each, and I'm always dropping them - hence the green floor, which saves a small fortune in the recovery of "lost screws" nuts and washers! This is something like the 7th workshop I've built over the years, and all are pretty similar. I start by painting everything white, and installing plenty of lights and power-points. Then perforated "peg-board" is put between the vertical runners for shelving brackets over at least 9 feet or so. Shelving is arranged with one side deep at the bottom, decreasing in depth with height (heavy stuff) and one the other way around (light bulky storage). Using pegboard makes the shelves very versatile, as they can be left empty with tools on the peg-board, or stacked with stuff with no tools behind. Over time, needs change, and I've found this a great way to do it.

In the ceiling, the wooden battens athwartships carry long light stuff, and the red-coloured battens each go across one pair of joists only. At one end of the red batten is loose screw, allowing it to move, and the other end has a screw which drops into a hole in a little fitting made of angle iron. This means that the red battens can be folded out of the way to allow really long items into the "joist storage" before being folded back to support them. There's a drop-down bench-cum-drawing-board at the window, which also serves as a welding arc shield to protect the eyes of anyone in the kitchen when I'm welding.

The white board at the end of the bench is removeable, and serves as additional tool storage, but is mainly there to protect all my power-tools from debris from the angle-grinder when used at the vice. The sintered metal debris from grinding is ruinous to electric motors. The only other wrinkle, is that steel items such as the jig, the bar-stools and other obstacles have luminous tape on them, for when I blow the trip welding and am suddenly plunged into Stygian darkness! It's helpful to be able to find one's way to the door without going arse over apex in such circumstances. Other wrinkles are that every thing readily flammable is in a single box near the door, as are the CO2 and foam extinguishers, so I can quickly remove all solvents etc and then fight a fire with my back to the door. A first-aid kit is over the bench.

Not shewn, are 5 boxes screwed to the wall by the extinguishers, each containing 50 drawers, for nuts, bolts, washers, set-screws, machine-screws, carpentry screws etc.

Otherwise it's pretty straight-forwards I think. I'll attach a pictures, in case it gives any of you ideas...

Oh yeah, it'll be huge. It's much easier to build a large RC model than a small one. There's a property known as "scale weight", which is the weight at which a scale model will appear to transit the sky in the same way as a full-size one would. You've all seen small RC aircraft appearing to fly much faster than a full-size model one would. This is because the scale weight is too high, meaning the model has to fly faster to attain the required lift for that weight. The smaller the scale, the more critical becomes, as the scale-weight reduces at a much faster rate than the reduction in scale.

Put another way, if you wish to make an RC model in metal, it needs to be very large, so that a scale-weight is attainable.

Mine will come out at about 15 feet long, with a 19 foot wingspan. The real Wellington's wings are removeable immediately outboard of the nacelles, and mine will likewise come-apart at that point for transport. It'll eventually travel on a custom-made trailer, whilst the main body of the model can sit on its undercart during preparation for flight. The tailplane, fin and rudder will remain permamently attached.

Driving the propellors will be a pair of 9 cylinder radials, likely "Air-en", with suitable 3 bladed props, each developing 17 HP. So it'll be a very large model. The main construction will be geodetics, with a cantilever floating mains-spar, as per the full-size aircraft, but with slightly thicker metal than the thickness required to be scale, and a slightly different cross-section to the geodetic channel. The reasons for this are two-fold, there's a minimum thickness of metal that can be extruded, and the scale thickness is under this value, and secondly, as the bolts and rivets used in construction have to be larger than those at scale, I needed to change (increase) the distance between rivet holes to get everything to fit without introducing weaknesses to the structure. In the coming year, once the turrets are complete, I will be learning to bend the extruded alloy geodetic channel without deforming the cross-section, and then once that's mastered, commence making some test-shapes in rivetted and bolted geodetics for fatigue/max load/vibration tests before committing to building the fuselage.

The eventual aim is to produce a Wellington more or less indistinguishable from the full-size airframe, at or near scale-weight, with cameras to take footage from within at the main crew positions.

At the moment, largely due to CV19, I'm basically stalled on all fronts except CAD.

What a marvelous workshop.

