Wide Body Avro Atlantic

[kitnut617]

So up to now, things have been going fairly well.  But I've had a couple of problems to deal with.

First one was when I decided to glue on the shape I bent in the microwave, for some reason or other it holds it's shape 'very' well.  Didn't matter how much I tried to un-bend some of it, it would return to the shape I bent it at.  So when I went to glue it on I had to clamp it down while the glue dried.  But afterwards once the the clamps came off, I found I had clamped it too tight so it ended up with some concave faces.  In hindsight, I should have glued in some extra formers but I didn't think it needed it at the time.

So I've had to revert to Carlos' method of laminating some styrene but I'm not sure it has glued 100% even though I flooded in between the sheets with liguid glue.  Anyway, end result is that I've a bit more work to do with the PSR.



I did put in some extra formers for the next development



And then cut out the next development



I glued it on like the first development, by starting with the middle finger, then glued a couple more together and then let dry.



I only do a couple at a time so that I can get inside with the glue applicator and glue the fingers to the formers, like this



Then I roll a rubber band over it to hold it while the glue dries.

[James]

Looking good. Enjoying this build. 

[kitnut617]

The second problem I'm having to deal with is that my developments are not quite right, I tried to short-cut how I did them but each time the shapes didn't fit very well, even though the end result came out alright.  The first development I didn't cut enough of the plastic out between the fingers, the second develpoment I cut too much so I ended up with having to add a couple of fillers in.

In the last pic above where I have the rubber band in place you can see the gaps I've got. On the plus side the fingers form themselves over the formers pretty much how the end shape should be but for the last development I decided to work it out properly.
I've a number of books which detail how to do sheet metal developments (five of them which I use for my day job) but there's not one that shows how to do a paraboloid so I've had to do a bit of thinking about it.  One of my books does show how to do an elipse to round and reducing at the same time with the centers above each other, there's also one for an offset center layout but these both have straight sides but they did offer a clue on how to do a paraboloid (to me anyway).  It seemed to me that to develop a paraboloid it is actually a series of either round to rounds or elipse to rounds (as is my case) so I spent an afternoon figuring it all out.

Here's actually what a paraboloid development really looks like, in this case the rear underside of the fuselage tail.



Each one of those boxes with a cross in it has been individually worked out and no two are the same (although from the center line one side is an exact mirror image of the other) and each one of the lines (except the horizontal center line) are all curved but not at any constant radius.  

But here's the catch, you can't use this on a flat piece of styrene and then just bend it around the formers on the model.  If this was done in metal you would bend it by using a bit of machinery called an 'English Wheel'.  This machine 'dishes' the shape so you get the compound curves in all directions.  I think what I'll do is print this on some cardboard and then cut along the long lines to make it into 'fingers' and then see how it offers up to the model. If that works I'll do it in styrene

[PR19_Kit]

...... so Hawker Siddeley immediately started contractual talks with A.V.Roe to build the Atlantic for them, and they came to agreement to build 30 Atlantic C.1's and 20 K.2's for the RAF.

And what about the C(K)3s for the RCAF?  

Wonderful construction details Robert, it's going to be a landmark model when you finish it.  

[kitnut617]

...... so Hawker Siddeley immediately started contractual talks with A.V.Roe to build the Atlantic for them, and they came to agreement to build 30 Atlantic C.1's and 20 K.2's for the RAF.

And what about the C(K)3s for the RCAF?  

Wonderful construction details Robert, it's going to be a landmark model when you finish it.  

Cheers Kit --

I've been thinking about what marks might have appeared and this is what I've come up with.

C.1 -- with Vulcan B.1 wings and engines (Olympus 101), transport
K.2 -- same as above but a tanker
C.3 -- with Vulcan B.1a wings and engines (Olympus 201), transport
K.4 -- same as above but a tanker
C.5 -- with Vulcan B.2 wings and engines (Olympus 301) option not proceded with as production was about to switch to the wide- body Atlantic.
C.6 -- RCAF variant with specific Canadian equipment, B.2 inner wings, B.1a outer wings, Orenda Iroquois engines without afterburner (same power as Olympus 301 but in a smaller package)    

But here's something else that the C.6 is going to have ---- a swingtail ---   and in Canadian service it was called a CC-137 Husky ('cause the RCAF didn't buy the 707)

[IanH]

...... so Hawker Siddeley immediately started contractual talks with A.V.Roe to build the Atlantic for them, and they came to agreement to build 30 Atlantic C.1's and 20 K.2's for the RAF.

And what about the C(K)3s for the RCAF?  

Wonderful construction details Robert, it's going to be a landmark model when you finish it.  

Ditto from me

[Pablo1965]

Heavens! It's really a craftwork. I used Milliput to fill all but you made a real fuselage.

[kitnut617]

Don't worry Pablo, the putty is coming ----- 

Thanks for the comments though   

[IanH]

Don't worry Pablo, the putty is coming ----- 

Thanks for the comments though   

Aye but not as much as mere mortals like myself

[Weaver]

Just catching up with this: what an outstanding piece of work! 

[McColm]

impressive!!

[John Howling Mouse]

Amazing craftsmanship.  And I completely understand the complexities and frustrations of dealing with compound curves.

[kitnut617]

Thanks Barry, everyone --

The build has slowed down somewhat, very busy workwise and now summer has finally decided to show up and lots of other things to do around the property, the main being trying to keep 4 acres of grass cut.  If only the weather would co-operate though.  We had a very close call a couple of days ago, three tornadoes (not the planes) touched down only about 50 kms away and the weather warning announcement came on and said it was travelling eastwards, and that was straight at us.  Fortunately, it went north-northeast barely missing four towns, one farmers property got picked up and dumped somewhere else but no injuries anywhere thank goodness.

I have managed to procede with the skinning of the tail end, the final development has been worked out and trialed on some cardboard. First attempt I cut the development into the fingers I've been doing, leaving the large end connected.  But I couldn't determine if it was right, so I did another one only this time leaving the small end connected together.  That was about as successful as the first try but then I thought about it a bit, I realized that I didn't need to cut either end completely as the development should be the correct shape (only flattened).  I pondered on how to 'dish' the shape and came up with the idea of heating it and then forming it but I quickly change my mind about that. The solution was just to cut along the curved lines but leave about 3/16" each not cut each end.  Once I did that I could bend the shape width wise, then roll the shape up at the ends, it 'dished' pretty much how I wanted it to.




Now I've started to do this on styrene, first printing the shape on the label sheet then sticking it to the plastic.  I'm cutting along the lines before I cut the shape out completely, helps holding everything down by doing that.



As the tail end is getting close to being finished, I've started to think how I'm going to fit the wings on.  I've drilled some large holes in a sheet of styrene and from there I will layout each former. I'm going to put a former every 3/4" so what you see here will do one side. or half of both sides at the same time.



Another thing I will have to do is finish off the inner wings, that's cleaning up the air intakes and painting some of it.  I also decided to add some turbine blades to the exhaust, for some reason Airfix decided to leave this end as 'see-through'.  My plan was to file out the exhaust nozzles and then slide a bit of tubing up as far as where the ends of the engines would be, which is just forward of the rear spar.  But things got carried away a bit ----  




Anyway, that's where I am at the moment.

[GTX]

You're going to have to try harder than that to make us stop praising you

[Gondor]

That brass exhaust looks the business. As always I am amazed by the skills my fellow modellers produce regularly 

Gondor