The DeHavilland Sea Hornet NF21- Classic Airframes 1/48th model, with a few embellishments

[Col.]

Cracking progress Jon.

[Martian]

Vast improvement over what you get in the kit!

Martin

[Jon Kunac-Tabinor]

Cheers Chaps!

so thanks to a bit of indigestion I was up early this morning, so aftera final check that the UC leg asssemblies could be fitted through the wheel well openings ( one needed a tiny trim I found), I cemented the necelles onto the wings. Fit was Ok, and improved a bit more after some final fettling of the mating surfaces. Hot Plastic Weld did a good job of melting the joins together - meaning there was just a few gaps to fill- mainly at the rear, plus the pen nib rear nacelle tips have need a bit of filling, and a shim of card on one on the top to bring it level with the top wing surface.

However when I did a tape assembly of the wings to fuselge, the tape I laid on the top wing to hold it all there did a suberb job of removing the filler in the wing panel lines, so tonight these have been re-filled with Mr Dissolved putty and put aside to harden. I'd used a Pentel liquid paper roller ball the first time - which worked great, but obvioulsy hadnt really stuck to the plastic.

Next up is the fuselage cannon shell ejection ports.

Onwards and upwards!

Cheers

Jonners

[Andrew Jones]

This is looking great Jonners, really like the undercarriage work, keep this up and you're going to have a real work of art in this one.

Andrew

[Jon Kunac-Tabinor]

Ok- so now for something completely different...well OK not that different: The Fuselage length. A perusal of the various threads seems to indicate the kit has a short fuselage.

So in my own inimitable style I did a bit of measuring using the Warpaint book plans ( Im aware they are considered "not perfect") - and the model shows up a discrepancy of about 7 to 8 inches 'short bottom' style. I took a series of measurements using the SAM scale rule, using waypoint of the fuselage such as rudder hinge line, wing trailing & leading edge, canopy positions etc. to come up with this.

Now the short arsedeness seems to occur between the wing trailing edge and rudder hinge line, specifically ab aft of the observers cockpit and towards the fin. SO....

...What I've done is make a cut to separate the fuselage after the observers pit, towards the leading edge of the fin fillet. Then I've cemented in a 4mm thick-plasticard extension in to place ( roughly 8" at 1/48th scale). Im not being exact on these dimesniosn because my own measurements are not precise - but its good enough for me!!

This extension looks Ok to my eyes, and also seems to solve the problem of why a lot of CA Hornet builds' sits look 'stalky' too - the extended rear fuslelage should give a more graceful line and will allow the model to sit at a slightly less acute angle.

Hope I'm right 'cus the deed is done.

Pics to follow.

Jonners

[gruffy]

Watching this build with interest!

[Martian]

Can we have some pictures of the extension please John! I hadn't picked up on this although it has to be admitted that I haven;t got round to comparing the kit against a plan yet.

Martin

[Jon Kunac-Tabinor]

Can we have some pictures of the extension please John! I hadn't picked up on this although it has to be admitted that I haven;t got round to comparing the kit against a plan yet.

Martin

Here you go - photoshopped - as i didnt take any before I did it - but you get the giste I hope. I think you'll see the improvement when its all buttoned up but it does add a noticeable stretch.

Cheers

Jonners

[ththtttu7]

Hi Jon,

That's some excellent work you are doing here on the NF21.

Its great that you are lengthening the rear fuselage to its correct length.

Don't forget to fill over the upper wing panel lines - there weren't many! It is all doped fabric over wood.

If you are looking for some cockpit shots (front and rear) for the NF21 I'll add some to the the Hornet Project website: www.dhhornet50.net

Hope this helps?

[Jon Kunac-Tabinor]

Hi Jon,

That's some excellent work you are doing here on the NF21.

Its great that you are lengthening the rear fuselage to its correct length.

Don't forget to fill over the upper wing panel lines - there weren't many! It is all doped fabric over wood.

If you are looking for some cockpit shots (front and rear) for the NF21 I'll add some to the the Hornet Project website: www.dhhornet50.net

Hope this helps?

David - many many thanks ( which hardly sums it up at all) . A PM will be on its way.

Just got back from Carfest. So work will continue with an update tomorrow.

Cheers alll

Jonners

[ththtttu7]

Hi Jon,

Here are the images of the NF21 rear observers position.

Looking forward.

Looking to port.

Looking rearward.

NF21 Cockpit images to follow.

