An idiot's guide to building a Barnstormer

[Nigel Day]

Thanks Plummet.

I want to build both halves in parallel. That way I can be gluing bits together on one half whilst the other is drying.

I also don't trust myself to remember that I'm building a mirror image so I'm sure I'd stick something on the wrong way or cut/shape something similarly.

[Nigel Day]

And just my luck, my replacement ESC (read previous posting(s) for the story) has just been shipped by HobbyKing - just as I'm about to go on hols. If it doesn't arrive by Saturday morning I'll just have to hope that ParcelForce leave it with a neighbour otherwise it's a trip to the local depot.

[Nev]

Nice building job there Nigel, definitely honing the building skills.

[Plummet]

Posted by Nigel Day on 06/06/2014 08:37:30:

Thanks Plummet.

I want to build both halves in parallel. That way I can be gluing bits together on one half whilst the other is drying.

I also don't trust myself to remember that I'm building a mirror image so I'm sure I'd stick something on the wrong way or cut/shape something similarly.

Nigel,

Be positive - you are supposed to learn from your mistakes. It would be better to learn from other's mistakes, but in my experience that is too much to hope for.

What is it they say? No-one should be sacked for making a mistake - only for making the same mistake twice.

(I can say that - I have retired.)

Plummet

[Nigel Day]

Don't worry Plummet, I'm very positive. Having been a boy scout, my motto is 'be prepared' and I try to avoid opportunities for me to make mistakes where I can - however unlikely.

Thanks Nev. I'm learning a lot. Miles from the quality of the master builders but I can see how to improve with every wing, joint and linkage I do. This Chippie malarky should help a lot too.

[Nigel Day]

Well it's been 4 weeks since I last posted an update here.

No, I haven't given up - nor spent all my waking hours flying. I've just been a bit lazy and doing a bit of work around the garden and entertaining friends.

Since the last exciting instalment I've rubbed everything down as promised and started covering. I've already posted a piccie of my colour scheme so you can see what I'm hoping to end up with.

Like a lot of the bits for this model, I'm having to think about the order and the way in which I cover them. The tailplane will be covered in two different colours so I'm covering the fin and the wing separately and then joining them. I'm also covering the front 'lump' (that sits on the top of the fuselage in front of the pilot) and the rear headrest etc prior to adding them to the fuse.

The tailwing turned out OK

and I even remembered to leave the centre section top and bottom uncovered so the bits would stick together securely.

I treated myself to a Prolux sealing iron with digital thermometer. It made the job a lot easier than the travel iron I used to cover my first model (Junior 60).

The instructions provided with the Profilm rolls are very good and I re-read three articles I've picked up from earlier RCME articles I picked up on-line. The iron was used at 100 degrees to tack and to smooth down and a hot air gun (Black and Decker variable heat/power) to shrink and seal with a cloth glove to smooth and firm down. I wish I'd had another couple of arms though as I found it very difficult to hold the wing and the air gun and then stretch the film. You can see that the ends of the wing aren't going to win any medals. For the next job though I'm going to try holding the air gun in a clamp of some sort freeing up both hands.

Some care will be needed!

I had planned to only partially iron the tailwing covering so I could attach the covered elevator and add the cocktail sticks through the hinges. Guess who forgot? I now need to decide whether to carry on as before and simply patch the resulting holes in the covering or to just use epoxy to glue the hinges in.

I'm not sure what bit of equipment the 'lump' at the front is representing but, following Tony Bennett's problems with cooling I though I'd use it as an air intake. The front has been made hollow and I'll take a small chunk out of the top of the fuse where it will sit. Along with deliberate gap around the prop spinner, this should get enough air into the ESC & battery compartments.

On with the fin and rudder next.

[john stones 1 - Moderator]

Never used pegs myself Nigel, i just make sure to push plenty epoxy into slot (thin bit of piano wire) never had a failure

John

[cymaz]

Glad to see you have returned to the build

[AlexJ]

Hi Nigel,

With regard to pegging the hinges, you could drill blind holes from underneath, glue in the pegs, making sure that they are not proud of the surface. To cover, you can use a hole punch to create some nice little discs of covering.

