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Westland Wasp HAS 1: 'Ambuscade Flight: XT778'


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More class leading/expanding work, Tony.

 

On 1/13/2023 at 6:05 PM, TheBaron said:

Cheers Kev: I must say the printer is behaving itself in this cold weather, even if I do have to heat the resin up on the stove, like something out of a 19th century railyard....

 

 I confess that for the misc. small bits and bobs I printed at the end of the Hawk build I just been wandering to the unheated garage where the Mars 3 sits with weeks old resin in its tank and fired it off.  Seemed to work fine whatever the temperature.  Maybe the results seemed unaffected cos they were so small they were more or less printed before the printer/resin had time to realise they were being called into action…

 

17 hours ago, TheBaron said:

Finally having a smartphone with a decent macro facility means issuing the obligatory harsh close-up warning

 

Obligatory warning noted and further noted to be unnecessary in a Baron-build.  I was gonna go off on a riff about the efficacy of Elf and Safety and/or Trigger warnings; but prudence (nice girl) has cautioned me that such may, well may not be prudent :whistle:

 

It occurs to me that p’raps BM needs a new section for model engineering; cos this build is surely of that species.  

 

17 hours ago, TheBaron said:

Although I haven't test-fitted the arms for the pitch change spider yet , I'm 98.234% convinced from looking at the printed parts that my idea of a resin 'elbow' at the bottom link joint is a fabulous conceit that will not work. Because of the level of play required when the blade pitch changes as seen above, I'll need to build the spider arms themselves entirely from brass, with a working joint that allows for this level of motion.

 

See?

 

98.234% convinced? So rather beyond reasonable doubt and a really quite strong balance of probabilities then Tony? Just translating into terms the legal mind can cope with. :D  We don’t like to commit to too much specificity in the law….

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7 hours ago, hendie said:

It's just a pity Elegoo haven't got around to developing a metal printer just yet.  (I'm sorely tempted by the Jupiter though)

 

Have you thought of adding brass casting to your ever expanding skill set Tony?

 

I'll throw this out there just because... do you need to have an actual working blade fold mechanism? Or  one version with blades folded and one version with blades spread? And provide both versions in the kit.  Is the hill worth the climb?

Personally speaking I would build one or t'other but I doubt I would ever change the display between the two.

 

 

I admit that I too am at a loss when it comes to the need for that stuff to actually operate.

 

This is certain to become an iconic replica of the dear little Wopsie but it seems to me (hendie too it seems) that you are attempting to turn out a toy which can be played with by the onlookers.

 

I am in the 'a version of each configuration' corner my self and think you might be better occupied considering whether to include 'Forth Road Bridge' clamps already fitted to the folded blade configuration blades.

 

4531378205a.jpg

 

Just a thought...

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I'm liking the look of those main rotorblades and the the root. Re Alan's (Hendie's) comment re metal printing and brass casting. If you have a local silversmith, you might be able to get those parts cast in silver. It's not an expensive metal and the lost wax casting shouldn't be either. It might be a solution to more rigid and stronger parts.

As to a 1/32nd copy, my preferred scale is 1/48th, but then my are could be twisted! I suppose it would look good alongside my Revell, 32nd Alouette II, that is once I complete it!

 

Colin

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I have a Tiranti Centricast casting machine, for white metal/pewter casting.  Tony is welcome to come down to Somerset and make use of it for any metal casting.

 

cheers,
Mike

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Quick update today on revisions and additions based on the initial test print.

On 20/01/2023 at 15:15, giemme said:

Almost time for some paint, is it?

:rofl:Almost tempted me to get out the airbrush to prove you correct Giorgio!

In fact I had rather an alarming paint-related experience during the week in fact when my old compressor - quite literally - blew up in the studio! Sounding like a gunshot followed by demented hissing from under the bench it scared the bejayzus out of me: the culprit a tiny corroded hole by one of the leg welds on the tank.

 

Being almost as as expensive to buy a replacement tank as to get a whole new compressor outfit,  I managed to pick up a deal on one of these Airgoo jobs as a replacement.

On 20/01/2023 at 20:15, Pete in Lincs said:

Some very erudite thinking on the theme of strength going on. 