Edited August 28, 2012 by David A Collins

[Jon Kunac-Tabinor]

Hi David - many many thanks for this. It looks as though CA have got the Radar gear fixed to the rear bulkhead- ie back to front!!

Must have been fun trying no to snag those control cable runs too!

I'm assuming that in the pic of the rear bulkhead, those 4 large bolt hole attachement points are the mounting points for the observers folding seat?

Top wing panel lines are just on their 4th fill and sand ( they keep reappearing, the light blighters)- pics on here when Im happy.

Ta muchly much!

Jonners

[Martian]

According to the Air Publication, the observer's seat is attached to bulkhead no.3 which is at the forward end of the rear cockpit.

[ththtttu7]

Hi Jon,

I think the 4 large bolt hole attachement points you refer to, are the mounting points for the radar so CA have got the location correct, ie. on the front face of bulkhead 4.

Here are the Sea Hornet NF21 cockpit photo's as promised.

Front view

Port side view

Stbd side view

The observer/radar operators seat was rear facing, and indeed mounted on the rear face of bulkhead number 3. Its base was hinged to allow the aircrew access through the door underneath. The photo's I have posted showing the rear cockpit seem to have the seat and main radar viewing screen missing. Also, referring to the aft looking image, there is a zipped bulkhead to allow access to the extreme rear fuselage. It is shown in the unzipped condition!

Hope these are of use?

As for cockpit colours - everything is black! With the exception of the seat, which is a brown/leathery colour.

Edited August 29, 2012 by David A Collins

[Jon Kunac-Tabinor]

HI all - while I work out how much extra detail I want to add to the 2 cockpit areas, I've been carrying on with the "hard landscaping":

Tailplanes and eleveators have been separated and articulated, and the 2 fillets that fair in the elevators added to the fueslage and blended in.

Cannon shell ejection ports have been added, and wing tip lights and landing light added and polished.

Second pic also shows the top wing panel lines filled - and the area that has been giving me grief and needs refilling again, again!

I've also been working on the spinners - whihc seem too short and weirdly curved in profile. here you can see a strip of plastic card thats been cemeted around the spinner base-plate to extend the length, then the spinner is attached and its filled, secured in a dremel motor tool and then sanded to shape. I've glued a spare 4 blade prop hub inside, drilled so the blades can be added later. If I'm happy with this then the other spinner will get the same treatment.

sorry for the blur- camera was having focussing issues! but hopefully you get the giste.

Next up is adding the wing fold bulges to the wings. Just need to find some clear shots of them.

Cheers

Jonners

[ththtttu7]

Hi Jon,

You are continuing to make excellent progress.

Don't forget that the RH engine nacelle is slightly longer than the LH one. Its due to the extra gear on the front of the engine to rotate the prop the other direction compared with the LH one.

Take a look on the net for a larger photo of the Hornet F3 shown in my Avatar. You can clearly see the RH "nacelle plug" between the spinner and cowlings for how big it is. The photo is on the rear cover of my book if you have a copy.

[Jon Kunac-Tabinor]

Hi Jon,

You are continuing to make excellent progress.

Don't forget that the RH engine nacelle is slightly longer than the LH one. Its due to the extra gear on the front of the engine to rotate the prop the other direction compared with the LH one.

Take a look on the net for a larger photo of the Hornet F3 shown in my Avatar. You can clearly see the RH "nacelle plug" between the spinner and cowlings for how big it is. The photo is on the rear cover of my book if you have a copy.

Now that I never knew!! Thanks David - you are as ever a mine of info. Whats the current state of the real thing BTW?

Jonners

[ththtttu7]

Now that I never knew!! Thanks David - you are as ever a mine of info. Whats the current state of the real thing BTW?

Jonners

Just bits and bobs to report at present.... house extension current "work in progress!"

A couple more internal cockpit brackets have been drawn up, and a new wooden LH console has been made. Other than that, I'm looking forward to extending the forward fuselage rearward a further 1.5 meters, to fully support the canopy and include a section of centre wing spar too, as soon as the building has finished.

[therollercoaster]

Hi Jon,

You are continuing to make excellent progress.

Don't forget that the RH engine nacelle is slightly longer than the LH one. Its due to the extra gear on the front of the engine to rotate the prop the other direction compared with the LH one.

Take a look on the net for a larger photo of the Hornet F3 shown in my Avatar. You can clearly see the RH "nacelle plug" between the spinner and cowlings for how big it is. The photo is on the rear cover of my book if you have a copy.