Thanks. I find it's best to design them, rather than allowing them to grow "organically", which usually ends up with a lot of wasted space, muddle and mess. A really useful idea was recovering my father's Teak carpenters bench with a block-board top, edged with strap steel, and the addition of a folding leaf. The void under the rear half of the bench houses strip timber. Loads of lighting/white-painted ceiling and walls, with a moveable LED spot-lamp over the bench equivalent to a 400w spot incandescent. I also use a Dymo tape-printer to label everything on the shelves, or in the plastic "Nesquik" cans over the doors and elsewhere, which make for really useful stackable boxes for tools and mid-sized stuff that would otherwise be a messy and inefficient use of shelf-space. I also built a 12 foot by 8 foot shed in the front garden to take bicycles etc that I didn't want in the workshop, which helps a lot in keeping it all under control.

The front shed was fun to install. I built a wooden frame for the shed to rest on, then took fabric bags run up on the wife's sewing machine to fill with about a pint of ready-made concrete. A little piece of slate was put on top, then the sub-frame, hammered to level, as it sat on around 50 bags of concrete, followed by the shed. The bags were lightly watered, and then just left to take on any more water from being in the open. The result was a shed floor which, 6 years on, is completely level, and firm and dry, whilst preventing the woodwork of the shed or the subframe from resting in standing water and rotting.

The vac-forming has now been done, by a local commercial firm, and I've started cutting-up the first of the 5 "pulls" done in the 1mm polycarbonate. They've also supplied me with a lifetime's supply of the same material in sheet form, which will eventually be used to "glaze" the Wellington 1c's long fuselage windows above the wing, and the large starboard nose window, as well as the bomb-bay and bombardiers lower fuselage windows. I'll eventually need to make a similar mould for the astrodome and aforementioned bombardiers windows, and vac-form those.

Surplus turret pulls will be salted away to replace and damage or degradation of the intial turret glazing.

I love really talented people.

Freakin AMAZING!

Thankyou for the compliment, but I don't regard myself as "talented", so much as "willing to have a go". Everything from making a plaster-backed silicone mould to casting the tool shape in metallised epoxy resin, was all recently learned from you-tube and thence by talking to the purveyors of said resin and silicone so that I thoroughly understood the drill and potential pitfalls. All of it was the first time for me. So "lucky" possibly, but not "talented"! Pictures to follow after I've completed the front turret window panels and bolted them all together. So far I've made all the front panels for the front turret (5 of) Tomorrow I'll make a start on the side and top window panels, again for the front turret, whereafter bolting through the panels can begin.

After a busy two days, the front and front quarter windows for the front turret have been trimmed and fitted from the initial "pull". This involves drilling the holes through the Perspex where the metal tabs on straps will bolt through the 3d printed tabs which are in turn bolted to the stanchions. Very tedious work that's hard on the fingers. As of this evening most of the panels for the front turret are now trimmed and drilled, but here's a couple of pictures taken earlier in the day. With a little luck, the front turret cupola will be completed by Sunday evening.

Yes sir.

That is talent.

The Beeb's "Even without a butter knife, we still have talent" folks will be by soon. (Hide your knives )

Just don't say "machine gun".

After a marathon effort today, the front turret cupola is finished, bar for the ventilators in the quarter right and left window panels, the position of which I need to research. In the cup2.jpg note the 3 M1 machine screws and nuts per attachment. Each nut was started with my cocktail-stick with a blob of blutak, and has to be placed on the thread end, then very gently teased with the stick until the nut starts on the thread, whereafter I can go on in with nut-spinner and jeweller's screw-driver to finish it. Once the cupola is complete, I'll put a little locktite on the exposed threads to prevent the nuts unwinding with vibration. Once the cupolas are completed I'll post some pictures with them on the turrets. The front of each cupola engages with "feet" on the turret assembly, and then is held down at the back by two screws which go down through the cupola and through the alloy plate on which most of the turret mechanism is built.

And the now near complete front turret. Still to add are the front tub for the gunner's feet, and some fittings for the ventilators.

Amazing...

Amazing construction, engineering and detail.
If one didn't have the workshop background and knowledge it was newbuild, for context one would think it was 1:1 genuine article!