Kind of you Pete: when curiosity drives you into unfamiliar and challenging circumstances on a build is when it feels most worthwhile.

There are no discoveries to be had in following convention...in spacecraft as in all things! 😁

On 21/01/2023 at 01:51, hendie said:

It's just a pity Elegoo haven't got around to developing a metal printer just yet. 

Don't tease you wicked man! 😁

On 21/01/2023 at 01:51, hendie said:

I'll throw this out there just because... do you need to have an actual working blade fold mechanism?

No, of course there's no need. 😁 I'm simply enjoying the challenge and discipline of being able to express things at 1/24 which simply wouldn't be possible to attempt on a more diminutive basis. I follow a number of Japanese modellers via social media who produce work of such intricate beauty in terms of working features that I can only ever hope to produce a pale imitation here. The playfulness and invention they bring to their work just makes you want to smile out loud.

 

An actual kit version of the Wasp at 1/32 won't allow such things of course, so a two-version assembly for the rotors/hub hub is, as you say, the most natural route to follow on that particular occasion.

 

On 21/01/2023 at 02:13, Pete in Lincs said:

Blade folding always brightened up a dull afternoon for me.

:rofl:This made me laugh out loud for no readily explainable reason Pete! There's a Spike M. sketch there I'm sure....

On 21/01/2023 at 08:42, Fritag said:

I confess that for the misc. small bits and bobs I printed at the end of the Hawk build I just been wandering to the unheated garage where the Mars 3 sits with weeks old resin in its tank and fired it off.  Seemed to work fine whatever the temperature.  Maybe the results seemed unaffected cos they were so small they were more or less printed before the printer/resin had time to realise they were being called into action…

You know you've got my attention in a big way at that Steve. :nodding: I have some small bits to put on in the week so I'm doing to try a low-temp. test along the lines you outline there:  much apprecaiate the info. 

I certainly recall having problems printing the Vixen fuselage in the very early days with cold resin which was why I've been paranooid about temperature ever since - that said though, I could just as easily have forgotten to shake the bottle before use...

On 21/01/2023 at 08:42, Fritag said:

So rather beyond reasonable doubt and a really quite strong balance of probabilities then Tony?

You're going to bill me for that, aren't you? :laugh:

2 hours ago, heloman1 said:

I'm liking the look of those main rotorblades and the the root. 

That's most kind of you Colin. :thumbsup2: As a rotary novice (no way in heck am I going to use the word 'virgin' with this audience 😁) it's been quite a learning experience coming to understand (in even the simplest of terms) what the various part up there are and how they function together.

On 21/01/2023 at 01:51, hendie said:

Have you thought of adding brass casting to your ever expanding skill set Tony?

2 hours ago, heloman1 said:

 Re Alan's (Hendie's) comment re metal printing and brass casting. If you have a local silversmith, you might be able to get those parts cast in silver. It's not an expensive metal and the lost wax casting shouldn't be either. It might be a solution to more rigid and stronger parts.

Alan and Colin: I don't know whether to bless or curse the pair of you but I am going to seriously investigate this possibility. Sincere :thanks:

2 hours ago, heloman1 said:

As to a 1/32nd copy, my preferred scale is 1/48th, but then my are could be twisted!

You meant 'arm' there Colin and not that there's an 's' missing....? 😁

 

Amendments to print designs then.

 

In terms of the cabin, nose and roof area, I gavee some thought to the related issues of print strength/warping and breakdown of parts for printing. In the first instance, where there had been buckling issues with cabin floor and underside, after thickening both features by 0.5mm I followed the basic box-girder layout of the actual Wasp by adding x3 longitudinal beams under the cabin:

52641921521_0e7b338d4a_b.jpg

In terms of printing, instead of the combined mass of the cabin/roof/nose (incorporating the extensive yet delicate roof sill) I'm going to break this region of the Wasp down into two main components for printing, first the crew accomodation floor and underside as a single unit, with door pillars:

52642393613_6054a85727_b.jpg

Complementing this is a combined nose/roof section:

52641409252_18d2c24569_b.jpg

This only produces a single seam line to deal with during assembly where nose and undesride slot together, whilst leaving maximum unobstructed room for supports and resin-flow through the structures during printing. It's not  evident in the above shot that I also strengthened all the roof framing around the top by increasing the diameter of the tubular endoskeleton around the inside of it by 25%:

52642393588_b8c65eee0d_b.jpg

This doesn't affect external appearances but does give a much needed increase in rigidity for the glazing to be applied in particular.

