Westland Wasp HAS 1: 1/24th Scale.

[Sepp]

Thank you for the information and education - I shall persevere.  

Edited August 21, 2023 by Sepp

[TheBaron]

Evening all.

Pressure was on the Wasp over the last fortnight for two reasons: firstly I discovered almost immediately after my last update on here that I'd made a grievous error with the sponson, and after taking a week to repair that damage, the undercarriage has fought me all the way.

 

In the first case I'd simply gotten the sponsons too high by about 1mm or so. Whilst that doesn't sound like much  - and indeed isn't necessarily all that evident in terms of the overall outlines of the helicopter - when you take into account the fact that front and back sets of  legs have to be level with one another, that error was enough to throw the front set up too high so that the mounting point would miss the lip of the cabin door:

Taking the mounting bolt as the key datum point, the red line above shows the old (wrong) height, the green the now - corrected level. Not that this change actually shows up on the airframe at this point still :

It took about a week of anxious nights to unpick that damage as with the original designs for that section being done about 12 months back, it was a bit like one of those scifi tropes where going back in time to change the past inherently alters the present. In this case, even a minor change in the software timeline led to various destructive 'ripples' running forward through the causal chain and messing things up, sometimes with whole parts of the model disappearing! 

 

Repeatedly. 

 

Dogged perserverance is the only way in such circumstances until the problem yields.

 

Having recovered from the helicopter equivalent of kneeing yourself in the groin I then got on with the undercarriage, starting up at the back due to it providing the clearest set of mounting points by which to triangulate the various features of the u/c with each other and the airframe. Quite early on in this process the underlying 'box-girder' construction of the Wasp became apparent in the way various part of it would emerge from the skin for parts to bolt onto:

One of the features least-amenable to being reproduced in CAD in my view are forged metal parts (due to their often subtle/elusive topology) so the various mounting forks here took an inordinate amount of time to get right:

The front one of the top pair being a particularly gruseome individual to replicate:

I should say that prior to doing these details, I'd laid out a control grid of axes so that the relationship between undercarriage struts and castoring unit were in accordance with reality:

 - as well as a with the help of the Operating Data manual for the helicopter, that things like the centreline for the wheel were offset to the corect extent from the airframe:

This was an odd feature tucked away beneath the overhang of the sponsons:

Couldn't find out what it was for love nor money until - not for the first time - the cutway of the Wasp in the original Flight article from 1964 revealed it to be the the weapon parachute mounting points.

 

In terms of building this as a kit, there is a very real danger of making the undercarriage assembly too complex in terms of getting all the various angles simultaneously correct without some kind of specialized jig, so I wanted something which could be accurately assembled in as few a number of sections as possible - for strength as well as simplicity. In developing a solution for this the girder construction of the original helped to formulate a plan, starting with the lower rear framework mounting upward into slots across the underside:

Once assembled, that assembly process should be invisible:

With that done the  the castoring units and legs then slide into place horizontally as a self-contained unit:

Again, the intention is that the finished assemblage should be strong but seamless when viewed from the side as well underneath:

 

Up at the front I was able to simplfy matters even further with both top and bottom sections unfied to slide into place laterally as a single entity:

That above view incidentally shows why the sponson needed lowering, so that the front top strut meets the lip of the pilot's door sill. The only flaw in this methdology was the way the mounting slot for the front gear runs out to where it will be visible on the underside of the fuselage:

A couple of mounting blanks stuck into place should mask that sleight of hand however:

Standard resin won't be strong enough in my view for printing those u/c units so I'm experimenting with some extra hard resins - will report on practial results next time!

 

At least the designs for those legs are now complete and bear comparison with the real thing:

Overall the shapes are slowly adding up to something Waspalicious in character:

Thanks for looking in and I hope all goes well with your own works.

Tony

 

 

 

 

 

 

 

 

 

 

Edited September 6, 2023 by TheBaron

[LSP_Kevin]

Mindboggling stuff!

 

Kev

[brahman104]

Agreed! This is absolutely incredible! 

 

Craig

[Starfighter]

Absolutely superb to say the least! 

[Derek B]

Staggeringly good technical draughtsmanship Dave, let alone anything else! Well done.

 

Derek

Edited September 14, 2023 by Derek B

[TheBaron]

Perhaps surprisingly for this thread  I have some actual physical objects to show for once. Must be one of those months that has three full moons and a comet or something...

On 9/6/2023 at 10:21 PM, LSP_Kevin said:

Mindboggling stuff!

This stuff is simple compared to folding the washing correctly when putting it away Kev. 

On 9/6/2023 at 10:22 PM, brahman104 said:

Agreed! This is absolutely incredible! 

Craig, you're most kind.

On 9/7/2023 at 9:12 AM, Starfighter said:

Absolutely superb to say the least! 

Cheers Ben. Inspired by your surface work on that ES-3A I managed to get the underside surfaces of the rear section finished here too!

