Westland Wasp HAS 1: 1/24th Scale.

[mozart]

Totally gob-smacking!! 

[Anthony in NZ]

I can only echo everyone elses responses to this remarkable project!  I knew when I spent many an hour over those 2 visits for you at the RNZAF Museum that you would do an amazing job....but this beyond what I thought you would do...I truly am speechless and in awe.

 

What CAD programme/software do you use may I ask?

 

Cheers Anthony in awe

[Archimedes]

Wow, having been a design engineer some years ago who spent many thousands of hours on CATIA, Solid Edge and other programmes I have to simply tip my cap to you for the standard of what you are doing on CAD here. Impressed. I second the question: which system are you using to generate the 3D CAD of this aircraft?  I am not a big helicopter fan but you CAD work and the fact that it is the wee Wasp has caught my attention! Well done!

 

Kind regards,

Paul

Edited June 3, 2023 by Archimedes

[TheBaron]

No sooner had I posted the last update on here than I noticed what might be termed a 'techno-historical' error in my designs for the electrical and air system assembly. Such is modelling eh?    More on that in a moment, after the mail....

 

On 6/2/2023 at 1:17 PM, mozart said:

Totally gob-smacking!! 

You're a pal Max, thank-you.

 

On 6/3/2023 at 12:47 AM, Anthony in NZ said:

I can only echo everyone elses responses to this remarkable project!  I knew when I spent many an hour over those 2 visits for you at the RNZAF Museum that you would do an amazing job....but this beyond what I thought you would do...I truly am speechless and in awe.

 

What CAD programme/software do you use may I ask?

 

On 6/3/2023 at 3:42 AM, Archimedes said:

Wow, having been a design engineer some years ago who spent many thousands of hours on CATIA, Solid Edge and other programmes I have to simply tip my cap to you for the standard of what you are doing on CAD here. Impressed. I second the question: which system are you using to generate the 3D CAD of this aircraft?

Anthony & Paul - thank you for your kind words!

 

To answer your question: I've used Fusion 360 for about three years now.

 

After looking around online at that time, its interface and workflow met my needs in terms of that all-important 'look & feel', especially in the relationship between the drawing and modelling functions. Not having any engineering or CAD background also required that whatever solution I adopted didn't require any professional qualifications in those areas to operate on a hobby basis.

 

In terms of the actual design process, experience has taught me you need the design environment and visual references alongside each other at all times, as constantly trying to interpret frequently ambiguous shape information from multiple photographic and lighting conditions in the sources (as well as tying thse in with technical drawings in the maintenance and parts manuals) is a kind of 'human photogrammetry'.

 

This is the setup I currently use on the Wasp:

Fusion on the left, whilst the right hand monitor runs a piece of software called PurRef, which is perfect for creating scalable mosaics of imagery for specific features and  allows you to bounce back and forth between the two. The whole shebang is run by one of these Dell notebooks (something I wouldn't have dreamed of until recently) - the Iris XE chipsets in them are utterly astounding at handling the graphics side. These notebooks are expensive, but you can sometimes find good offers on A-zon in the refurbished section. It's also necessary for having old epsiodes of Danger Man playing on in the background when working of course....

 

I mentioned a screwup at the start of this update, one occasioned by this very evocative period image of XT778 on HMS Ambuscade (the subject of this build):

Image credit: HMS Ambuscade Association.

Tucked on top of that Nimbus engine you can just about make out an angular metal enclosure which houses the electrical and air valve units. Now that installation comes in two versions, the one which I posted in my last update:

and the now historically-correct version for XT778 which I've redone over the weekend:

This involved not only a redesign of the brass PE housing, but as you can see, a lot of re-routing of the extant air pipes and electrical runs( and adding several new ones) had to be done, along with a reconfigured three-way valve unit:

One benefit of this overhaul though was the opportunity to add this utterly steampunk air temperature switch to the top of the enclosure:

For some deeply immature reason I can hear the helicopter making 'Arf Arf' Popeye sounds now....

