Balsa bashing

[Enemy Ace]

Hello Jon, I grew up building "built up" wings but often lusted after the foam wings available in the UK and Europe. In my experience they do tend to build heavy..Truth be told the primary reason I requested the wood option was because I assume it would result in smaller packaging and thus cheaper shipping to USA where I live. However I am in the market for a yak or lavochkin regardless of wing construction.

[Brian Seymour]

Looking good Guy, much neater flaps and pockets than my one, the ProSkin lining the flap pocket should work better than the glass cloth that I used.

Having thrown some serious hours at the build this week I can't think what has taken so long.

Glassing the fuselage and knocking back the weave isn't a 5min job and was done in the following sequence: 1,sides of the turtle deck (including the lower tailplane fairing) and the wing fairings, 2, front sides, top of the turtle deck and top of the tailplane and fin fairing, 3,underside. It was a pretty simple job, the ball ache being knocking the weave back, I used the cheap cloth but, as there isn't a vast amount of surface area and therefore less resin is needed, I added a top coat of resin to help fill the weave but it still took a lot of buffing to level it.

The motor mount was made from a lite-ply base plate, lite-ply sides and a 6mm birch ply motor mounting plate. The base plate flexes a bit so a few balsa or spruce strips will be added as well as balsa doublers for the sides.

With the motor mounted the cowl was finished with a balsa nose ring which was shaped to blend the front of the cowl to the backplate of the spinner. The nose ring was made from 4 arcs of balsa so that there wouldn't be any end grain. The front of the nose ring was sanded to an even clearance from the spinner backplate. A skim of filler smoothed over the join line between the cowl and the nose ring. With all that done, shaped and, sanded, the cowl was glassed in one hit with a patchwork of off-cuts - a bit on the tight side but it all worked out albeit with a little more sanding effort required.

To get the fuselage ready for priming and finishing, a set of exhaust stack flanges were made and fitted. The flanges were made from the ladder of the dihedral braces, the wood is strong enough to take the knock and clouts of hanger handling. The flanges were spilt on the cowl join and the fairing is made from balsa.

In amongst the chaos of the fuselage, the flap and aileron hinges were glued. The shrouding on the ailerons does restrict the throws but I reckon that 22mm up and down will be plenty and the shrouding needed a little sanding to accommodate this. Fitting the flaps showed that there is still a bow in one of the trailing edges, interestingly, I used resin mixed with milled carbon on the side that hasn't bowed - maybe coincidental.

Motor mount:-

The glassed cowl curing on the radiator:-

Flaps and ailerons hinged:-

Exhaust stack flanges:-

Edited By Brian Seymour on 16/04/2016 10:32:24

[Jon H]

Hi EA, I can see what you mean about shipping. Foam wings are bigger without a doubt but these days they are not very heavy. I spoke with Richard about it and he said that selecting the specific type of foam as well as the glue for the sheeting and the sheeting itself can make a massive difference. As an example, the wings for Yaks you see here are only 6oz per panel as they come out of the box which is far from heavy.

Speaking of Yaks, I love your exhausts Brian. And your chin intake looks great too, I can see why you think you might be done in time for the concours!

I have been working away and finally have some photos. My jobs today were mostly tidying up the fairings and bit, tweaking the cowl and putting the spacers under the engine. Tomorrow I hope to get more done.

[Enemy Ace]

Sweet Hurricane Jon, another kit I'd buy...after the yak😍

[Jon H]

Thanks

I have done quite extensive modifications but most of them are very simple

[Brian Seymour]

Looking sweet! you saved up the stringers and fairing for nice double whammy. That's a particularly sweet sweep you've got on the leading edge fairing.

The club concours is a pretty good deadline for building, not that I've been doing this all my life but in my limited experience anything not finished by the concours doesn't get finished until August.

I got a couple of jobs done yesterday, the fuselage is primed but not knocked back - rain stopped play. and the flap and aileron servos, horn and, linkages are in and setup. The flaps come down 45deg and 70deg which, given their size, should be plenty and the ailerons swing 16mm down and 20mm up at full travel which is more than enough.