 

Thinking ahead to any strain on the combined structure when this thing is sitting on its undercariage at the end, I wasn't happy with the minimal 'tongue and groove' slot I'd previously rigged as a way of joining the cabin rear to the engine deck. This has been improved by continuing those longitudinal beams backward from the cabin, piercing the front wall of the deck and emerging into the region where the autopilot gear and pitch control rods normally sit on the real thing:

img

Mounted on the the reverse face of the cabin wall, that plate above the beams should trap them against the floor, helping resist any strain on the join between cabin and deck when sitting out on her pins:

52642357130_49b01894d1_b.jpg

Satisfied from having a physical print of the main blades in my hands that the trailing edge was going to be up to the job, I added in the two trimming tabs, to be made from PE on grounds of thinness:

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Not feasible to slot the brassware into the trailing edges, so I've cuts slots into the blades for the tabs to sit into:

52641409262_c55612c5b0_b.jpg

Also revised in Lychee, prints for the revised hub/link/extension assemblies incorporating changes shown in the previous update:

52642176849_ec0b18691b_b.jpg

I'll give that a low-temperature print as Steve suggests, to compare against the initial batch done in the mid 20°C s....

 

Looking back that wasn't such a quick update. Sorry,  I lose track....

 

Take care of ypourselves until the next one.

:bye:

Tony

 

Update: this came in as I was about to post:

28 minutes ago, bootneck said:

I have a Tiranti Centricast casting machine, for white metal/pewter casting.  Tony is welcome to come down to Somerset and make use of it for any metal casting.

Madre de Dios but that's awesomely generous of you Mike! Betwen Alan and Colin's suggestion and now this I have some serious investigation to do. Thank you so much - I shall certainly be in touch!

 

 

 

 

 

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In my capacity as Annoyance Incorporated that offer of Mike's might make it a good idea to replace the link here

52638214116_cdfe91ce05_b.jpg

 

With a modified piece so, in white metal

 

hinge-link.png

 

Apologies for annoyingly unsusphistickated drawring based on your exquisite renderings Tony, but really only trying to help a tad.

 

 

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Personally speaking, I'm not a great fan of white metal. It's not much stronger than plastic unless its a big and chunky piece, and that's not what you are trying to do here.  I would investigate brass or aluminum casting and would you believe there are Metal casting kits for around $120 on Amazon.

 

 

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12 hours ago, hendie said:

I would investigate brass or aluminum casting and would you believe there are Metal casting kits for around $120 on Amazon.

 

 

Stop teasing the guy, will you? Next thing you know, he'll be assembling his own Nuclear Power Plant to cope with all the needs from his multiple advanced modelling tools.... :D  :D  

 

Smart design of the cabin there, Tony! :clap:  :clap: 

 

Ciao

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Lovely work on the cabin area Tony. Writing that got me thinking (dangerous stuff), that we aren't calling it a cockpit. I guess that's cos it's not just a cockpit but a place for other people to be entertained?

 

Coat time perhaps..........

 

Terry

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I've just finished reading Harrier 809 by Rowland White. Fascinating, and a 'must read again' type book. HMS Ambuscade gets a mention too!

30th of May 1982 and Argentina has just one Exocet missile left. Their Radar and Radio operators in Stanley think they have the Carriers location at last.

A pair of Super Etendards launch on a last desperate mission in order to stymie the hated Harriers by denying them at least one carrier.

As it happens the data was wrong by 20 or 30 miles. The missile was launched but got bamboozled by chaff & decoys fired by the escort ships.

It eventually ran out of fuel and crashed into the sea. Just 7 miles off the bow of Ambuscade. Oh and yes, The SuE's got back home safely.

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On 04/01/2023 at 13:11, TheBaron said:

1. Are naval helicopter pilots a breed apart?

 

They complain about the crabs a lot but whine less than Sea Harrier pilots (whats the difference between a Sea Harrier and it's pilot, the Sea Harrier stops whining once its shut down!)