The now correct ensemble in rendered form:

With any of that pipework and wiring below the ⌀ 0.8mm now to be added at the  assembly stage using wire and/or metal tubing, I also took the precuation of carrying out some tests at the weekend and can confirm that the mounting holes now designed into the various features will work quite happily down to the use of ⌀ 0.3mm wire, as seen here:

(Apologies for the shaky macro shot)

I hope you've had a good day - it's been more Arizona than Ireland here today...

https://youtu.be/aTxg-15TfHg

Tony

 

 

 

 

 

 

 

 

 

Edited June 6, 2023 by TheBaron

[Landrotten Highlander]

Love your set-up as well as the work on the 3D model.  Looking forward to futher updates

[Starfighter]

Brilliant work and a great setup! Regarding the parts I need to have cast in metal, I was thinking of printing them in castable resin and asking a goldsmith whether he'd be able to cast them for me for a reasonable price. I guess the "reasonable price" thing will be the issue... 

 

[TheBaron]

 Hello all, and in what seems to have settled down to a monthly cycle of updates, there's a bit more of significance to report on the Wasp.

 

Mail first though.

On 6/6/2023 at 7:23 PM, Landrotten Highlander said:

Love your set-up as well as the work on the 3D model.  Looking forward to futher updates

Kind of you LH. In the interests of full disclosure I do have to  stress that photo of the studio setup showed it in 'freshly dusted and hoovered for public display' mode. Often there are more cat hairs and coffee rings decorating the place...

On 6/7/2023 at 12:34 PM, Starfighter said:

Brilliant work and a great setup! Regarding the parts I need to have cast in metal, I was thinking of printing them in castable resin and asking a goldsmith whether he'd be able to cast them for me for a reasonable price. I guess the "reasonable price" thing will be the issue... 

 

Many thanks Ben.

 

As a one-off job I agree that 'reasonable price' would be the complicating factor with the costs of casting, firing &etc. Belgium will have many fine craft jewellery studios so it might be worth asking around to see if any of them could incorporate your parts onto a tree of other items they're doing like rings and so forth, thus including it into an existing job rather than as a separate (and more expensive) one. The only issue then would be the metal they're casting in, which unless you want gold or silver legs might mean bronze?

 

Down to business then.

 

Not atypically in modelling, I'd intended to finish off designs for the hydraulic system of the Wasp and move on when closer examiniation of sources revealed a much more significant body of work needed doing up front on the engine deck. It seems blasé to admit to overlooking something this extensive on a subject but it involves an area directly below large conical main rotor gear box, one pretty thoroughly concealed from view on photographs. If I tell you this is one of the clearest images of the area you perhaps get the idea:

Image credit: Ondřej Škarka

As you can see, what isn't obscured by pipework is hidden in shadow. It's even worse to port, where a large hydraulic control box effectively masks everything under there from view. It doesn't help either that a number of existing museum and display airframes have either disconnected or removed those hydraulic parts altogether!

 

I never rely purely on photography these days so in this instance was able to identify hidden features from maintenance drawings. This helped to a great degree yet it's such a complex and confusing arrangement of parts under there that I needed to read up on exactly how the Wasp was controlled via these structures if they were to be rendered faithfully. As is often the case I did up a sketch map to help work out what I was seeing:

I won't bore you with details but a brief summary is that the pilot's inputs via collective and cyclic are fed horizontally back from the cockpit via two distinct control runs which connect to a Z-crank hub. From here the inputs are fed upwards into the conical MRGB casing by two separate control rods, a central control spindle attaching to the spider arms and a separate cyclic pitch control to the piston skirt relayed via an angled control beam.

 

You might at this point in proceedings be questioning the need to put so much effort into understanding concealed detail: a prime motivation was the fact that early on in proceedings I realized how these features would allow me to solve a problem which up until now I hadn't a clue how to address - how to support/brace that conical gearbox and the related main rotor blade structures mounted atop it. The existing diagonal support struts - even at 1/24th scale - were never going to be sufficient for that alone, so here I realized was an opportunity to reverse the logic of the real world and use the vertical control rods (built from brass) as a rigid load bearing support that didn't compromise visual authenticity.