I must confess that I have not tried it but in my imagination it might work.

Regards

Alex

[Danny Fenton]

I use that fabriccy type hinge material that really wicks up thin CA and use that. I probably shouldn't say this but I don't pin my hinges. But then I have never used epoxy for this purpose either....
Good to see you cracking on
Cheers
Danny

[Nigel Day]

Thanks Cymaz.

Thanks John, Alex. I did a bit of both in the end. I stuck (!) with epoxy for the elevator but went with the belt and braces cocktail stick approach for the rudder.

Thanks Danny. I've got a few fabriccy hinges but they seemed a bit flimsy and I struggled a bit getting them into the wood. I'll try again at some point and prepare slightly bigger slits.

So, dum de dum de dum de dum, dum de dum de dum dum (imagine the Archers theme music here if you would), we return to rural Cornwall where country bumpkin Nigel is wending his merry way with his model........

For the rudder I covered it completely after putting the hinge in place as for the tailplane wing (with cocktail sticks). I then covered the fin, but cut the film so that I could leave the formers, where the hinges fitted into, clear temporarily. I then fitted the hinges, rubbed the area down then ironed the rest of the film down. For good measure I then ironed on a bit more film to cover the areas cut for the hinging. Not the most elegant but it's worked OK. I think I might try Alex's idea next time though. I seem to remember reading about this in an RCME article somewhere but I'm blowed if I can find it.

So the fine ended up like this:

And then I needed to fit the tailwheel before joining the fine to the tailplane.

Rather than find suitable wire and a wheel and then solder on the 'endstop', I figured that I'd cheat and buy a tailwheel assembly. The one I picked had a bick bit of plastic to go under the fin and a long bit of wire. Too long for here because of the cutout for the elevator. However, the basics were there.

The method I've gone with was to remove the plastic gubbins, shorten the wire and bend it to fit around the base of the fin so:

There's a channel cut out around the base of the fin to hide and hold the wire

And it fits together so:

I'm now off to firm up the channel with a tiny bit of silk and cyano and then glue the roughed up wire tailwheel assembly with epoxy.

Hopefully when I add the next rural instalment of 'Nigel bashes balsa (until it screams for mercy)' it'll be nicely cured, covered with film and the fin will be sitting squarely on the tailwing.

Stay tuned......

[Nigel Day]

So, the tailplane assembly is all in place and nice and square......

The rest of the fuse has been covered and I've continued to learn along the way.

Cedric Courageous/Terry Thomas/Dick Dastardly looks eager for his first flight. Little does he know that it'll probably be his last!

I mentioned that I'd make the front fairing into a mini air intake. I've no idea how much help it'll be but what the heck.

I just need to centre the servos and align the rudder and elevator and the fuse will be done. Oh, and I need to add the bits of tin to the bottom corners of the removable top cowl bits so they'll stick to the molybdenum magnets I've used. I would have used kryptonite but we have a family weakness to that.

The covering was both interesting and enjoyable. Whilst it'll never win any best in class prizes, it's a good step on from my first attempt on the Junior 60. I had problems there with the curved ends to the wings and around the nose.

Before starting this time I treated myself to a Prolux digital iron (with sock) and a Black & Decker variable power heat gun. The B&D is a treat to use and the main reason my covering has improved. Stretching the film around the corners is MUCH easier using that and gloves. I still need to use new blades for cutting the film (or one of the various cheap and simple cutting tools available) and I need to work on the overlaps, especially over compound curves. I can get the main bit of the curve fine. It's the bit that's left when I cut of the excess that I struggle with. How do I stretch the 1/2 cm or so left so that it's flat? I can probably improve on the first piece by cutting the excess very close to the 'stuck' bit, but what about the excess left on the second, overlap bit?

You might have read about my 'fun' with ESCs I've been having in another thread. Another is on it's way and I've got plenty of help and advice for testing the second one again and connecting it all up correctly. Maybe by the next time I post I'll have all my bits (ooh err matron!) and will have the motor and electric gubbins sorted.

