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Westland Lynx HAS.2; Airfix 1/48 - converted
Topic Started: Jul 4 2018, 11:37 AM (205 Views)
Nikon User
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UPDATE 3


Time for more modifications. There are enough to keep me busy for a while. :WHIP :WHIP :WHIP

The horizontal stabiliser supplied with the kit is the short version, complete with the Gurney Flap. For the HAS.2 helicopter I need to file off the Gurney Flap (shown sticking up at the trailing edge) and lengthen the unit by adding a section of plastic.

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Two pieces of plastic were bonded to achieve the correct thickness for the leading edge of the stabiliser

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A straight edge was cut and the new plastic bonded to the kit supplied stabiliser. This photo shows my new stabiliser cut to the correct length with the sanding started, to give the correct aerofoil profile.

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The main engine cover needed some work to remove the aft section of the top air intake and exhaust scoop on each side. This photo shows the port side done, and the starboard side section to be removed marked in red. At the bottom of the cover is the rather fierce and prominent moulding seam left by Airfix when the kit was produced - this must be removed on both sides!

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Here's a test fitting of the engine and transmission covers. With the 1/48 Airfix Lynx, there are different combinations of some of these parts, depending on which version of Lynx you're building.
Test fitting is a good thing!
:whistle

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Test fitting of the partially painted cabin module

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Another two areas to fill flush with the aft fuselage surface are the square recesses for the Orange Crop ESM antennae

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The cabin and fuselage halves are now closed up

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The build is going well up to now, but sooner or later, the tail rotor is waiting to ruin my day/week.


More soon.

Regards,

Nigel

:grin:





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Olde Farte
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Lt. Derek 'Smurfy' Reeve
After all this work Nigel the tail rotor will be a doddle.
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UPDATE 4

The sponson and main blades are receiving attention this time.


The kit sponson has angular tips, where I need the smoother bullet shaped fairings for my HAS.2 I cut away some fairly large chunks of plastic and then used the tip & tail from a fuel tank out of the spares box to graft on to make the rear bullet fairings. In this photo you can see I've started to cut away plastic at the top, and see the portion of the fuel tank I'll be using. It took a lot of sanding and shaping to achieve the required profile.

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With the left side done, I now had to make the right side look the same - :WHIP

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The sponson, nose cone and upper deck fairings were fitted - it's starting to look like a Lynx!

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Please believe me when I say I could bore anyone half to death on the subject of Lynx aerodynamics. I'm not pretending to be an expert by any means, but I find it a fascinating subject. Here, I'll try to refrain from my favourite topic, and just say that the Lynx has had two types of main rotor blade fitted - one with paddles and one without. I need the straight version, so the paddles were cut off.

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Airfix supply two sets of main blades in their kit, so there's plenty of plastic to use to create new tips. My method is to cut the paddles off at about 45 degrees, to give a decent contact area for the new tips. The leading edge of the main blade needs to be 103mm long. I tape the large blade section to a metal ruler, with the leading edge root 103mm from the end of the ruler. That tells me what the new section needs to look like. I size the new plastic on top of the main blade, marking the angle to cut with a pen. Using this method, the angle isn't critical, and can be slightly different on each blade.

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Once cut and sanded, the new blade is taped firmly down and clamped, to be left overnight. As there's room at the other end of the ruler, it seemed rude not to do the same there, so two blades can be modified at once.

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With one end of the blades sorted, attention turned to the blade roots. With the earlier blade, the root profile was deeper. Westlands made it more shallow on the later blade, so I needed to create and add a fillet.
Cut from plastic card and bonded on, filler was applied and they were left overnight to cure. Lots of sanding was then done to reduce the card to the correct blade profile. Lots & lots of sanding... :whistle

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The end result - four finished main rotor blades :party

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I'm not sure what's next, but I'll post an update in a few days. I'm really enjoying this build!

Regards,

Nigel
:grin:
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Olde Farte
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Lt. Derek 'Smurfy' Reeve
So are we Nigel.........................
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mac1677
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Lt Mac 'Shocker' McSheffrey
Cracking build Nigel, great modifications :cool
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Jonesy113
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Nick 'Token' Jones
This is great to watch, always wanted to do some scratch building but don’t have the confidence (or skills) to try it. :clap: :cool
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Jonesy113
Jul 15 2018, 08:31 AM
This is great to watch, always wanted to do some scratch building but don’t have the confidence (or skills) to try it. :clap: :cool
I think with scratch building and modification, one barrier for me has been the price I've paid for a kit. With an expensive kit, I can't get over the thought that I could write off the kit if it goes wrong. With a cheaper kit, it doesn't hurt so much.
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UPDATE 5

There's light at the end of the tunnel now. Most of the changes to the model have been done, so a little more assembly is in order.

The windscreen and roof panel section was added. On the 1/48 Lynx kit, this has always proved to be a good fit in my experience.

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The forward doors needed a little sanding to be a good fit. The cabin doors and tail boom were also fitted. The tail boom join is good as long as it's paint free!

