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Chris Barlow17/03/2018 21:32:07
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1904 forum posts
1308 photos

Just about ready to make a start on my Hurricane now the Catalina is ready for rescue missions in September!

My attempt will be based on Z3055, a Mk IIA recovered from the Med near the Blue Grotto, Malta and displayed in the Malta Aviation Museum.

The only (weak) connection I have to this example is that we will be going to Malta in August for a family holiday so will have the opportunity to get a close up look at it for finishing details, although I would hope that by then my PSS version will be 99% complete and test flown!

So, TO THE MAN CAVE!.......

Dave Cunnington17/03/2018 23:11:02
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143 forum posts
38 photos

malta h4.jpgmalta h3.jpgmalta h2.jpg......malta h1.jpg..and I just happened to be in Malta in 1995 when she came ashore

Haven't Ray and the guys done an incredible job !

Former Member18/03/2018 01:57:20
3578 forum posts

[This posting has been removed]

cymaz18/03/2018 06:18:45
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9004 forum posts
1187 photos

Nice subject Chris..Is it going to be hard to replicate the sea debris on your model?laugh

Percy Verance18/03/2018 08:07:52
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8108 forum posts
155 photos

Tom

There's also a fully airworthy Gladiator at the Shuttleworth Collection based at Old Warden in Bedfordshire. It is flown from time to time too.

I think there are some pics on the Shuttleworth site...... they also have a fully airworthy Lysander, which I think had a similar engine. I have seen that fly on a couple of occasions.

Lysander. Larger than you may imagine.......

lysander-2.jpg

 

 

Edited By Percy Verance on 18/03/2018 08:11:52

Chris Barlow18/03/2018 16:58:22
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1904 forum posts
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Posted by Dave Cunnington on 17/03/2018 23:11:02:

malta h4.jpgmalta h3.jpgmalta h2.jpg......malta h1.jpg..and I just happened to be in Malta in 1995 when she came ashore

Haven't Ray and the guys done an incredible job !

That must have been quite an event to watch Dave! smiley

Yes from what they had to start with it looks spot on now. Amazing job.

Chris Barlow18/03/2018 16:59:07
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1904 forum posts
1308 photos
Posted by cymaz on 18/03/2018 06:18:45:

Nice subject Chris..Is it going to be hard to replicate the sea debris on your model?laugh

Plenty of lettuce in the fridge Cymaz...!

Chris Barlow27/03/2018 22:18:03
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1904 forum posts
1308 photos

OK.

I made a start....

20180327_221046.jpg

Onwards...laugh

Chris Barlow28/03/2018 00:01:34
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1904 forum posts
1308 photos

Usually there is a flat side somewhere on the fuselage to cut the fuselage side to and then make up the curve after with additional panels, but this one is mostly curved after F3 so I assume the laser cut fuselage sides are oversize?

The plan says the sides are oversize for the curve too but a simple measure reveals that must mean the wood pack and not the actual drawing, so....

If we look at the side elevation of the plan the former appears to be the correct size, and it is.

20180327_232244.jpg

But if we roll the former over the plan the top edge of the fuselage side is a long way from the top center line of the former.

20180327_232328.jpg

...because it's a 3D former interacting with a 2D plan!

To get the real fuselage template I started by marking the center line of the plan onto the formers by measuring up from the bottom edge.

20180327_232411.jpg

And marked it from the bottom edge of the former

20180327_232448.jpg

I stood the former up on the copied outline of the fuselage side, lining up the center line on both parts

20180327_232540.jpg

Then rolled the former over the curve to get the true "top edge" of the sides

20180327_232625.jpg

I did this for all the formers in all the former positions, joined them up and marked with chevrons ready for cutting. If you're struggling with the idea of rolling the former over the template then imaging the template as the balsa sides rolled over the former like so...

20180327_232818.jpg

Of course that's just my take on it and could be completely wrong, in which case I'm back to piecing in the curves with separate panels again!

Does any of that make sense?

john stones 128/03/2018 00:08:39
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11109 forum posts
1500 photos

Yep.

Phil Cooke28/03/2018 11:00:24
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2438 forum posts
1686 photos

Chris - the oversized fuselage side template is shown on Sheet 2 of the plan. This is sized correctly to allow for both rolling over the top/underside AND the 'pull in' effect of both the nose and tail.

If you are cutting all your formers from the plan and maintaining the position of the a drawn fuselage datum 1/2" doubler, then you can EITHER raise the doubler by 2.5mm or lower the doubler recesses by 2.5 (which is how Sarik have corrected this issue if you were to purchase a kit today)

Andy Meade28/03/2018 11:13:12
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2746 forum posts
704 photos

Good to see a proper build on the go though Chris, with knocking out your own profiled parts yes

Alan Gorham_28/03/2018 11:15:05
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1165 forum posts
133 photos

Chris: as Phil says, my reading of the plan shows an oversize fuselage side "flat" on the page on sheet 2.

Good work in interpolating the fuselage side from the former shapes though.

Chris Barlow28/03/2018 18:10:05
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1904 forum posts
1308 photos

Yep, found it. Thanks guys! angry

laugh

I had only given sheet 2 a cursory glance, saw the ribs and put it back in the box! lol Still it was an oddly enjoyable excersise, marks the center ref on all the formers and checks the former dimensions at the same time!