Now it's the wings.

I'll be building these in parallel as I find it easier and quicker this way. One of them will be a 'right-hand' and the other a 'left-hand', don't worry.

More next time.

[john stones 1 - Moderator]

That's looking good Nigel doing curves is not easy for anyone, but good tools and patience help a lot. Get a move on though you're missing some good flying weather

John

[Nigel Day]

Thanks John.

I'm cracking on with the wings:

This is the easy bit though and I am doing them in parallel.

The trailing edge, spars and ribs were all pinned onto the board. Then I lifted each rib and glued them to the trailing edge with PVA. I then immediately line up each rib correctly and thin cyano-ed them one by one. Once one wing was done I repeated the process with the second.

I've left the root rib off until I know what dihedral the wings should be at. The plan says 4 degrees - but that's without ailerons. I guess I could have no d-h (as Tony B did) I guess but I suspect that I should have a couple of degrees. The cabanes will be configured for 4 but I'll be able to handle that with a sliver of wood where the fixing points sit under each wing.

Anyone got any thoughts? If not, I'll go with 2 degrees and calculate how much the wingtips should be off the board.

Next up will be the webbing, capping, leading edge, leading edge sheeting and removal of the aileron pieces.

(Thanks John, might stop some of the guffaws)

Edited By Nigel Day on 24/07/2014 20:02:41

[john stones 1 - Moderator]

I don't think it's that big a deal Nigel, go with what feels right to you, I like making wings

John

p.s. edit it before someone tells you it's dihedral not incidence

[Nigel Day]

In that case I could take the easy way out and have none.

Bear in mind though that this will probably be my first trainer.

[john stones 1 - Moderator]

Have it set up gentle Nigel, I assume you'll have an instructor..yes ?

But whichever, do what feels right to you, flat wings are easy though

John

[jolliffee]

Hi Nigel, I've got dihedral on mine - I think it will be very twitchy without it - I took advice from DB.

[Colin Leighfield]

I think I would concur with that one!

[Nigel Day]

Instructor? I don't even have a club here! I'll be teaching myself on a nice corner of Bodmin Moor. There might be one or two others available to provide a bit of advice and guidance but I haven't made their acquaintance yet.

Sounds as though I should go for some dihedral then. The question is a bit or the full monty (4 degrees)?

[Martian]

Hi Nigel I halved the dihedral on mine as I understand it the full 4% will make the ailerons nigh on ineffective

[Nigel Day]

Hmm, I remember reading that somewhere Martin.

Ah well, I think that I'll just have to assume that I'm not a complete numpty when it comes to flying and build in little or no dihedral.

I'll be teaching myself but after spending a bit of time on the Phoenix flight sim. I'll be taking it easy for a good while so, baring bad luck, I'll get chance to get used to it and then benefit from the greater responsiveness (less stability) afforded by the reduced/minimal/lack of dihedral.

[Martyn K]

My experience with high wing trainers and dihedral is that you will need to learn to use the rudder. While under power and with the model flying at a reasonable speed, the ailerons will be OK. However as you slow down, the ailerons will become less effective and the rudder more so. It could complicate things, however, if in doubt stick with the designers recommendations. At the end of the day, if you panic, just let the sticks go and the model should stabilise itself.

However, I really recommend that you find a club with an airstrip. Taking off and landing on moorland is not easy - I speak from experience as I have flown R/C power models on moorland outside Rochdale when I was (much) younger.

Good luck

Martyn

[Nigel Day]

Thanks Martyn.

There aren't too many clubs, let alone airstrips close to me here. My nearest clubs are both 25 miles away and I don't think that either has an airstrip.

The good thing is that the area of moorland we're talking about is heavily grazed - and so closely cropped. The downside of that is the regular bits of sheep and horse poo.

[cymaz]

Nigel, come and visit us

 

Here

I live in PL31 so you're very welcome to see me.

 

 

Edited By cymaz on 25/07/2014 17:40:32