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Frazer Nash FN5 gun-turrets


Fidd88
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Crikey, my thanks, that's just made my day! It's nothing most people couldn't do. I taught myself to use Fusion 360 CAD early on, which allowed me to send .stl files to 3dprintuk, who then sent the "bits" back in the post. I then discovered that SLS Nylon, was both dimensionally very accurate, and crucially, could be tapped with threads down to M1 threads, allowing sub-assemblies to be screwed together, rather than glued. This has two benefits, it allowed for more efficient "nesting" of parts, which reduced the cost of printing larger parts, but it also allowed for the reversal of assembly if I got into a jam with the build sequence. This turned out to be vital, as in effect, it was akin to building a real turret, but with "4 foot long" screw-drivers, so tool access was a major consideration in the sequence of the build.

Other than that, building them was fairly straight-forwards, other than making the compound-curved perspex panels for the cupola, to get the true shape of it. The other related problem was learning to draw compound curves in CAD, which was tricky. This meant that certain features such as the chordal brace stiffeners and the ammo feed-chutes were repeatedly drawn until they were got right. I never really managed it with the chordal brace stiffeners - the green structure that goes from the arch to the top of the main supporting silver side-piece of the turret.

Fusion 360 can still be downloaded and learned for free, although with some functionality unavailable. Have a go! It takes around 2 months of practice and working through tutorials to get quick and accurate with it, and maybe another two months to really master compound curves. There's a very helpful set of forums if something defeats you...

If there's anything you want to know more about, just sing out. My Youtube channel which has multiple films documenting the build can be found by searching YT for "Fidd88". I fear I'm no David Lean, and some are pretty dull, being made more to remind me than for public consumption, but some are interesting.

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Hi all,

Lots of recent practice flying my little foam E-flite "Apprentice" - basically a Cessna 150/172 style high-wing monoplane, but with no operable flaps, undercart or variable-pitch prop. It has a wing-span of around 5 feet, and all the modern bells and whistles in the form of gyros, "panic buttons" and so forth that make learning so much easier these days. I've been flying 2-3 times a week, and can fly and land it even in strong gusty wind conditions without breaking anything although once in a while I have to throw an approach away rather than trying to rescue an approach that's gone pear-shaped. This is mainly because the landing patch is only half the size of a tennis-court, with high uncut grass of 3+ feet all around, so "landing long" just isn't an option. It's not unusual to hear a little whisper as the wings ever so lightly brush the tops of the high grass in the undershoot!

Now that I've cracked landings, both into and cross-wind, I'm now conducting low and slow manouevering flights to really work on rudder and aileron coordination and accurate trimming before I start to look around for more complex model. At the moment I'm getting 10-12 minutes a flight, and reckon I should manage 14 minutes before the battery gets to 50%, if I don't hammer the throttle too much.

Brilliant fun, but I need to get back in the workshop!

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  • 2 months later...

Hi all,

The last few weeks have been busy on the RC flying side. I've done over 100 hours on the "Apprentice" with only one crash. I'd been getting more confident and doing aerobatics, and forgot to switch the control-defelection from high-rate to low rate before landing, which would give fine control instead of the rapid inputs required for aeros. I'd made a pig's ear of the approach and so went around in the normal way, however because of the rate still being high, the aircraft went suddenly vertical at about 15 feet, before executing a very pretty power-on spin-entry - and then ploughing into the ground. The engine-mount, fuselage and tail all suffered damage.

After a couple of weeks I've replaced and repaired all the damage, and should be ready to re-maiden it tomorrow. I've also been building a Dynam Hawker Hurricane, which has flaps, retractable undercart, and should presently be able to carry a gimble mounted FPV camera. I'm getting some stencils made to paint all the roundels, (rather that using the stickers) and will be converting the insignia and letters to that of a 303 Sqn example. I've also added yellow prop tips to the 3 bladed prop, and will add "oil-leaks" and other weathering. Pics to follow in due course.

Hur4.thumb.jpg.a11c5bcc4995f1268d8056d982ab80e5.jpg

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  • 5 weeks later...

Yes, I'm a member of the BMFA for my regular RX flying, but also of the LMA as the Wellington project is a much bigger airframe than they deal with, so I'm also a member of the LMA for design scrutineering for that project. We had a phenomenally busy Club Night here, with some 20 pilots turning up for flying - likely one of the last Wed Evenings that'll be flyable until the other side of Winter now, so everyone was having a last flit. I'll still be flying on the weekends, MET permitting.

I need to get on with getting the Hurricane airworthy now, and start learning about FPV flight once I've got the measure of LOS (line of sight) flying the model in the normal way.

This evening I drew up the proper exhaust stacks for the Hurricane - Dynam supplied me with ones for a later marque of Hurricane/Spitfire with the 6 stacks a side, rather than 3 (doubled) with the "fish-tail" end section. Not easy to draw. Pics to follow when printed and fitted. I need to buy a new TX, and a Crossfire unit for extended range, which should make the control connection to the TX bomb-proof at the ranges I'll be flying. It also bumps the video reception range to well over 4km without drop-outs. Being Digital video it lacks the extreme range of the older analogue jobs, but it's not legal to fly FPV beyond line of sight in this country, so much more than 1km isn't needed for this size of model. So my possibly erroneous understanding has established. Probably!

By the by, I came across an very interesting youtube channel of a Texan model-maker, working in metal, who is currently producing a series of model metal-working machines - lathes etc. Amazing stuff, as it all works! I'd love to gave a small watch-maker's lathe/mill but there's no way I can afford it as well as other tools and materials I know I need for the Wellington.