On 9/8/2023 at 11:45 AM, Derek B said:

Staggeringly good technical draughtsmanship dave, let alone anything else! Well done.

Thanks for that Derek.  You're dead right about the extent to which all this depends on drawing - I still find a pencil and paper the most effective method of working out ideas before committing them to pixels and resin.

 

I started by mentioning physical evidence appearring here for once so although it's still early in the proces of finalizing parts and printing procedures, there are a couple of areas of concern that needed committing to resin to work out if my designs were feasible in two critical respects - one of them to do with strength, the other the level of detail which could be reproduced at both 1/24 and 1/32 scales here.

 

 

Taking strength first: in modelling terms at least the characteristic insect-like undercarriage of the Wasp has two critial weak points - where it attaches to the airframe, and the yokes which hold the wheels:

Standard resin was definitely not going to be strong enough to handle this particular job and unlike the blade forks (which I've already cast from aluminium/aluminum on grounds of strength), I didn't relish trying to similarly create these more extensive parts of the helicopter here from metal. This meant researching some of the stronger engineering resins as an alternative -  which can in many cases be eye-watering in price from a hobbyist's perspective. In such situations I  have to say that the bulk of  the resin-comparison sites out there are bloody useless - little more than clickbait repeating company specs minus evidence from the writer(s) about actually using them. I suspect many are simply written by AI for ad revenue rather than to actually help people. Thankfully there are quite a number of expereienced individuals taking the time to post their experiences online and on the basis of a thorough piece of work from Jeremy over at Figure Feedback I lashed some gelt on a bottle of:

Was it any good?

See this exposure test:

About a couple of millimetres or so in thickness and I simply could not break it with my hands; in fact I reckon you'd need to put it in the vice and whack with a hammer to get it to snap. Ignore the poor surface quality on that Xp test above btw - I'd used IPA for cleanup the first time out before reading that ethanol is better for this Hard Tough stuff and have had no problems since.

 

The only thing is that when you print an actual part with the quite translucent blue flavour of this stuff (no I don't know why I went for that colour either...) it intially comes out looking like it's all gone a bit Willy Wonka:

A squirt of acrylic however and normal opacity prevails:

Engineering resins aren't necessarily designed to yield the same level of detail as what might be called 'display' resins, however, everything here down to the individual bolts was well-expressed to the naked eye. Only with the magnifying visor on could you really see that corners and edges appeared not as pin-sharp as you might be used to which  - considering the trade-off for strength - is a balance I'm more than happy with.

 

Print times with it are about 30% longer and cure times under the UV much longer at 30 mins but otherwise there's nothing very complicated about using it.

 

In terms of surface detailing I needed some reassurance that my calculations were right about the size of the several thousand rivets adorning the completed rear section of the airframe:

I needed these to be subtle but present, which at 1/24th scale meant a guesstimate ofsomewhere around height from the surface of 0.15mm. Printing with the Saturn 2 I could have gotten away something slightly less but was taking a gamble on this figure being sufficient for the rivets to survive scaling down for the 1/32 kit:

Tests were therefore run over the last week:

I did two versions of the 1/24th rear section here because I wanted to do a direct comparison between Lychee and Chitubox in terms of the balance between smoothness of curving parts and sharpness of small details. Despite changes in the anti-aliasing functions in Lychee, I still find Chitubox produces a better print. Lychee however still wins hands down when it comes to designing support structures in my view. Or did, until last night I discovered Tango from Voxeldance and was blown away by its support capability. Am curently testing it so will report results in due course.

 

Anyway, back to the actual objects:

Even the snall rivets along the boom ribbing are distinct enough for my tastes without being overdone:

 - whilst features like the fairing around the winglet harmonize quite nicely with the level of detail in the surrounding region:

 

 

Question was, how much of that would survive reduction down from 1/24 to 1/32?

The above image is a good example of one change I need to make to the support designs as you can see from the the curved outer corner of the winglet how I need to make the support structure much stronger in that location.

 

Genuinely, genuinely, surprised though to find that all those details remain visible at the smaller scale. Now that surprise is the product of inexperience on my part at never having to contend with such an issue before, but relieved that the gamble paid off. Some more 1/32 views:

 

The tail-cone also preserved all of the detail at 1/32:

 - however the fairing running along the top is so paper thin at the smaller scale  that I'll have to look at redesigning that aspect of it to make it less fragile:

Clamshell detailing also survived from 1/24 to 1/32:

That's the state of play at present then:

Overall I'm relieved with the how these tests have identified a series of problems which are all fixable.

 

Thanks for looking in,

Tony

 

 

 

 

 

 

Edited September 14, 2023 by TheBaron

[geedubelyer]

Crikey!

This looks magnificent. 

Absolutely cracking job. Well done so far. 

[LSP_Kevin]

Outstanding!