 

Bouyed up by this I first drew out a control grid (to ensure that various components met at the right points in space) and then used this to begin designing the parts in sequence, starting with the port-side bellcrank and servo for cyclic pitch control:

Granted it looks at this point in proceedings more like a medieval siege engine than part of a helicoper, but once the stbd twin is in place:

 - you can hopefully get the idea about how these two features meet at a central bearing to relay the pilot's inputs via the central control spider spindle:

You can also see how that (0.9mmØ) brass rod of that spindle extends down beneath the central bearing into the deck to act as a support pillar for the conical gearbox now. It doesn't do this on the real thing of course but will not be visible in the finished assmebly to interefere with visual fidelity.

 

This is the  pitch control beam (translating the pilot's movements on the collective into rotor adjustments) which attaches to the front of the main rotor gearbox via a diagonal servo:

Even with detailed engineering drawings I had a hard time understanding how this beam was oriented on the engine deck, partly due to the dense overlay of structures obscuring it from various viewing angles but in large part due to a crisis in belief - I just didn't believe what I was seeing. Instead of simply being positioned parallel to the two servos on either side, it angles to port whilst extending backwards to attached to the small hydraulic pump on the rear of the MRGB:

The (0.7mmØ) collective pitch control rod sticking up from the beam does so at angle to enter the conical gearbox and in doing so, now provides a second metal support for the structures above:

You can see below also how additional support and rigidity is created by those PE brackets attached below the gearbox and into which the port and stbd servo rods slot for assembly purposes:

A couple of X-ray shots give a better idea how the gearbox now sits supported on this rigid metal framework:

 

Most pleasingly as a design solution, it hasn't required inventing any false detail to provide this network of supports.

 

One thing you must always anticipate at the design stage are potential problems that can occur later when actually assembling these objects as physical kit, so in this instance I added locating lugs to the underside of the various bellcranks, beams, servos etc. in order to ensure that they can be positioned accurately on the engine deck:

A couple of rendered views to finish with give an idea of just how flimsy the existing support struts around the gearbox would have been without the necessary physical reinforcement provided by the above additions:

 

Thanks for looking in - hopefully I really will have finished off those hydraulics pipes next time! 

 

Tony

 

 

 

 

 

 

 

 

 

 

 

Edited July 2, 2023 by TheBaron

[geedubelyer]

Beautifully written update. What an enjoyable way to pass a few minutes, thank you.

The 3D design work appears to be equally exemplary.

Great stuff, keep it up.

Cheers

[mydesign]

what a great project!

 

and eye for the detail!

 

very special! 

[airscale]

just incredible - I love the mastery of 3D design and the deep level of engineering comprehension you are putting into this

 

pleasure to be a bystander, thanks for posting

 

Peter

[brahman104]

Man this is crazy good!

 

Craig

[wunwinglow]

Phwooar!

[mozart]

Exemplary work in every respect Tony.  In terms of deductive powers Sherlock Holmes has nuthin' on you!! 

[TheBaron]

 Good day/evening everyone; a little more progress to report on the Wasp in terms of the hydraulic system now finished (bar a couple of minor details) after a couple of false starts. Replies first, then the grisly detail:

On 7/2/2023 at 12:07 PM, geedubelyer said:

Beautifully written update. What an enjoyable way to pass a few minutes, thank you.

The 3D design work appears to be equally exemplary.

 

That's most kind of you Guy. I  must confess that this helicopter has had the same effect upon me as letting your eyes adapt to the dark, the longer I stare at it the more detail seems to appear!

On 7/2/2023 at 2:05 PM, mydesign said:

what a great project!

 

and eye for the detail!

 

That's enormously kind of you Meindert. I've just been admiring your Vampires and Venoms: splendid stuff!

On 7/2/2023 at 9:03 PM, airscale said:

just incredible - I love the mastery of 3D design and the deep level of engineering comprehension you are putting into this

 

pleasure to be a bystander, thanks for posting

My pleasure Pete and thanks to you for those kind words.

From someone routinely producing work of your depth and quality that is very heartwarming to hear indeed.

On 7/3/2023 at 4:17 AM, brahman104 said:

Man this is crazy good!

Decent of you Craig. Cheers!

On 7/10/2023 at 9:07 PM, wunwinglow said:

Phwooar!

Proper job Tim.