I always thought the reason for two Merlin type numbers for the Hornet was that one turned in the opposite direction to the other, The Merlin 130 and 131. The engines were handed not geared.

[Jon Kunac-Tabinor]

I always thought the reason for two Merlin type numbers for the Hornet was that one turned in the opposite direction to the other, The Merlin 130 and 131. The engines were handed not geared.

Hiya - so did I but it transpires the engines were about 95% common. The 131(I think) used an extra gear in its reduction casing to turn the prop shaft the other way.

http://users.skynet.be/BAMRS/dh103/powerplant.htm

Will explain it far better, and save me copying too!! I'm guessing they were numbered differently just to differentiate which turned which way, rather than being different engines per se.

Cheers

Jonners

[Jon Kunac-Tabinor]

Ah Hubris!

Here I was going to post these shots of the spinners, nicely extended. Pat on the old back, smug grin etc etc, when from Mount Olympus, a lightning bolt of peripeteia flashes....

It was only when I added the thimble nose and took these that I realised the nacelles with the extended spinners now look too long. They are only marginally shorter than the nose snout now, and the difference should be more apparent. Me thinks the orginal spinners, while short, weren't quite as short as I thought.

I should of checked this before hand of course, but was so pleased with the work I just badgered on blindly.

So I'm going to crack them and reduce the extension a tad. Arras! and other villes in the Pas de Calais departement...( Fampoux! springs to mind as another onomatapeic town-term, and I'm definitely feeling a tad Lumbres too)

Jonners

[Dave Swindell]

I always thought the reason for two Merlin type numbers for the Hornet was that one turned in the opposite direction to the other, The Merlin 130 and 131. The engines were handed not geared.

Hiya - so did I but it transpires the engines were about 95% common. The 131(I think) used an extra gear in its reduction casing to turn the prop shaft the other way.

http://users.skynet..../powerplant.htm

Will explain it far better, and save me copying too!! I'm guessing they were numbered differently just to differentiate which turned which way, rather than being different engines per se.

Cheers

Jonners

All Merlin engines were geared, the propeller was turned via a reduction gear at the front of the engine. The "engine" part of the Merlin 130 & 131 is identical and rotates the same way, the gearbox on the front is different to produce handed propellor rotation.

Thanks for the link to the power plant page Jonners. Having seen the gearcase drawings and being a bit pedantic, I think the "extra Idler gear" is a myth. From what I can see, both engines had 4 gear wheels in the gear box, crankshaft output, propeller drive, PTO (or is it starter in? I'd need to check on that) and an idler.

The size & position of the idler did change however.

In the drawing of the gear casing on the left the crankshaft gear drives the propellor directly, and the propellor gear drives the PTO through an idler gear to give PTO & propellor rotation the same ie opposite to crank rotation.

In the drawing on the right the crankshaft drives an idler gear which then drives both PTO and Propellor to give crank, propellor & PTO rotation the same.

Interestingly this means the PTO (or is it starter?) also turns opposite directions between P&S 130/131 engines as well as the prop!

What is puzzling me now is why would one nacelle need to be longer than the other? It's often quoted as being because of the differernt gearing, but the gearing is all in the same plane and wouldn't add any length to the overall engine.

Excellent model Jonners, lots of info and inspiration for my SH 1/72nd ones when the round tuits arrive!

[ththtttu7]

What is puzzling me now is why would one nacelle need to be longer than the other? It's often quoted as being because of the differernt gearing, but the gearing is all in the same plane and wouldn't add any length to the overall engine.

The front of the RH engine nacelle is definitely longer than the LH. It is shown on the original DH drawings and is clearly visible in many good photos. An example being my avatar.

[Dave Swindell]

The front of the RH engine nacelle is definitely longer than the LH. It is shown on the original DH drawings and is clearly visible in many good photos. An example being my avatar.

s

I'm not disputing your findings David, just curious as to why. From an engineering point of view the different gearing on its own shouldn't make any difference to the length of the two engines

[Jon Kunac-Tabinor]

OK just a thought here - perhaps it was assumed the engine would be longer, so the nacelle was developed to fit? But in reality it didnt need to be? but then it was consider not worth changing the nacelle design back?

Or the gearbox case was actually deeper for some reason that is now lost to posterity?

Anyhooo.....reshaped shorter spinner now waiting for filler to dry, and a quick check shows the prop blades will "line up" on the fuselage where they should be. So I think I got away with it!

Finally added some paint - going to get the exhaust flame dampers added - so I need to get this bit painted and squared away first.

Cheers

Jonners