Geez! And I have an rc P-38 that I'm worrying about crashing! I wouldn't even want to Taxi THIS thing. It's going to be museum quality, from the looks of it so far.

Hehe. It remains to be seen if the geodetics can survive the vibration of the engines, taxiing, so you have a point! Had some great news last night, the chap who'd kindly offered to print the "tub" for the front-gunner's legs, has now printed and despatched this - many thanks Helimadken! - so I'll finally be able, presently, to complete both turrets and move onto prototyping the metalwork (geodetic channel and fittings).

5 years ago, I thought the turrets would take 5 months!

Out of curiosity, what might people pay for a kit to make this, or have it made - probably to be largely glued together rather than bolted? The reason for this being that the printing costs in nylon - necessary to be able to cut threads with a tap - are enormous. I'm investigating making the parts via injection-moulding so as to be able to make the "kit". Or, put another way, what would any of you be prepared to pay for a completed and painted model, bearing in mind the build time is at least 3 months, and likely more, for further turrets. (These turrets, being effectively prototypes, had much longer assembly times due to all the problems and revisions that needed to be overcome/re-worked.

I hope I'm not being "mercenary" about this, I'm just trying to gauge potential interest..

A film of the nearly complete turrets and thoughts on "window-bashing"

The front turret tub arrived today, and looks encouraging, although it'll need a lot of remedial filling and sanding to be ready for painting. In the meantime, here's a few recent pictures of the now glazed cupolas on both turrets. I'll photograph them next outside, as the lighting wasn't propitious indoors.

Well both the turrets are now complete and salted away until the fuselage is built some years hence. I've made a new film with all new stills and footage taken from within and without, as well as some new narration, Thanks to all here for the kind words and encouragement!

The last few days have been agreeable and busy in the workshop. Owing the scale change (from 1:4.5 to 1:3.7) that came after I'd built the yellow jig (pics above), I've had to extend the central black "datum bar" (a 50mm square hollow section steel tube) and the 4 "measuring bars" (30mm square hollow section steel tubes) all by exactly 300mm. And drill new holes where they attach to the rest of the structure. So lots of arc-welding, grinding and very careful measurements. The job is basically done, and all 5 bars are now longer and true to the originals.

The upshot of all this, is that the finished Wellington, not including the turrets will be exactly 200mm shorter at (4.7m long) than the workshop, meaning the mount for the turrets will need to be made removeable for transport. The length including turrets will come out at circa 5.02m!

Once the jig is square away there are a number of problems to deal with before the 1st extruded geodetic channel can be used to build some test pieces. Initially flat, but later on curved, It's great to be able to potter at completely different problems than those of the turret builds. Pics to follow once the jig is reassembled.

This is the prototypical genius of the British Man in the Shed.

Utterly amazing.

How long is Dart's plane?

Just wondering compared to The length including turrets will come out at circa 5.02m! ??



edit: Oh, and you are gonna need a bigger boat shop!

Thanks. I can't tell you how amazing it is to get such feedback after years in the "shed" bashing away solving problems or making things!

I've now completed the lengthening of the datum and measurement bars on the jig. I still need to mark the datum bar with all the frame positions (all 196 or so of them!) (two lots of 98 staggered) which define where geodetic members on the fuselage meet with the longerons.

The next phase is sourcing the pneumatic rivet-gun for the miniature rivet-gun, and checking that I can get this tool into the geodetic channel as planned during assembly. Once proved, I can then finalise the dimensions and design of the channel, and get a small prototype run of extrusions.

I'm utterly amazed at this but as a Brit I fully understand that we have people like Fidd beavering away in their sheds

I notice that the model is to be flyable which both delights and horrifies me in equal measures. Will you have any safety mechanisms built in to prevent the unthinkable?

As it'll be over 20kg in weight, it comes into a weight category requiring multiple redundancies on the transmitter, receivers, servos, batteries and actuators, to get its permit to fly. So yes, it'll have numerous additional safety measures to prevent a total loss of the airframe. A hard-landing remains a possibility of course, or an engine failure on take-off likewise. The way I look at it, is that if I get 50 flights out of it before it's damaged or written-off, then there's 50 opportunities for getting some footage from within the turrets and airframe. If it does have a hard-landing and suffers damage to the airframe, then relative to other construction techniques the geodetics are reasonably straight-forward to repair, as I should be able to produce replacement geodetic members without difficulty.