 

Kev

[Starfighter]

I love it, that's some great progress! Regarding slicing software - I use Lychee to create supports, export it as STL and slice with Chitu and I am pretty happy with the results. I have missed the info - or at least I can't find it - but which printer do you use? 

 

[TheBaron]

3 hours ago, Starfighter said:

I love it, that's some great progress! Regarding slicing software - I use Lychee to create supports, export it as STL and slice with Chitu and I am pretty happy with the results. I have missed the info - or at least I can't find it - but which printer do you use? 

Thanks Ben.

 

It looks like we use an identical print setup regarding software - Lychee being great for support design but anti-aliasing results inferior to Chitu. Spent this morning playing with Tango from Vxeldance and highly impressed with its auto-support algorithms so might switch from Lychee to that for print prep. As to printer, I use a Saturn 2.

Edited September 15, 2023 by TheBaron

[Derek B]

Where is the salivating icon when you need it! Words fail me Tony, ultra impressive work and dedication.

 

Derek

[mozart]

Just caught up on this Tony, very very impressed with ALL aspects of what is going into the production of surely THE definitive Wasp model. 

[Anthony in NZ]

Absolutely stunning!  I am totally in awe of this build!

[TheBaron]

Morning all (time-zones may vary...)

A few more test prints and fitting have emerged over the last week so some imagery of progress to follow after the mail.

On 9/14/2023 at 12:56 PM, geedubelyer said:

Crikey!

This looks magnificent. 

Absolutely cracking job. Well done so far

Many thanks! It feels like the build has reached a turning point at last with the first definitive test parts beginning to materialise.

On 9/14/2023 at 1:05 PM, LSP_Kevin said:

Outstanding!

Kind of you as always Kev.

On 9/15/2023 at 4:58 PM, Derek B said:

Where is the salivating icon when you need it! Words fail me Tony, ultra impressive work and dedication.

Much obliged to you for that Derek, saliva and all.... 

On 9/16/2023 at 7:09 AM, mozart said:

Just caught up on this Tony, very very impressed with ALL aspects of what is going into the production of surely THE definitive Wasp model. 

Ta Max. Definitive? Quite possibly, in an already crowded 1/24 field. 

On 9/16/2023 at 8:27 PM, Anthony in NZ said:

Absolutely stunning!  I am totally in awe of this build!

I do believe you've had a not insubstantial hand in this coming into being Anthony. 

 

Last time out I'd been flashing one of my larger parts around which you'll be disturbed to learn I subsequently discovered to be malformed. More precisely, I hadn't supported the leading edge of the 'winglets' (that the rear undercarriage legs attach to) during printing sufficiently and with the large bulk of the airframe dragging up and down in the resin, their profile had curved downwards . The addition of a couple of heavy supports on each side was enough to counteract that drag for the corrected prints:

One issue I'd been sort of ignoring up until now was the sheer proliferation of parts that were being generated whereas in many respects the hardest part of the undertaking was always going to be how they all fit together, in what sequence, and with what level of understandability. If it's just yourself and you know the aircraft then you can problably muddle through but conscious of others wanting copies in various scales, you can't just present people with a forest of resin and PE and an instruction book the size of a Harold Robbins. For regions like the Nimbus engine and the gearboxes at either end of the engine deck I was able to combine a number of hitherto separate elements into printable wholes, without any debts to accuracy:

 

 

 

Using Voxedance's Tango software I was able to generate support networks enabling me to print much more complex integrated parts than I had been able to in Lychee and Chitubox previously. The following prints are all test samples  at 1/24 and 1/32 so haven't been cleaned up to any degree beyond removing the larger supports: please avert your gaze from any messy stubs and mini-support visible as a consequence:

One especially challenging part was the main rotor gear box, along with its array of support pylons:

Now via VDT I was able to print these as self-contained units, including the front servo and pitch control beam tucked away underneath:

Mounting these gearboxes accurately on the engine deck then becomes a much more striaghtforward undertaking at both scales:

 

 

The same economy of means applied here to the reduction gearbox and forest of smaller parts festooning its rear:

Avengines Assembled!

There are so may features having to align simulataneously with one another that I was (finally) able to let out a sigh of relief that the designs were working as a physical entity:

A lot of the time in photographs it's not always easy to tell the difference between 1/24th:

 - and 1/32nd:

Where the difference will kick in of course  is when it gets to detailing all the sundry pipework and electrical harnesses on the engine - in relation to which these things in one of the earlier photographs come into play:

I thought it prudent to crerate a jig to come supplied with the kits in order to enable painting and detailing work to be carried out on the engine in a manner minimizing damage caused through repeated handling:

That's it in summary for now - essentially with the above I needed to know that the designs could be translated into a viable construction sequence as physical parts and this mercifully seems to be the case. Next is a full-up test print of the undercarriage in both scales using eSun's Hard Tough resin. 

 

More in due course,

Tony

 

 

 

 

 

Edited September 22, 2023 by TheBaron