I also indulged in getting an idea of what green and brown shades to use. The dark earth shade that I've got is a cure for insomnia so I tried out various other brown shades. None of the brown shades look right on their own either too orangey, yellowy, or too light or too dark so I'm planning on adding some of the orangey brown, dark brown and a drop of white to spice up the dark earth. The green was simple, the green I used on the hoops on the Macchi with a drop of white.

Fuselage primed & ready for knocking (back before the rain):-

The wing with flaps and aileron link up and setup:-

My colour test pallette (Note! the prop in the picture isn't the one for Airfix kit):-

 

Edited By Brian Seymour on 17/04/2016 10:05:25

[Guy Pickett-Jones]

Looking very good Brian – As Jon says should be ready for the Clubs Concourse do you think? Spurred on by your comments about if it’s not done by then it won’t be done until August I am now concerned about the speed of my build!!! Also going back to Jon’s comments about these were meant to be a quick and fun build so I have now started to think about the finishing and covering of mine – and which way to go keeping time in mind. Having seen Graham’s being covered in Solar Film (or whichever exact make it was!) I am now thinking of maybe going this route. Graham’s was looking good, even though when I saw it last it wasn’t fully completed.

Although Jon liked the Camo version my initial paint scheme choice (below) could be done quite easily I believe using solar film, with the addition of decals etc for the details. (Brian I have ordered some of that decal paper you had to have a play with but the version you can print on an Inkjet then seal with a laminator)

Anyway progress today:

I wanted to get the cowling fitted so I could start to sand and shape the fuselage.

Firstly cut the Cowling to the correct size.

I then produced a (hard) balsa insert that fits into the cowl to maintain its shape at the base. On to this I glued the mounting blocks for the screws to fit the cowl to.

Using Brian’s trick I mixed up a small amount of epoxy and micro balloons to fill any gaps between the mounting blocks and cowl so I would get a nice, flush and secure fit.

The Cowl fixing plate was the glued to the fire wall.

Again taking notes from Brian’s build I drilled and countersunk the screw points on the mounting blocks. Gentle heating the screw heads I then tighten the countersunk screws in place forming the plastic cowl into the countersink holes giving a nice flush finish to the cowling without splitting the plastic of the cowl itself – all went well!

During the process I also had to cut an opening of for the head of the engine.

Fuselage is starting to look good now – starting to look like a real plane!!!

Next step if to join the wings together and fit them to the fuselage.

[Brian Seymour]

Very neat job on the cowl, she's coming on.

Knocking back the primer on the fuselage was time consuming but rewarding. The hatch and cowl only needed one session of priming and sanding, the rest of the fuselage took two sessions so I guess that the extra coat of resin did help to fill the weave. Overall there are a few imperfections but the rest is smooth as silk.

Whilst knocking back the primer on the fuselage I reassured myself that the fairing was feathered out as finely as it could be by cracking a chunk off one side and a swiping a gash in my hand with the other, both breakages were easily fixed with CA.

Having tinkered with paints I couldn't resist wafting a couple of coats of white to the underside surfaces, the colour scheme I'm doing has a white underside with brown and green camouflage on top.

Having had a little go at painting I thought I ought to get a couple of structural jobs done. The retract wells were reinforced with a milled carbon infused gel coat and 200gsm glass cloth. To bolster the mounting areas of the retract plate, a slot was filed behind the retract plate and filled with the carbon gel coat. The wheel wells and oleo channels were reinforced with a plain gel coat and 79gsm glass cloth.

The primed and buffed fuselage:-

Undersides sprayed with a couple of coats of white, three more coats should be plenty:-

 

Edited By Brian Seymour on 20/04/2016 00:32:58

[RICHARD WILLS]

I love what you're doing Brian . The Yak kit was designed for my local club as a hack and meant to be practical rather than perfect scale. However its flying qualities surprised us in both electric and IC form .

Our local lads fly them all the time but nobody has considered taking them to anywhere near this level.

When you see the speed and agility of the full size Yaks flown at Duxford , you realise what a contender they must have been in 1944. Its a slippery airframe but thanks to the models low wing loading and crafty wing section it has impeccable handling at both ends of the spectrum .

Its a very effective alternative to the modern ARTF foam warbird which of coarse are very good and require little time to get in the air , but do not offer the aerodynamic advantage of a stiff model or the durability .