The size of the model will be pretty big. At 1:3.7 scale the wingspan comes out at circa 7.1m or 23 feet. The intention is to have the wings separate for transport just outboard of the nacelles, as per the real aircraft. In order for the prop' arc to clear the workshop doors, the airframe will sit in a custom trailer, tilted about 45 degrees about the longitudinal axis, the outboard wings being fitted at the airfield, where the turrets and supporting structure will likewise be fitted. From a design point of view, the larger the model is, the easier it is to make, and the more tolerance for weight there is if it is to appear to fly at the correct speed over the ground. A larger, heavier, aircraft model also has better speed stability and more inertia. So there are lots of reasons to build it large, especially if one is seeking to produce it using the same construction techniques.

Crickey...Darts 7/8ths Bebe replica's wingspan is only 10cm longer!
What an amazing and skillful engineering enterprise.

Hi, mine hasn't been built yet, so it remains to be seen if it turns into skilful engineering or so much scrap aluminium! The coming year should see some simple test shapes made, at which point that particular question may be a little clearer.

Looking fairly skillful so far...

and that's the biggest understatement I've made in a longgggg time.

Cheers. Not much happening at the moment, I've the "lockdown blues" and can't seem to summon the enthusiasm to get cracking just now. Too much time on my hands! Part of this related to the plethora of dependencies in the next stage. But I hope to do so in due course. I need to replace the PC I usually employ for CAD work and lay hands on the miniature rivet-gun before finalising the cross-section of the extruded alloy channel. After that, I need to fabricate some test flat pieces, followed by building the devices and inserts required to curve the channel to a specific curvature, and "notching" each member through 50% of the thickness where they cross with the other. Since writing last, I've figured the notching out. For a long time I was intending to grind these out with an angle grinder, but couldn't get past the problem of this tending to leave a readily crackable surface along the horizontal portion of the notch.

I've now decided to make that a 2 part operation. it'll involve making a carriage for my angle grinder able to move 25 degrees of so either side of the CL of the notch. With a cutting disc, rather than a grinding disc, I can then make two slits through 50% of the channel which taper towards each other, and then I'll simply use a chisel type tool, with curves at either end, to either punch, or be pressed through the metal via something like an adapted bearing press, to make the final cut. This should result in an accurate notch, without the scope for seeding cracks due to use of a grinding wheel.

But first, I need to get a new pc up and running.

Man, you are doing some fabulous work. Way beyond my skill or patience.

Thanks, but I'm sure it's not beyond your skill. When I first started this project, 5 years ago, all my drawings were done with pencil rules and protractors at an old fashioned drawing-board! Since then I've taught myself CAD in Fusion 360, a great free program for (hobby use) which has a very helpful online community. Learning to output designs into .stl files for printing followed, and then discovering that SLS nylon (3d printed) could be readily drilled/hand-tapped and screwed together. (female threads of M3 and above can be printed and then cleaned out with a suitable tap).

After that, as far as the turrets go, it was just a great deal of revisions to get the mechanisms working. The hardest parts were probably getting the rams to lift the gun-cradle properly - my first attempt using home-made electric linear servos didn't work well - so I moved onto pneumatics which worked really nicely. The next problem area was the compound-curved window panels at the front of the turret cupola. I knew from when I was plotting moving parts positions when working on the rams, that there was very little room at all between some moving parts and these window panels, and it took a long time to research how to make them this accurately. I then learned how to make a silicone mould, how to cast it with epoxy resin, to heat-treat same and then fill/polish the resin tool prior to vacuum forming it with thin polycarbonate. Nearly everything in the preceding two paragraphs is stuff I've never done before, all of it was learned during the course of the project.

Which means nearly anyone can do it, it's merely a matter of hammering away at new problems until you work out how best to build what you need.....

Some of us are good at some things...

I have never seen seen OG's gunsmith skills in person, but knowing his attention to detail, I am pretty sure they are at, or above the skill level of many manufacturers.