See: 

 

 

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  • 2 weeks later...

So lots of time in the workshop recently re-painting the Hurricane from it's factory colours, with a deeper shade of duck-egg blue and dark earth/dark green with Alclad paints. Still to do is all the insignia which will be airbrushed rather than using the bloody horrible stickers that came with it, before finally applying (after a suitable test on polystyrene) of the Alclad gloss varnish (metal areas of the airframe) and Alclad matt varnish for the "fabric" covered parts. After which the weathering/oil-stains etc can be done.

I've also bit the bullet and purchased a Tx16 transmitter, and will shortly by a crossfire unit for extended range. For now, the kit canopy will be used, but that will be replaced with an optically clear one for FPV flight in the Spring. The proper "Fishtail" exhausts have been 3d printed but are yet to arrive.

Contrast this picture with the stock image above. I think it's an improvement so far!

P1080004

 

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So had an enjoyable 3 flights today with the "Apprentice" after spending the last few days finishing the painting of the 303 Sqn. Nowhere close to your standards for such a big model but like decorating the house the "4 foot rule" applies! (if u can't see a blemish in the paintwork, it's a "pigment of the imagination"! 

 

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Cheers. When I move from line of sight flight to FPV (first person view via real time video transmision from a pannable/tiltable camera, I'll replace the current canopy with a 3d printed one capable of opening in the normal manner, with optically clear window panels. The current one is far from optically clear, and is therefore no good for FPV flight. Many FPV pilots of warbirds simply omit the window panels but keep the superstructure of the canopy. I'd prefer to avoid that if possible.

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  • 1 month later...

Hi all,

Lots happening "behind the scenes" lately. I've been assisting - with advice and some CAD files- a chap modelling an FN5a (lanc nose turret) model in circa 1/6th scale, in the hope he can side-step some of the traps I fell into making mine. Usual problems connected with extant drawings being incorrect geometrically, and lack of plans. If I get his permission, I'll post the results of his work here. Additionally I've bought a Radiomaster TX16s transmitter, and equipped the switches  with pretty colour coded plastic gaiters to make it look as if I know what I'm doing. In truth it's because I'm getting a bit senile and despite my models not needing a tenth of the number of switches with which this beast is equipped, it should reduce the frequency with which I select "undercart up" only to see the nav-lights come on instead, when I have a "senior moment"!

I can't get to grips with programming the transmitter, which by all accounts is less fun than root-canal, owing to the battery being on back order since God was a boy. I am looking forward to that. The clevises on the Hurricane cannot be replaced as those appear to have been lost in transit. Bugger. That's okay though as it's far too windy and generally unflyable, and the workshop, currently, is colder than a witch's tit, so not conducive to spending time there. It has a heater which turns money into noise, but does not appreciably warm it up.

Am still leaning about FPV. Just as I get the hang of it, some new protocol, camera or widget comes out, rendering all previously hard-won insights into this arcane branch of modelling irrelevant, and the incantations begin again! 

Naturally the newly named winter storms have been battering us. Usual attrition of fence-panels, and fun-filled evenings trying to get them back the house from 8 miles away inexpertly lashed-down on the roof-rack at 20mph lest it fly off. God I hate winter. At least this time I had the presence of mind to store it in the workshop, nice and dry, instead of what happened last year when it got wet, swelled and had to be planed to get it to fit in the slots in the concrete posts. Those of you who have had to plane wet wood will understand my reluctance to play that game again any time soon!

It's enough to even make one take up plastic kit modelling, so it is.  🤯

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23 minutes ago, Peterpools said:

Amazing work

Keep 'em comin

Peter

Cheers, nice to hear from you in NY, as a nipper I lived in Westchester County for a few years, at "Waccabuc" - Dad and his legion of unpaid and bonded kids - restored a very large clap-board house from the 1880's, which when we bought it was held together by the holes the wood-worms had left! The name "Pound ridge" rings a bell in that area, is that where you're from?

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  • 4 weeks later...

As the weather isn't flyable just now, I turned to converting the box my TX16S transmitter came with, into a carry-case, using seat-belt material, a hot-glue gun, and cutting up one of the two neck-straps the transmitter the transmitter came with. You can buy "proper" Radiomaster cases, but I prefer mine as it's a bit stronger v crushing loads, but perhaps less protective to being dropped. I shall strive mightily not to drop an hundred and sixty quid transmitter!

It worked well, with the hot-glue gun providing a very strong bond to the seat-belt material, and it looks fairly smart if one can overlook some over-enthusiastic use of said glue-gun!

I've had a crash course in using it, and now have Edge Tx rather than Open Tx loaded, which means all the touch-screen works. Loud cheers!

The Hurricane is stall waiting for a mate to 3d print a part, but has had some additional weathering paint applied, so now looks suitably battered and less "foamy"! Still waiting on a bunch of parts to make the detachable portion of the upper fuselage and cupola. The intention is to make one as suitable for 3rd person flight, and the other for FPV, so I can later elect to alternate between the two modes of flight. One will have PO Pruneski, my plastics pilot figure in the cockpit, the other will have the gimballed camera, and all the perspex cut away to just leave the framework. I may in time detail the cockpit on the FPV one.

Still working on the Wellington geodetics, have now figured out 4 different ways of producing the curved geodetic channel, so now it's a matter of picking the right method, with least risk of failure in flight or manufacture, and what I can afford...

Anyway, that's recent progress. I know all this is moving away from the normal posts here, but I figured I'd keep all my posts in one place! I will come back to the more mainstream modelling in due course, interspersed, I hope with some footage of flight.

 

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