On 7/11/2023 at 12:22 PM, mozart said:

 In terms of deductive powers Sherlock Holmes has nuthin' on you!! 

   I keep in training Max by watching the series' with Jeremy Brett...

This is the one where he's explaining to Mrs.Hudson the exact formula for mixing EDSG...

I think that episode was called The Case of the Erroneous Quantity of Blue....

 

Having threatened to finish the hydraulic system for the Wasp off on at least one prior occasion I can finally say that it is all but there, though not without a bit of a cognitive wrestling match regarding what in fact goes where.

 

It all stems from this agglomeration lurking to port beside the main rotor gearbox on the real thing:

Having given the feature only a cursory examination in the past it was with some qualms that a careful study from all angles revealed it not to be a simple box-like affair with only a few encrustations to consider but rather an elaborate three-dimensional puzzle, one requiring some simple sketches to work out its essential character in space:

Briefly stated this feature consist of a sheet metal carcase surmounted by a reservoir for hydraulic fluid, with a cylindrical accumulator to the front. Which sounds rather like the world's worst coat of arms when you say it out loud like that.  It gets even worse when you add in all the fittings and fixtures  sprouting forth from it at various angles. In photos there are particular viewpoints where certain details are masked by the cabin or gearbox supports, or even other parts of the hydraulic structure itself, so that you really need the maintenance drawings to hand to compare with what you're seeing. Also of course it's critical that such a prominent feature on that side of the engine deck  be correct in the matters of scale and orientation inaccuracy will scream to the eye.

 

As on any occasion when faced by something complex, it's often best to start simple and add complexity in stages, meaning in this instance, forming the mounting plate detail as an integrated surface detail on the engine deck:

Those locating slots then allow the interlocking sheet metal (PE in the kit) base to be installed securely:

With that eyeballed in for accuracy, you can start adding in the major features such as the cylindrical accumulator to the front:

 -and hydraulic reservoir atop the thing:

I'm going to hollow out that sight level on the rear facing side of the tank to form a small chamber that a coloured fluid can be introduced into and then sealed behind some transparent plastic, mimicking the effect of a fluid level on the real thing. It might seem a bit OTT but at 1/24th any trompe l'oeil painting effects won't I think past muster to give the appearance of a liquid content. Plus it turns the Wasp into a handy sprit level for any shelf it sits upon....

 

With those 'landmark' items in place, smaller details could then be aded to  the inboard:

and outboard sides of the assembly:

Another addition will be to replace the (currently an embossed feature on the side of the metal sheet next to the accumulator) prominent (Mk.14H) pressure gauge with a 3d printed reproduction.

 

At this point I'd begun to realize/shudder at just how many pipes and hoses were invvolved in this part of the Wasp's system, so again just gritted the teeeth and started simple:

 - getting a little bolder with each subsequent addition:

 - until basically you have The Raft of the Medusa sitting before you:

The bulk of those hoses are in fact accounted for by the three cyclic pitch control servos produced in the previous update. Over to starboard was an additional detail  (one which I'd not noticed previously) in the form of a metal bracket supporting the hydraulic hoses as they thread underneath the main gearbox:

The hydraulic system itself is driven by this pump on the lower port side of the main rotor gearbox:

T. L. Ciastula's seminal 1964 article - The Development of the P.531 - contains an outstanding description of how this pump draws power from the main drive shaft via interlocking gears in terms that even this layperson can understand. There's corresponding pump mounted to starboard for the oil system.

 

Some synoptic images to end on which give an idea of how the hydraulic network threads in amongst the existing features of the engine deck:

 

As in previous occasions I'm using 0.3mmØ as the minimum practicable diameter to build things like hoses from later on using jewellery wire and a bending rig:

Thanks for looking in and it's a pleasure receiving comments from such a knowledgable crew.

 

Take care until next time,

Tony

 

 

 

 

 

 

 

 

 

 

 

 

 

 

Edited July 16, 2023 by TheBaron

[mozart]

Oh......my......goodness Tony!  I knew the Irish* were mad, but this..........absolutely stark staring bonkers!  

 

(not politically correct I know but spoken in jest! )  

 

Love looking at your progressive images, it's like watching a good film at the cinema.