You sir are a prototype level engineer. Yeah, I know, a little late for the prototype.

Well it's true I don't mind complicated projects. Here is a wire-frame picture of the turret without cupola, one of the traversing ring, and one of the axle area of the gun-cradle. I did not usually work in wireframe for obvious reasons! in the end the traversing ring was slightly simplified by removing 1 of the 3 sets of bearings, and in the light of difficulties wiring the turrets, the master-drawing of it now has much larger internal apertures for concealed wiring.

Stunning work. I wouldn't even know where to start.

You'll laugh, but attached is the product of the first evening's work on the "turret" using CAD. After drawing what my wife called "a lovely flower-pot dear" it was merely a matter of continuous revision from looking at photographs. Learning CAD with Autofusion 360 is reasonably easy, although compound curves are a bit tricky.

I've just finished expanding the jig for the fuselage build and am now getting all my beans in a row for the initial metalwork on test-pieces. It'll be some considerable period of time though before I have much to shew for it.

Hi all,

It's been quite awhile since I last posted. I've finished re-working the rotatable "jig" and lengthening it for the new scale of 1:3.7 (same as the turrets) and correcting some known errors on the master-drawings in case I ever wish to make better turrets. At the same time I'm revising the design of parts of the model which gave great difficulty. Now that's the workshop has turned bitterly cold, I'm hammering the CAD designs for the fittings required to join geodetic channel together, and also the alternating alloy and rubber fittings, which will be threaded onto steel-cable and then used to keep the cross-section of the extruded alloy geodetic channel from collapsing when it's being curved. So there's quite a lot to do. I have also established that the Avdel Micro-rivets riveting tool, will fit into the required gaps, so that's a major head-ache out of the way too. All this is in preparation for finalising the design of the geodetic channel so the extrusion die can be made.

There are three devices that need to be designed and buillt. First is a revised measuring-sled, which measures distance along the jig, and lateral displacement from the centre line. The second is a device to hold and angle-grinder with a cutting disc for the notches in each geodetic member at every crossing of the perpendicular channels. The third is the mechanism for curving the channel to specific curvatures, so that the assembled geodetic channel accurately defines the shape of the tapering fuselage.

So that little lot will keep me busy well into the New-Year. It's exciting to finally be able to move on from the turrets. In the meantime I'm offering one or two new turrets as a commission build, to help finance the next stage of the Wellington. They are necessarily very expensive as the build time alone - some 6-8 months, materials, further vac-forming and around £170 worth of tiny nuts, bolts and machine screws in each turret, needs to be recouped. I doubt many - if any will want one, but it's worth finding out! Ebay item # 184506409292

Further pictures, film and so on as things take shape. Assuming I don't have another turrret to build!

Nice to have a project to occupy one during the new Covid Lockdown restrictions here in England!

True. It look as if we'll be getting another total lock-down before this bloody disease overwhelms hospitals ability to deal with it. Happily I have a great deal of CAD stuff to do on the Wellington, and a small commission to prepare drawings for a 1930's racing aircraft model, so I can beetle away at both of those in the warm whilst the workshop remains as cold as sin during the winter-months, and all other amusements are off the menu due Covid.

What part of the UK are you domiciled may i ask?
Unseasonably mild but rather 'harry breezers' here in rural Worcestershire.

Hi BD-123,

We're a bit to the south of you, North Oxfordshire. I'd invite you over but for Covid. I've an old back-injury - legacy of a very high-speed crash where I was thrown clean out of the vehicle, having slid on ice sideways into a ditch at 70mph - so I really feel the cold/wet. Much progress in recent days on the CAD side, and am also contemplating some major changes in the workshop to get the room I need beside the bench for the curving of the extruded channel. So lots to do. It's about 6 years since I made some preliminary drawings of the geodetics and associated fittings, too long ago, it turns out, to remember all the necessary relative dimensions to get the system to work. So it's back to 'trial and error' for a bit! No matter, I'm getting faster at drawing it all again!