Surprisingly my electric powered Yak weighed no more than my FMS 109 which made me wonder about the actual weight of EPO foam . I guess there is a reason why people have been making model planes from balsa for years.

I must say that Guy , Jon and yourself all build to very high standard so I feel very honoured to have my humble kit given the High Wycombe make over , Lots of colours to choose from , but having flown about five hundred or more flights on mine , I would advise as much colour as possible because they can do a pretty good dissapearing act !

Great work chaps

Richard

[RICHARD WILLS]

I love what you're doing Brian . The Yak kit was designed for my local club as a hack and meant to be practical rather than perfect scale. However its flying qualities surprised us in both electric and IC form .

Our local lads fly them all the time but nobody has considered taking them to anywhere near this level.

When you see the speed and agility of the full size Yaks flown at Duxford , you realise what a contender they must have been in 1944. Its a slippery airframe but thanks to the models low wing loading and crafty wing section it has impeccable handling at both ends of the spectrum .

Its a very effective alternative to the modern ARTF foam warbird which of coarse are very good and require little time to get in the air , but do not offer the aerodynamic advantage of a stiff model or the durability .

Surprisingly my electric powered Yak weighed no more than my FMS 109 which made me wonder about the actual weight of EPO foam . I guess there is a reason why people have been making model planes from balsa for years.

I must say that Guy , Jon and yourself all build to very high standard so I feel very honoured to have my humble kit given the High Wycombe make over , Lots of colours to choose from , but having flown about five hundred or more flights on mine , I would advise as much colour as possible because they can do a pretty good dissapearing act !

Great work chaps

Richard

[Jon H]

Thanks Richard

I have to confess to really enjoying my Hurricane build and all the additional work has been well worth it.

Speaking of work I have got my ailerons hinged and the servos and linkages sorted out. While I was in there I ran the wires for the landing lights and hooked them up to a micro switch that will operate off a mini servo and run off of the rx pack (subject to a current draw check!)

I think these should stand out!

[Brian Seymour]

Cheers Richard, we're having a great time on the build, the Yak design is really good and has enabled us to concentrate on dressing up our kits. The High Wycombe club has quite a few inspirational builders who are able give advise from their practical experience which has helped tremendously.

Jon, the ailerons and lights are ace, it looks like you've gone for scale spacing on the ribs.

A few of the non-painting jobs were finished off before getting the airbrush out again. The elevator servo, snake and control horn were installed and setup so that the snake and control horn could be painted with the rest of the model. The motor mount was beefed up with 6mm balsa doublers, the mount hasn't been reinstalled to see if it is now rigid enough but there is plenty of scope bring more wood to area if need be. Litho plate panels were added on top of the Solartex so that they would have a smoother finish. I was at loss as to how best to glue them on as there isn't much that sticks to Solartex, the penny finally dropped, Cover Grip was applied to the Solartex and the back of the litho plate panels and once that had dried they were simply ironed on. That went so well that I did the same for fuel caps on the wings.

I finally gave in to the urge to plug the airbrush in and gave the top of the wings a coat of the green and brown. I'm not entirely convinced with the shades but it doesn't take too much effort to buff the paint off. The paint goes on thinly so takes a few coats before the colour develops, my current thinking is that the green is a little on the dark side and brown is bit too orange but I'll decide once the primer no longer shows through.

Elevator horn & snake and a litho plate panel.

Fuel caps:-

The photo is a bit blurry but left wing (on the right of the picture) has had 2 coats of brown and has come out a little less orangey so it's not beyond hope.

[Guy Pickett-Jones]

Thanks for the comments Richard - Has been an enjoyable build to date.

Lights looking good Jon!

Expecting the Maiden very soon Brian

No Pictures but my wings have now be joined which means I can start looking at installing the retracts. Steady progress but really want to try and get this finished in the next few weeks as other projects are starting to back up!!!

[Jon H]

I have been flat out and too busy to take photos!

So far i have covered the elevator and rudder and managed to glass the wings and forward fuselage. When i get home i will quickly reinstall the engine and other bits so i can bring it to the concourse.

Will you bring yours guy? we should all enter even if they are not finished.