 

On 10/01/2023 at 22:23, Ex-FAAWAFU said:

Addendum re aerodynamics.  I said that the horizontal stab was there to help control the attitude in forward flight, which is true - but I then said some kind of nonsense about comfort.  Their Lordships were never prone to investing much money in the comfort of us intrepid aviators; the reason for controlling attitude within certain limits is far more likely to have been to provide a stable weapon platform, able to drop a Mk.44 (when designed) or Mk.46 (later in Wopsie life) torpedo within a sensible launch envelope, thus minimising the chances of the weapon failing or even breaking up after entering the water badly.

 

That would suggest that the stab was optimised to provide stability at c.90 kts, was which the standard weapon release speed for the Wasp (from 400’, to give them 200’ vertical separation from the Sea Kings).  Lynx the same, only 120 kts.

 

Correct, the stabiliser provides downforce and longitudinal stability, it also offloads some of the work from the main rotor in forward flight. Without it, the aircraft would want to pitch forward, hence aft cyclic - the stab reduces the aft cyclic required.

 

On 21/01/2023 at 08:42, Fritag said:

I confess that for the misc. small bits and bobs I printed at the end of the Hawk build I just been wandering to the unheated garage where the Mars 3 sits with weeks old resin in its tank and fired it off.  Seemed to work fine whatever the temperature.  Maybe the results seemed unaffected cos they were so small they were more or less printed before the printer/resin had time to realise they were being called into action…

 

Here's my 3D printing in cold garage fix

 

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  • 4 weeks later...

Well that was a catch up and a half. Seems to be going rather well Tony old chum. You’ve got details on yer details. Prints are looking splendid too. Did someone say paint? Can you do a yellow one just for me. 😉

 

Hope you’re keeping well. 
 

Johnny. 

 

 

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  • 3 months later...

Morning all.

That's the Introduction finished then.

 

Chapter 1.

Despite all that appearances might conspire to suggest, work has in fact continued on designs for the Wasp over the past months and weeks, though out of a range of circumstances, two quite specific modelling factors have impacted upon the rate of progress. 

 

The first of these factors stems directly from having received a couple of requests from individuals elsewhere on the web wanting to purchase copies of this kit in 1/24th scale (aside from a 1/32nd version already promised here), such an issue necessarily requiring some earlier design decisions relating to the tail and cabin areas be re-examined from the point if view of somebody else having to manageably build one. Secondly, there was also the non-trivial question of having to build the means to vacuum-cast aluminium parts. I'll come back to the latter process later - it makes more sense I think to report on how the work has changed chronologically in the interim.

 

Some time back I'd planned on leaving the aircraft skin 'clean' of rivets here, said features being added later using Archer's rivets in emulation of @Ex-FAAWAFU's glorious Sea King fantasia of legend.

 

This notion has been summarily sent to feed the dust.

 

Although Archer's have ceased trading but with Quinta apparently stepping in with a far more affordable alternative set of rivet layouts, the anticipated complexity of these designs in final kit form (as well as the expense of someone having to buy that many rivets to add as aftermarket) didn't strike me as a fair bargain to the Wasp-hungry, so felt I felt obliged to add these to the airframe myself as part of the printed detailing.

 

Sanity be damned.

 

Only the tailcone and boom have received such treatment so far, to whit the results of several thousand purgatorially-produced rivets now visible along the flanks:

52795744724_97ef774fc1_b.jpg

The asymmetic arrangement of maintenance access panels (the preponderance of these being along the port side) rendered this a much more prolonged task than simply creating the rivet formations on one side of the aircraft and subsequently mirroring them across to the other:

52795897190_6c45faa2de_b.jpg

Quite how much of that will be visible under BlueGrey in all but the most oblique of lights only time and pigment will tell of course - here's the somewhat more straightforward starboard side by contrast:

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With a tailcone able to be open or shut:

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There is another<collective noun> of rivets arrayed on the opposing faces of those sections that again were delightfully non-identical enough to stop you just mirroring the patterns from one side to the other:

52794937222_e1c4792f88_c.jpg

With a rather intimidating number of parts already in the design library, it made sense to actually finish off the rear of the aircraft before procedding forward again to the Nimbus and engine deck (lest crucial details get overlooked) so I set to work on the tailplane and rotor. With these two features at right angles to each other back there, any errors in one would be magnified by the other, so having @Anthony in NZ's measurements of such features cross-referenced with leading particulars in the maintenance manual meant being able to lay out the required dimensions with confidence in advance of creating the parts themselves:

52819319695_c5b72bb45f_b.jpg

Not of course forgetting to check that said windmill doesn't meet the bigger one at the front in an unholy shattering of rotor blades and dreams...