Lots of things coming together now towards the fuselage fabrication. Because of the tooling costs for getting the extrusions done, I simply cannot get this wrong, So the strength of the channel, strength of the geodetic framework built from it, resistance to metal-fatigue, metallurgy, weight and ability to curve the channels without deforming the cross-section unduly, ALL of this has to work/be understood, first time. Hence months of work now, and taking advice before this can move even to the prototyping stage. Sorry there's nothing interesting to shew you.

Maybe nothing interesting to show, but it is still interesting to read about the progress and what you are having to do to get this to fruition.
Many thanks for sharing this project with us.

Hi, apologies for the late reply, but I've only just seen this. Lots been happening this week, preparing the workshop for the next phase. This is being done because I'm still working out some niggles with the rivet supplier, in terms of the tool-head dimensions. Until that's squared away I can't really get on with the CAD side of things for the extrusion and internal fittings for the standard geodetic joints. I'll be doing a film on the latter, as well as the workshop changes, in the coming days.

Basically I've moved the workbench to near the doors, which gives more room to the right of the bench, and put the displaced shelving where the bench previously resided. I also added several square feet of pegboard between the vertical shelf-rails - attached to inch square batten inboard of the rails - so I can hang all my tools above the new bench position. This form of workshop storage is really flexible, as it can be used as tool-hanging space with or without shelving, or just used as shelving. As needs change over the course of a big project like this that flexibility is really handy. Tomorrow I'm moving all the mini-draw boxes full of nuts and bolts etc to the window area, they'll not be in the way of the rotating-jig. There's also a bit of "lighting" revision to do, as the whole lighting set-up was designed for the old bench position. Never thought I'd had to move it! Heigh ho.

So after 10 days of utter chaos, with tools and stuff all over the place, I've now got it back in order, thank God. A long overdue clear-out was done concurrently liberating a good deal of space. The house is still a mess. but the workshop's becoming presentable again! With such a large airframe, in such a small workshop, I have to get a bit "creative" with storage/layout.
I've just put up a new film on youtube, covering the recent changes to the workshop in readiness for commencing metal-work, and a short look at the two types of standard joints on the Wellington airframe.

Hi all,

It's been a good while since I last posted. As the Australians put it, my workshop is "colder than a witch's tit" just now, so I've mainly been inside in the warm, working on the CAD side of the project, specifically producing a final set of drawings of the cross-section of the alloy extrusions of the geodetic members, and then drawings of the 4 different fittings required for the two types of joints which take care of over 95% of the metalwork joints on the airframe. During the course of doing this I sought quotes for producing these fittings via CNC machining, some 13,000 parts in all. I'd budgeted £1000 for this, so was greatly dismayed to recieve two quotes around the £17,000 mark, Ouch! Talking this over with some other chaps in the same racket, it looks as if I'll be sourcing a small number of the more complex and expensive parts, using these with a silicone mould, and then using the wax positives to investment cast batches of the fittings in alloy, filing and drilling them as required after the casting. It'll take a while, but be a HUGE cost saving. Most kindly, one of them has offered me the loan of a small forge. I don't mind doing this as it's always fun to learn a new skill!

I made a new film shewing how the extruded alloy will be curved, and how my miniaturised form of geodetic node (joint) will go together. In theory!

More to follow as things take shape later in the year.

How come you don't work for Elon Musk designing spacecraft?

Seriously. I do so enjoy your amazing work, thanks for sharing it with us.

Hehe, I don't think Mr Musk would be awfully impressed with 1930's technology, but I find it interesting, nor least because the advent of cargo carrying drones has put this engineering solution of geodetics right back in the speed-range where it thrives. I'm in no way trained as an engineer, I used to work on motorcycle engines, so I've a little mechanical common-sense, and a willingness to learn new skills, otherwise this is all new to me too. Not sure Mr Musk would employ me!

! Spent most of today on the PC trying out some alternative shapes and configurations for the V joint sheer fittings - the red and green ones in the film above. As it looks as if these will be cast, and then machined, I replaced all the 2mm and 1.66mm holes for the rivets and machine screws. respectively, to small "dimples" in the surface where I need to drill. The "dimple" should be much easier to mould, and I'll use it like a punched-centre when it comes to drilling them. I also need to design and 3d print a little "steady" into which these fittings can be clamped, with the required holes through the "steady", so that I can drop the drill through the hole onto the work, and get repeatably accurate hole spacing when drilling the shear fitting.