[Guy Pickett-Jones]

Yes planning on bringing mine down - hope everyone from the build group will bring theirs as well - will be good to see all of them together!

[Brian Seymour]

It will be pretty good for those not partaking in the build as we should have a nice example of the build at each of the key stages.

 

She's not too far off, a bit of; finishing, undercarriage tweaking and, linking the rudder to the servo are pretty much all there is between her and the sky!

The weekend was more or less an airbrushing marathon - life's tough round here!! I changed my mind on the shades of green brown several times throughout the painting and ended up with a somewhat strange effect on the wings, I'm not entirely sure whether or not I like it but at the moment I don't dislike it. The stars and squadron numbers had to be painted on the fuselage as I didn't rate my chances of applying the decals to the stringered Solartex, neither did I rate my chances of getting a colour match to the decals and so the stars on the wings and fin were also painted.

Painting was right old game really, the green(s) needed coat after coat to get them to go opaque and the brown slightly less, add to that some of the paint mixes separated resulting a slightly fogged/bloomed areas. The fogging was taken care of by wafting very fine coats on but it does still show through in places. The other irritation was a blockage clearing as I was applying the white to the fuselage under the tailplane, this splattered down the side of the fuselage - luckily the big star and numbers don't make it too obvious.

A couple of coats of a 1:2 mix of matting agent and Poly-C were sprayed on to protect and seal the paint, this really did bring out the different shades of green and brown and just how unevenly I sprayed them!

I guess that finish will be Marmite but once I add panel lines and weathering it might just blend in nicely!

Basic paintwork:-

A star or two are born:-

Mate... I know that there are better examples but that's as good as it gets from me and I can't wait to send her skywards!:-

 

Edited By Brian Seymour on 25/04/2016 14:06:51

Edited By Brian Seymour on 25/04/2016 14:16:06

[Jon H]

looks ace from here! and anyway, the russian ones had far from perfect paint so i wouldnt be too stressed!

[Jon H]

Despite my phone camera's dreadful low light performance here are some shots of my hurricane all assembled

[Brian Seymour]

Photos from the concours:-

 

 

 

 

Edited By Brian Seymour on 26/04/2016 09:05:51

[Simon Knight]

Evening gents. Seeing your progress has made me realise I have come to a halt. The reason is the gear. I don't have spares sitting around and wondered can I use straight wire in retracts or does it have to have a coil in it? I have tried bending the 4mm wire and am really struggling. Are your Oleos 4mm pins or have you used 5mm with a little shaving to fit the retracts servo units? Tips gratefully received to try and make progress...

[Jon H]

straight wire will do in a pinch. you could buy a wire bender but I cant recall how pricey they are. that or get some oleos from hk

[Guy Pickett-Jones]

Hi Simon,

Can't really add much to Jon's comments in terms of what to do, plus this will be my first time installing retracts as well!

The retract units I'm using are the larger version that match the ply plates with the kit (off a model shop on ebay) they have a 5mm pin - went for these as I am planning to use HK oleo's which mostly seem to have 5mm pins themselves.

I have made wire legs in the past and yes bending the 4mm piano wire is not easy especially putting a coil in it - lucky at that time I had access to a workshop and actually made a bending tool to do the job!

Guy

[Brian Seymour]

Simon, the retracts that I have used take a 4mm pin and the oleos take a 5mm pin so I have used a 4mm pin and used a length of aluminium tube with a 4mm id and 5mm od in the oleo.

I can't comment on coiling piano wire, I haven't been able to do it particularly well even with a decent wire bender, I would buy ready coiled legs - cheaper than buying a decent wire bender.

[Brian Seymour]

On the subject of bending music wire, I have had three evenings faffing around trying to get the legs to look reasonable and retract without stalling the retract. My first attempts left the legs looking a bit bandy and awkward, my solution was the result of a few monkeys and typewriters efforts, I can't explain it but the pictures might shed light on what's going on.

I applied a several little tricks that have worked on my other modes: flat the link pins where the grub screws bite, flat the front faces of the grub screws and use a stack of three bevel washers under the heads of the front retract screws.

Lazy 'Z' bend to offset the retract leg:-

Retracted:-

Bevel washer stack:-

[onetenor]

By bevel washers do you mean countersink cups?