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Much like cleaning a child's face, one you start adding rivets to one bit, of course you have to do the rest:

52818348517_b2ffc10bba_b.jpg

Conforming to that modelling maxim that 'from afar 'tis fair, in proximity, is far from', the tail rotor had a surprising number of complex shaping tasks required to get the hub and blade mounts right:

52819358183_9801376373_b.jpg

In printing terms that will I think need to be produced as three seperate parts in order to avoid  'support-acne' bedevelling those nice smooth surfaces. To wrap up this section then, renders of the finished tail assembly:

52819099929_20c1e14ca0_b.jpg

 

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At the start of this update I mentioned the need to learn certain aspects of metal casting for this build. The two specific areas of the main rotor assembly requiring metal parts are outlined here:

52931426391_059bb52a56_b.jpg

As you can see, the two weak points concerned are the forks where they actually grip the blades, and the pitch change arms (inverted 'C' shaped features attached to the rear of the blade extension and the arms of the spider arriving to meet it from below). For the combination of strength and lightness it had to be aluminium/aluminum ('the Transatlantic metal') used in this instance.

 

All well and good of course but I had to learn to do lost wax casting to achieve this, and, as the expense of buying kilns and furnaces was out, that also meant I had to build the means to cast myself (along with the inevitable experimentation with materials which such processes always require). I won't belabour the details here (though if anyone would find it useful for me to post details over in the 'techniques' section I'm perfectly happy to bore you to tears at great length there 🤣) but after several weeks I had a working gas furnace recycled out an old Calor cylinder with its middle section removed to reduce it to the required interior volume for the kind of casting jobs I needed to do:

52929720864_3e00dfae67_b.jpg

Despite the Heath Robinson nature of the undertaking, 'Old Hades' here reliably gets to over 800°C - well in excess for what aluminium casting requires.

 

Gravity-fed casting alone though proved incapable of getting molten metal down into the finer parts of the pattern so I additionally had to learn to use vacuum casting processes as well in order to force the metal in to the required extent. To do this a cheap pump/chamber combination sufficed, which I drilled out and added some new parts to so that it could function as both vacuum chamber (for the investment) and vacuum table (for the metal pour).

 

The results of this marriage between hope and instinct payed-off with a blade extension and pitch arm of the required material strength for the job:

52929546575_cf806632a7_b.jpg

 

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The surfaces of that first fully-successful cast still suffered from some gas porosity as you can see above, however such experiences have proven invaluable in giving me the means to now produce such pieces in volume with a much higher surface quality when fresh out of the furnace:

52929953685_e474d70a60_b.jpg

A light sand and a polish should bring those up to requirement in due course.

 

That's it for this instalment.

 

Thanks for reading as always - there's a lot more CAD work to show in relation to the Nimbus and engine deck where the fuel and oil systems are now almost complete and the hydraulics have been started on. Again I've made some changes to the engine detailing/structure to account for others having to build copies themselves, so more on that next time as well.

 

Until then,

:bye:

Tony

 

 

 

 

 

 

 

 

 

 

 

 

 

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Glad to see you back Tony and a very interesting update to celebrate with.  The metal castings look great.  That's a skill not often needed, but when it is, there's really no alternative unless you want to invest in a rather expensive CNC machine.

 

Isn't the collective noun for rivets a Shackleton ?

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Welcome back Tony!

And what a return. Not only exquisite rivetry, but also a whole new skill set. I have no clue how you figured out how to make all that equipment, and since I have no intention of copying you, it doesn't really matter anyway. Still enormously impressive, both the new equipment and the parts extracted from it!

 

Ian 

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:yahoo: He's back! And at full steam (pun intended) already! :thumbsup:

 

Metal casting, uh? Now, if only 3D printers for metal alloys were more affordable.... :D  :D

 

 

Welcome back, Tony!

 

Ciao

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