Pics to follow when complete, and of course I'll post a film when the casting gets underway, Things should start happening soon now. The extrusions will be done first, and then if needbe, the internal fittings can be adjusted in dimensions to the reality of the extrusion dimensions, before moulding and casting. That can't occur until lock-down is over in the UK, as I need to borrow a lot of the gear and be shewn how to do it all.

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Fidd, don't sell your self short sir, this is some amazing work. On the hobbyist level it's on the moon.

You might enjoy this guy. He's a trained engineer, but his hands on skills and knowledge are truly amazing to me.

Like you, it's all about attention to detail. Just on a different scale.

I wonder if this bloke has thought through the implications of the cockpit being towards "air-tight", from the point of view of carbon-monoxide getting inside through the firewall. Hope he's got a good detector in there. I got CO poisoning, twice, flying a bloody French built Cessna 150 aerobat, which had a really bloody awful reputation for CO ingress. Happily I was able to open the windows on that in flight, stick my head out and take lungfulls of clean air, whilst landing with some alacrity. The silencer had fallen away from the exhaust manifold. Again!

There's a reason why light aircraft cockpits are not built "air-tight".

Crikey mate you were lucky to be aware of the life-threatening problem!
One reads accounts of the loss of Hawker Typhoon pilots due to CO inhaltion; though I can imagine the suffocating effects were more pronounced and quick with the volume chucked out by the massive Sabre plant!

Got a few mouth fulls of exhaust while racing an inboard hydroplane. It was almost upchuck time. Thankfully it was of short duration.

No, just well trained. I only had a light dose of it, with symptoms of confusion and feeling "disconnected" from what I was doing. I was an AFI at the time holding the UK Basic Commercial Pilots licence, and the perils and symptoms of CO poisoning were taught to us even at that level, pretty extensively, I was later an ATPL/IR and QFI, still teaching on light aircraft, but lads who were going on to take their commercial GFT (included the NFT), Needless to say, I was a positive misery about CO poisoning, and the detectors being present, in good order, and in date, with the students there-after. CO poisoning is not unlike nitrogen narcosis for divers, one of the very first thing you lose, is the capacity for analytical thought such as "why am I feeling like crap?" for example!

The F150 we had was notorious for this fault developing, as so those of us who flew it were very much on the qui vivre for it occurring. There's no strong smell or fumes with it, so it's a bit of an insidious killer, which is why duff gas boilers are so dangerous. That said, cases of it in aviation are fairly rare, especially fatal ones. Anoxia is much more common, as a killer. Normally someone on board twigs and counter-measures taken with CO poisoning. Aside from the mother and father of all migraines after, I suffered no lasting ill-effects, excepting a determination never to experience it again!

Hi all,
It's been quite a while since I last posted. There's nothing much to show for the last few months, but a lot of parts of the project are developing nicely. The cost of using CNC machining to make the small internal fittings for the geodetic joints proved to be beyond my resources, so instead I'll get short runs of them done, without the holes, and cast them in alloy. But I have confirmed I can get a small batch done, sufficient for mould-making purposes. I'm now on the cusp of of ordering the alloy extrusions, which will be in a fairly soft, ductile (stretchable) alloy. Once they've been curved and notched as required, I'll return the lo the extrusion company who can then temper them to a stiffer form.

So, it's taken a few months of CAD, and talking to numerous companies to get to this point, but I now hope this summer to be making un-tempered test-shapes for destructive testing - high vibration environment - to see of the build method can withstand the likely engine vibrations. or not! In other news, I'm am seriously considering making my Mk IC Wellington an early one, still equipped with the F25 "mid-under" ventral turret, so may do some CAD work on that. A decision to build it will be taken right at the end of the build when the actual C of G is known, as the F25 is well aft of the C of G and so a lot will depend on where the airframe plus engines C of G comes out at, as to whether - or not - the F25 model is viable to add from a C of G point of view.

Thanks for the update Fidd.

Looking forward to more pics as you progress.