Having traced the oversized sides onto my template there are some differences shown by the dotted lines.

20180328_165117.jpg

The plan side is mostly oversize compared to the plotted template. Does anybody know if it is deliberately oversize to be sanded back after assembly?

Phil Cooke28/03/2018 23:15:07
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2438 forum posts
1686 photos

Yes, deliberately oversize I think. thumbs up

Chris Barlow31/03/2018 02:12:28
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1904 forum posts
1308 photos

After a couple of busy evenings I have managed to glue up a fuselage, and it didn't go without a fight!

The battery box and nose section was as usual very easy to assemble and dropping the sides and formers into my slec jig the flat section of the sides glued up nicely. That was the easy bit!

With the fuselage still in the jig I soaked the sides and nose in ammonia and left it for 30 mins ready to pull in to the formers. Unfortunately when the sides pulled into F5/F6 that created a horrendous bulge between F6 and F8 and across the open cockpit area.Easing the bulge around the cockpit caused the sides to lift off the formers F3 and F4 and pinning them back down again recreated the bulge in the cockpit! The bulge between F6 and F8 either popped outwards or when pushed back popped inwards so the sides were only 1/4" apart!

To add to this frustration as the ammonia dried out the 1/8 sides shrank and pulled off the concave part of F5/F6! After messing around with it for an hour I decided I needed to release it from the jig and manually pinch and glue as I went along! So anothe dose of ammonia on the outside only and I gradually inched my way along the formers, pinching and tacking with small drops of thin cyano. This worked quite well but I was unable to manage the bulges between F6 and F8. I decided I would deal with that when fitting the 10mm spine! This bulge was to cause another problem though in that I had no way to hold the sides in position whilst sanding then flat to the top of the formers! I ended up clamping a 3/8 x 1/2" spruce strip to the side level with the top edge of the formers and cutting with a scalpel, repeating with the other side.

The spine was cut to the exact size, glued and pinned to the top of the formers. I then pulled the freshly ammonia dosed sides flush to the sides of the spine and pinned them in place. when dry I tacked them in place with drops of cyano from the outside and ran aliphatic resin along the joint from the inside of the fuselage. This seems to have worked to line up the sides to the spine but as the ammonia has dried out the balsa has shrunk slightly and pulled tight, loosing some of the concave curve from the top half of the fuselage.

In comparison the 3/4 triangular stock and 10mm bottom plank fitted easily and fitting the servo mount and snake outer was a simple, standard affair.

So a frustrating but productive couple of days which at one point had me gripping the nose between my legs and pinching the sides to the formers with my right hand and left wrist whilst trying to apply drops or runny cyano with my left hand! Oh and I dropped the fuselage twice creating a dent in the side that will have to be filled! surprise

20180331_003703.jpg

Thank god for big joinery tools! I did consider using 4" screws at one point!

20180331_011527.jpg

Looks a little better after being cleaned and sanded a little.

20180331_011552.jpg

Servo mount and snake installed. The snake was no where near a solid part of any of the formers in it's relaxed route so I had to make some supports from 1/8 lite ply. There are 2 more for F7 and F8 inside the fuselage!

Next is the nice and simple job of blocking out the nose section!

Paul Marsh31/03/2018 11:03:16
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3834 forum posts
1110 photos

Chris had some fun with those sides yesterday! I did build a Hurricane years ago, think I sold it. It did have longeron sides, which were scale and avoids the problem Chris had.

found a photo:

Phil Cooke31/03/2018 20:46:12
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2438 forum posts
1686 photos

Sorry to read you've been wrestling with the fuselage Chris, this 1/8" sheet bending is by far the most testing phase of this particular build - but once done it really does capture the characteristic scale shape of the full-size.

I wonder whether an incremental approach would be better for those yet to face it - perhaps bending the fuselage just over the top of the full-length doubler first and gluing it to all formers at that point, before allowing it to dry firm then having two more attempts over two more sessions - first around the central cockpit region F4 to F6 then again working outwards - both fore and aft from the cockpit towards F3 and F8. As I learnt with the fuselage 'key' don't use a water based adhesive is more ammonia is to be applied later.

I've got this stage to come next on my build. As you say clamps are a must, and I think Ill make some tailored rounded clamping blocks to press into the re-entrant zones behind the cockpit.

One other thought - Is it possible also to 'over-wet' the fuselage sides - making them just too plastic and enabling the 'bulging' (almost folding) of the sides when the ammonia is at is strongest phase?

Chris Barlow31/03/2018 23:02:46
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1904 forum posts
1308 photos

If it weren't for these little battles where would our small victories come from? laugh

I may re-wet the sides behind the canopy and clamp a couple of 1" round balsa to the sides to "mold" the curve back in!

Phil, although the sides were wetted and dried several times they were not really soaked and seemed to retain the stiffness along the grain which probably caused the bucking along the length.

onetenor01/04/2018 00:06:36
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1901 forum posts

Soft. STRAIGHT GRAINED balsa is best for that kind of moulding fuselages.

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