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Simon's Ballerina


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Here's my blog to record another Ballerina begun. Had some issues to start with as my photocopier wasn't copying exactly square when making the templates so had to compare every copy back against the plan

Updates may not be frequent as I have a number of other things on and building will therefore be fairly slow. I used to build when I was a teenager - brought up on tissue paper and dope - but I've only in the last year or so come back to building and flying. Here's one I did earlier this year - the Seagull Challenger built-up kit covered in HK film.

Red Challenger

My bits box had nearly everything - I only really needed a bit more 1/4" sheet and the spruce stringers.

So far I've cut out the tail surfaces, the fuz sides and doublers:

Tail parts

 

Fuselage sides and doublers

The elevators will be separated after I've sanded the leading edge to shape and inserted the joiner.

My 1/32 ply wasn't quite big enough so the front pieces are joined with a triangular inset butt joint (not sure if that's the right terminology), seems very strong after gluing to the balsa sides.  You can just about see the joint on the doubler on the cutting mat.

This picture also shows some of my favourite tools and other essentials:

  • strong glasses, 'cos my eyes are useless now!
  • Radio remote control!
  • my old friend, No. 11 Swann Morton scalpel - blades work out about 9p each bought in bulk, Used for all sorts - the point is very fine so can be used for teasing as well as cutting, but the angle on the back of the blade is useful for scraping too
  • long and short metal rules
  • a selection of my home-made sanding blocks - the small one is a bit of 1/2 x 1/8 pine strip wood with coarse and fine grades on opposite flats, and a strip on the edge of the other end. All stuck on with Pritt Stick so very quick and easy to change
  • A supply of ever sharp pencils and a soft one too
  • Amazon Prime free trial plastic card (!!) - these come through the door from time to time and I use them for applying lightweight filler, glassing and (in this case) spreading the glue layer thinly for laminating the doublers to the fuz. The doublers were weighted down whilst the glue dries with granite place mats - very very flat, and very heavy!

The model will be electric, probably a Turnigy 3548 840kv (as I have one available, and it worked VERY well in the Challenger) running on 4s; two aileron servos, covered in HK film. I have a scheme in mind...

Oh, and here's something else I discovered recently and already finding really useful:

Fast Tak - useful for temporary positioning of paper templates

You spray this on the back of your paper templates, and it makes them act like post-it notes - you can stick them to the wood for cutting, and reposition them as necessary. Definitely not permanent - peels off by itself after a while - but holds the template down a treat long enough for cutting and doesn't seem to leave any residue when you peel it off. It's just a bit smelly.

Now the question is whether it'll be finished in time for the mass build meet!

Edited By Simon Feather on 07/01/2016 00:10:03

Edited By Simon Feather on 07/01/2016 00:10:53

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Posted by Simon Feather on 07/01/2016 12:10:52:

just discovered you can get a better value tin of Fast Tak from Amazon - HomeBase charged me £4.49 for 150ml, but Amazon charge £9.49 for 500ml. I'll see how long the little can lasts!

Sounds good but the postage might bring itup close toSpray Mount.

These days I use spray contact adhesive for my doublers. too.

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That £9.49 was including postage so perhaps not too bad... spray mount is a lot more permanent, this stuff is VERY temporary so will have a very limited and specific use! Good idea using spray mount for doublers though, that'll be very quick. I used PVA weighted down and that needs overnight to set properly.

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Craig - I agree, I'd been using Pritt which is fine as long as you don't leave it on too long. I saw the Fast Tak in the shop and thought I'd give it a go... seems ok so far, we'll see how it behaves - and lasts - longer term.

Peter - I live near Wakefield, and we have loads of those little hardware shops round here! It seems every little town has one... little goldmines, nooks and crannies packed with interesting and sometimes dangerous stuff. My local one, 10 mins walk away, still sells nails and screws loose and better still, it sells 1mm and 2mm drill bits loose in little paper bags!

I won't have time now to do much more on the Ballerina for a few days, will update when I have a bit more progress to report. I did roughly sketch out the battery hatch last night - mine will be full length from the firewall to include the cockpit area right up to F5, which I'll install slightly canted backwards to make for easy hatch removal and replacement. Just seemed easier to make all that section one piece rather than try to make a join in front of the windshield. We'll see how that goes.

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Well, some progress - but not a lot (on this job, anyway)!! Spent some time last night swearing at photocopiers that don't copy precisely square. I have several other jobs on - besides family commitments! So the Ballerina may be a bit slow to get going in full swing. But photocopiers that don't do their job properly don't help...