That's how projects go, eh? Looking forward to seeing the outcome of all the work you're doing now, I'm sure it will be worth the wait, Fidd. :-)

Hi all,
Apologies for the very long interval between posts. I've had some personal issues to deal with which threw a sizeable spanner in the works of this project, however the end of all that is in sight. Mindful of the need to start getting my RC tickets sorted and to get lots of flying experience I started RC flying with a little electric E-flight "Apprentice", which I flew from ab initio for around 100 hours of flight. I had my first and only crash when I'd started flying aerobatics after a prolonged period of circuit-bashing to develop consistent circuit patterns with regard to the wind on the day. The crash occurred because having finished some aerobatics I forgot to change from "high rate" to "low rate" for the landing, and having made a bit of a hash of an approach "went around". The model went suddenly near-vertical and did a "beautiful" power-on spin-entry faster than you can say knife, and hit the ground hard from about 15 feet. A period in the workshop followed attending to a deformed motor-mount and a snapped fuselage just forward of the tail-plane. I've since flown about another 50 hours, with no further frights or prangs. What is becoming apparent is that this is not a model capable of intensive flying, as I've been having issues with the plastic covering of the tail-plane debonding and then fluttering itself to destruction very quickly. One such debond caused elevator flutter which tore away the starboard side of the elevator in seconds, so landed with half an elevator and bits falling off the model in flight. A new and disagreeable experience!

In order to keep up the flying whilst the good weather persists, I've bought a 2nd model, a Hawker Hurricane with a 1450mm wingspan. I chose the Hurricane because of it's inherent stability and forgiving flight characteristics, but primarily because of the wide under-cart, relative to the Spitfire. Retracting wheels will add some interest to flying it. Pic attached of a similar one in flight - mine's on back-order.

As regards the Wellington, I'm still trying to get my beans in a row to solve all outstanding issues to fabricate both straight and curved geodetics and the required internal fittings, the major hurdle currently is not the engineering side, it's the cost of getting the small fittings used in the two joint types made at an acceptable cost. The cheapest I've found so far is £16,000 which is orders of magnitude higher than I'd expected. So that tricky. But I'll keep bashing at it until there's a result.

Cheers,

£16,000

for "small fittings"??

Ouch.

Some good news here. I've been looking at using CNC cut multiple layers of very thin plywood to make a 2d representation of the the geodetics. By making a laminate structures, and temporarily clamping them as they are fitted but before they are glued, I should be able to achieve the twist required as a well as the bend, and then glue them to make the channel under pressure. This gets rid of a great many of the required fittings, and more importantly, the ones which are 3d, as opposed to cut-outs of 2d metal sheet, can be done away with. It also means I don't have to try bending extruded alloy members. It will mean a ton of CAD work, but I'm more au fait with that these days, so it holds less horror than it did when I first went down the rabbit hole of extruded pieces.

The hurricane insignia is now gradually going on, pics to follow.

Hi all,

The Hurricane is now completed, and salted away whilst I purchase the electronics and new Transmitter to work all the flight surfaces and the pan and tilt mechanism for the FPV camera later on. The painting went well, and I was very pleased with the way the 303 Sqn and Polish insignia came out using the stencils I did in CAD which were cut out with peerless service by chatura@expocncondemand.com . This guy was superb in resolving technical problems caused by the very very small and complex stencils, but also would not take any money for the materials that were wasted during the course of making them, right at the bleeding-edge of what is possible to achieve with a CNC driven drag-knife. I cannot recommend him highly enough for stencil work.

I'm gradually getting a little better at making films, now with adding text and doing a narration sound-track independent of the footage. Who says you can't teach an old dog new tricks.

I had a go at using oil-paint to do a "pin-wash" on the panel lines near the engine, to emphasise the metal end of the Hurricane, and also added "chipped paintwork" to all the panels which routinely were removed for servicing or re-arming. All roundels and other lettering/insignia was painted via stencils, and the Dynham Hurricane "stickers" for same consigned to oblivion. The finished paintwork including all insignias is viewable on the film below. The Wellington project remains stalled for now, as I find a cheaper means of producing the internal fittings for the geodetics jounts.




303 Sqn Insignia

Polish National Insignia

Finished Hurricane