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Just another Ballerina


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This morning I woke up happy. Went downstairs and opened the curtains to a lovely bright & sunny Saturday morning. I felt happy because it was the start of the weekend and I had all day to get a good start on my Ballerina...

Then I woke up again. But this time it was still dark and worst of all, it was still Friday! It was all a dream! crying

It's funny how things like that can put you in a bad mood for the day so this evening I cheered myself up by starting my Ballerina for real! I started by marking out and cutting templates for the formers on paper transfer tape. This is very similar to masking tape but comes on a big roll 8" wide. These were transferred to a ply sheet and 1/8th balsa rectangles already cut out.

My bad mood briefly returned when I sheared the screw off whilst tightening the blade grip on my scroll saw, leaving the remaining thread deep in the metal grip! Not really feeling like cutting the couple of ply parts with a coping saw I set about removing the grip ready to drill the broken thread and extract it with a stud extractor. My bad mood disappeared immediately when the drill bit started cutting but then gripped the thread and wound it straight out for me! 5 minutes later it was all back together ready to start cutting again. Must be a good omen?

So after an hour or so of cutting and sanding on the bench sander I have a pile of formers ready.

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Unfortunately I didn't have enough full lengths of 3/32 to cut the fuselage sides so they're on hold pending a shopping trip in the morning.

Finding a single length of medium 1/4 I cut and jointed the parts for the fin and rudder. No fancy built up framing for this Ballerina.

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Then onto the fun part, the wing ribs!

I started by making a template in ply which is basically the same for all the ribs except the tips. I then started cutting the ribs, marking them as I went to keep track of what I had cut and what was left. A lack of 1/8 lite ply meant I couldn't complete the set and that's on the shopping list for tomorrow as well!

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More progress tomorrow and hopefully this good mood will continue! laugh

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Hi Chris

Looks a good start to say the least. I have cheated and have gone for the CNC pack. I like your idea of paper transfer tape, have not heard of this before. Where do you get hold of this? I have used opaque grease proof paper in the past, redirected from the kitchen, but Tesco have changed the spec to brown which cannot be used (except for cooking of course!).

Cheers Peter

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My original had the dowel higher and the hole in the former higher. I don't soppuse it will make much difference but it is a little stronger when the hole is not quite so close to the bottom of the former.

Note also that the tailplane goes right up against F-10 so the sides are cut away to F-10,

Don't ask why. I think the final draughtsman likes to think he has added his onw personal touch or something.

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Posted by Low pass Pete on 09/01/2016 08:10:49:

Hi Chris

Looks a good start to say the least. I have cheated and have gone for the CNC pack. I like your idea of paper transfer tape, have not heard of this before. Where do you get hold of this? I have used opaque grease proof paper in the past, redirected from the kitchen, but Tesco have changed the spec to brown which cannot be used (except for cooking of course!).

Cheers Peter

I got some from Green Stik Crafts where I also get the vinyl rolls for my cutter. It's mainly used for car decals and sign writing to transfer the letters from the backing sheet then onto the vehicle.

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Posted by Peter Miller on 09/01/2016 08:30:33:

I see another one has fallen for the "grain across the formers". I should put a stip of balsa up each former to stop it falling in half.

I really must indicate the grain direction on the plan. The draughtsman has obvioulsy never built a model or he would not show the grain across the former.

Yep! I spotted that and pondered for a while why it was across the fuselage. I can see how it could possibly split across at the top of the fuselage sides but with the stringers glued in properly and F6 made in ply I doubt splitting will be an issue once the fuse is together. It did mean that I could use up a load of 30mm strips from the scrap drawer though! laugh

I do intend to change F10 though as any excessive twisting forces on the fin could possibly shear that former along the grain.

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Posted by Percy Verance on 09/01/2016 08:50:39:

I see you have retained the original wing dowel position in R1 Chris? One of the other Ballerina builders (can't recall whom sorry) has re-drawn R1 with the wing dowel moved up 1/4 of an inch, as the plan showed it rather close to the bottom of F2. The mod ought to give the dowel more hold/security.

It's a straightforward mod in that the top edge of the current dowel position in R1 becomes the lower edge of the new position, if you get my drift. The dowel position in F2 simply moves 1/4 higher.

Just thought I'd mention it before it was too late.......

Edited By Percy Verance on 09/01/2016 08:54:05

Thanks Percy

When I was marking out R1 I didn't think it was unduly low in the wing but having now cut the fuselage sides I see that the wing sits really low and the dowel would be right at the bottom of the fuselage. A good yank on the up stick and the fuse and wing may part company!

I am going to fit the dowel much higher up in the wing going through a ply plate housed in the leading edge and filleted to the top skin of the wing. This way the dowel will be around 15-18mm into the former.

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Posted by john stones 1 on 09/01/2016 13:57:43:

You woke up Happy did you ? Snow White having a lie in teeth 2

I,C version, what's going up front Chris ?

John

So glad I didn't say I woke up feeling grumpy then! That's terrible John! dont know

Yep staying i.c with an ASP .52 FS so it will make nice noises! The ASP isn't a vast amount more power than a good OS .40 FS !

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I find "normal" sloping quite challenging and great practice for cross wind flying that can be applied to powered flying. Good windy days are very exhilarating and TBH flying off something like the East side of the Orme directly over the sea is terrifying, but awesome at the same time!

The PSS flying is all the above with model jets, fighters, bombers, airliners, just about anything you wouldn't want to put a screaming EDF in or an expensive turbine!

But it's still not like landing a scale bipe on short grass just above walking pace! smiley

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Material shortages have caused a few delays in the Ballerina build but today I managed to get the missing 1/32 ply for the doublers. Unfortunately the wing for the Vulcan was on the bench part sheeted so had to finish a bit on that first.

Having cut the doublers I used EvoStik spray contact adhesive. I quite like the spray as it's very easy to get a thin, consistent coat on both sides. I sprayed one coat on both & let it fully dry before spraying another coat. It has 2 coats because the first soaks into the wood a lot.

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All 4 doublers (BEB wink  were then carefully positioned and pressed down. To prevent the contact adhesive from cupping the fuselage side the two pieces were laid on the bench and my fuselage jig placed over the top of them. The base is 3/4 ply so is quite heavy.

Since I had the jig out and the Ballerina sides on the wrong side of it I'm sorry to say I then built up the Vulcan fuselage and clamped it in the jig! I promise I'll get more progress on the Ballerina tomorrow! blush

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Tonight the motor mount was positioned and marked out. My engine will be mounted inverted.

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The holes were marked with a fine 0 point phillips screwdriver. This has the advantage of being almost exactly the same size as the holes in the mount plus it marks a lovely cross in the plywood.

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These were then drilled to take M4 captive nuts which were gently pressed in with a 16oz claw hammer and secured with a little cyano. (Shown after assembley!   )

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The positions of the formers were glued with a line of aliphatic then the whole fuselage assembled in the jig Starting at the front end working backwards former by former.

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Making sure F3 and F5 are square to the cockpit floor

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The great thing about aliphatic is that there's loads of time to adjust and setup the whole fuselage before the glue starts to set.

The grid vinyl sheet you get with the Slec jig comes into it's own here. The fuselage is lined up on the grid using centre lines marked on the formers and a former, in this case F2 is lined up across the jig. As long as the centre line and cross lines still line up at the tail your fuselage will be straight!

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Now it's all left for the glue to set!

Edited By Chris Barlow on 12/01/2016 23:21:28

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