I've got a repair on (following an uncommanded dive off to the left during a right hand approach turn... ) that has now got to the stage of recovering, but I don't have enough of the original covering to finish so that will now have to wait until more arrives in the post. Major success for tonight is that I've managed to complete a prototype for a sound unit (I do hobby electronics too, this is a commission for a large bird model, needs to squawk on demand), works really rather well so quite pleased with that, can play any mp3 using switches on the tranny, so low pass playing Star Wars or Ride of the Valkyries now entirely possible). But on the Ballerina, today all I've managed to do is laminate two lots of 1/8 ply as I had no 1/4 in stock, then cut out F1 slightly oversize on the bandsaw (due to photocopying errors - pah!) and then sand it back to the correct size. Didn't take long, but I wasn't able to start 'til 10pm! Hopefully tomorrow will be more productive - I certainly hope I can manage to cut out more than one former a day!

Simon

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Major success for tonight is that I've managed to complete a prototype for a sound unit (I do hobby electronics too, this is a commission for a large bird model, needs to squawk on demand), works really rather well so quite pleased with that, can play any mp3 using switches on the tranny, so low pass playing Star Wars or Ride of the Valkyries now entirely possible).

Hi Simon. That looks interesting. Are you planning to open a separate thread on this device? (I like the idea of a los pass with the Ride of the Valkyries...smile d)

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AVC - I may well post more details on my prototype sound module, but only after it's been demonstrated to the commissioner and perhaps after I've soldered up a slightly more elegant (and louder!) version . (prototypes, hey).

On the Ballerina, I've spent time designing the battery hatch and what modifications that means to the formers. Still more challenges due to the (*unmentionable*) photocopier. Not used this one for copying templates before, and won't be doing so again! Most of the formers are now cut out - only the modified F2 to go.

Then perhaps time to get jigging... I have only limited time for building at the moment, unfortunately, so this could take a while...

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  • 2 weeks later...

Hi all - just to let you know I haven't gone away, just been busy with various other things. I've got a couple of other aeromodelling jobs on too, so in what time I have had I've been working on a f/g cowl repair (which I'm dead chuffed with - it's in primer now, and I think it looks even better than the original!) and dealing with a recalcitrent ARTF that hasn't really wanted to go together properly.

I have made a little progress tonight though on the Ballerina; I've designed and cut out the motor standoff box, and worked out how to ventilate the ESC compartment, which will be under my battery tray. I wanted to get all the mountings for the motor box dealt with before gluing the firewall in, should hopefully get all that done tomorrow now then I can start actually sticking the fuz together. All the formers are ready including modified F2 and F5, and I've got a plan in my head for the battery hatch (full length from F1 to F5).

My plan for the cowl is to make it removable; I'll mount the motor then build a frame around it bolted onto F1, then build the cowl around the frame. Hopefully if all goes to plan it'll then be easy to remove if necessary...

So, I'm a bit behind most of you others but should be done for the Ballet!

Pictures to follow!

Tomorrow looking like one of our rare flying days here in Yorkshire, but I'm out all day! ha, that's the way it goes.

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OK, so a bit of an update. Not as much done today as I'd hoped, but then I've been out doing other stuff! Like at our orchestra AGM all day and then painting my cowl.

I've finished cutting the mortices on the motor box and done a dry fit, and opened up a slot in F1 to allow airflow through the ESC compartment, which will be under the battery tray. My cowl will have an opening... somewhere... to allow the air in. Still thinking about what shape cowl I want to end up with.

Anyway, here are some pictures. One thing that occurred to me is that I've not so far seen any discussion on thrust lines - apologies if it's already in someone's thread and I've missed it. I have a slight worry that because it's not been mentioned, it's possible for a first-time builder to build everything straight (i.e. no down or right thrust) and thus have problems later... so my pictures below try to show what I've done. As I say, apologies if this has already been covered somewhere else.

Here's a picture of some of the parts of my motor box - I've just laid the motor mount on it for now so you can see where it goes.

components of the motor box

Here it is, dry fitted together and with the corners rounded a bit to fit better inside the cowl (and so that it looks a bit nicer...). I knocked a bit of the ply off opening up one of the mortices boo hoo; still, won't matter once it's all glued together.

motor box dry fitted together

The next two photos try to show how I've added the right thrust. I've offset the front panel of the motor box by 2°; looks more in these pictures, but honest that's all it is! Whether that's right for this model we'll see later, but it's what I've used before on a similar model so hopefully won't be far off. I'll add downthrust by adding washers on the top mounting bolts of the motor.

I've left the base off these pictures for clarity, but there'll be a bottom on this box, then if I *do* need to add any weights there's a nice compartment for them with little risk of them getting somewhere they shouldn't or moving around too much if they come loose.

top view showing right thrust offset

another view showing right thrust offset

and finally, a shot showing a trial fit onto the firewall. You can see the ventilation slot at the bottom here.

motor box trial fit to firewall

OK, done for tonight; assembly might finally start tomorrow!

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Precisely, John - my approach too (hazard a guess then fly it and see..). Rationale for raising it was just that I'd not so far seen it mentioned and it's perhaps not entirely obvious if you've not built anything before to make sure you build side and down thrust in! I've heard of models being built with totally square thrust lines - or even with left in!

John M - answer is a small woodworkers square, a bright light, some needle files and lots of patience!

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