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The model is now ready for some primer, which will show areas needing more filling and/or sanding :redface

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Right side in primer - it's my favourite Halfords Grey aerosol

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Left side in primer

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The remaining jobs are down to;

Undercarriage fitting
Aerials, probes, Harpoon and cargo hook to be fitted
Horizontal stabiliser to be fitted
Main blades to be painted and assembled - no droop allowed!!!
Tail rotor to be modified, painted and fitted
Final top coats to be airbrushed


As mentioned before, there's light at the end of the tunnel. More soon.

Regards,

Nigel
:grin:




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Mark M
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Hawk T1
this should be a book - the how to guide, cracking mate
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Olde Farte
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Lt. Derek 'Smurfy' Reeve
Looking better now she has some foundation on to cover the wrinkles etc.
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UPDATE 6

This could well be the final update before the finished photos are taken. Now my modelling enthusiasm has returned, this build had proved to be an enjoyable one!

One thing I've mentioned that could spoil a whole day was tackling the tail rotor conversion. Without trying to be technical, the Lynx is fitted with a spring bias unit housed at the back of the tail fin. In flight, this off-loads some of the aerodynamic forces acting on the tail rotor. On the ground, because of this very powerful unit, the Lynx should be parked with the right yaw pedal fully forwards.

At rest, the Lynx tail rotor blades are canted outwards, away from the tail fin. In their excellent 1/48 scale kit, Airfix have captured this beautifully. This photo shows a vertical red line with the kit tail rotor held against it, showing how the blades look when canted outboard.

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For my conversion to HAS.2 standard, I need to make the tail rotor travel in the anti-clockwise direction (when viewed from the left side of the aircraft) but also lean each blade outboard from the hub. If I simply put the tail rotor on "backwards", the blades would cant inboard, which would be totally incorrect. The kit rotor as supplied, travels clockwise.

The conversion starts with cutting the tail rotor blades off the centre hub. Gulp!
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I only cut off two blades at a time, as the rotor hub is too small for my sausage fingers to grip if I cut off all the blades. Re-mounting the cut off blades two at a time also makes it easier for me to achieve the outwards bias to each blade a little more easily as I have the existing blades to refer to.

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One job that must be carried out on each tail blade is to cut off the "spike" that's sticking up near the blade root, and to re-mount this very small piece of plastic on the opposite side of the blade root.


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It might be of interest that this spike-like item is actually called a Protruberence, and on the real aircraft, is a threaded rod. The idea was that weights could be added to the rods to balance the tail rotor.


Here's the assembled tail rotor in primer, having had all blades reversed and the pitch change spider unit fitted.


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This next photo shows the outward bias on the blades, having been re-mounted. The correct angles were achieved with a sanding stick versus trial & error

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Apart from painting, that's the tail rotor done and dusted. The outward canting of the blades is a small detail in the overall scheme, but one that I feel matters a lot. Of note is that in the Revell 1/32 scale kit, they've made no attempt to show this detail, but at least cutting the blades off the larger kit is a bit easier. :yipee


The main rotor blades were shown being modified in a previous update. The time arrived when I had to mount the blades to the hub.

In a "not again" moment, there are some MMM members that will know I have a bee in the bonnet about the Lynx main rotor blades being horizontal. On the real aircraft, there's hardly a millimetre of droop on the blades. On a model, this can be difficult to achieve, so I'll show my personal method of doing this.


Firstly, I put a peice of flat glass on my cutting mat. Mounting one blade to the hub (which is upside down) I tape the blade down in two places. I then mount the opposite blade and tape that down also.

As I have a sheet of glass large enough, I repeated this for the other blades. The rotor assembly is still upside down against the glass. I use the guide lines on the cutting mat to ensure the blades are correctly positioned relative to each other.

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Hving got this far with the main blade assembly, I put the glass sheet with the blades on in a position where I can leave it undisturbed for at least 24 hours while the glue bonds. Once given this time, I hold each blade down firmly with my fingers while I carefully peel off the tape, causing no flex or strain on the blades, and when turned the right way up - horizontal blades! Simples.


As I write, the model has been fully painted and marked, with all aerials and probes fitted. I've made intake and exhaust blanks and hung the correct type of Remove Before Flight tags on the model, to brighten it up a little. I won't cover the painting as we all know how to paint and frankly, there are others on MMM who can do that much better than myself. Also, it means that the first time I reveal the scheme will be a surprise for anyone who hasn't worked out which unique helicopter this HAS.2 is.

I think this one deserves a base to sit on, so I'll have a stab at that before I finish the model. For Mark - this will be a small base - CockpitFest friendly! :rolf

Finished photos in a few days time. Thank you for your comments.

Regards,

Nigel
:grin:





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Lt. Derek 'Smurfy' Reeve
You have the patience of a Saint if there was such a person Nigel.
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DevilFish
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LCDR Paul "Voodoo" Carter
:gob
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