Tim Hooper's Cygnet

[Gothiquity]

Well like so many of us, im unable to fly, so to pass the time im picking up a project from my bench. Ive always liked the Hawker Cygnet since seeing it static at Cosford and more recently the two fine equally static examples at Shuttleworth, and thought one day it would be great to have a RC one of my own.

Well that day starts today, I have the Tim Hooper plan, and a healthy stock of balsa n glue, so time to start.

I purchased the plan , n laser cut kit from SLEC a few years ago, and a recent search shows its no longer listed so my apologies if anyone starts looking for it.

Starting as Mr Hooper did back in 2010 I'm setting out the 1/16 balsa strip laminates to make up the all flying rudder, elevator and wing tips.

starting with the rudder

Nothing too exciting, took a while to get the balsa to bend without cracking , but got there in the end. Think it requires far more patience than i anticipated .

Left the above to dry for a couple of days then started filling out the core structural elements of the rudder

Made a few very minor changes making some notches for the 1/4 SQ balsa to go into. As Tim said in his build, if this plane goes over on a bad landing the rudder will take the brunt of the impact, so every little trick to add some strengh without weight must be a good thing.

Still to add the 1/8 SQ faux ribs and some extra 1/8 sheet.

Goth

Edited By Gothiquity on 29/03/2020 22:20:56

Edited By Gothiquity on 29/03/2020 22:21:44

[Timo Starkloff]

Nice aeroplane

I've been to Cosford last year and saw the tiny Cygnet, too. A good book with many great photographs including the Cygnet is "The Lympne Trials - Searching for an ideal Light Plane"

https://www.amazon.co.uk/Lympne-Trials-Searching-Ideal-Light/dp/1840335734

Good luck with your build, Timo

[Tim Hooper]

Hi Goth!

Nice to see a Cygnet on the boards!

Did you soak the balsa strips for a few minutes before you bent them into shape?

Incidentally, I still have the original model safe and sound. It doesn't get much airtime but it had a couple of flights last autumn.

Tim

[Gothiquity]

Cheers Timo,

Not aware of that book, so i'll get that added to my reference list, looks very useful.

 

Hello Tim,

I hope I can come close to your level of workmanship. Yes I did soak the balsa beforehand, however on my first attempt I hadn't soaked it long enough, so yes got cracks. Finally got there though and worthwhile persevering with.

Glad your cygnet is stilll going. Can i ask one question , what type of hinge did you use on the rudder, i am considering either robart style or flat pin hinges.

 

Goth

Edited By Gothiquity on 31/03/2020 21:54:56

[Gothiquity]

Ok so slow progress , this work thing gets in the way and the hangar(garage) is a bit nippy in the evening.

Rudder is now roughly done in terms of adding wood, just need to get it down to the aerofoil shape.

Thought i'd also share with you the rough stages i go through to get to the above

photocopy of part of the plan that needs laminations, paste onto foamboard and trim to required size, add laminations, then wait a few days add some bits n bobs and hopefully one all flying rudder for the Cygnet.

Also made a start on the next part, the main (upper) wings

Wing tips are made in the same way as the rudder with 16th balsa laminations, this time stepped in width to build up to match the spars.

thats it for now.

Edited By Gothiquity on 31/03/2020 21:56:29

[Tim Hooper]

Posted by Gothiquity on 31/03/2020 21:43:15:

Glad your cygnet is stilll going. Can i ask one question , what type of hinge did you use on the rudder, i am considering either robart style or flat pin hinges

Goth

Edited By Gothiquity on 31/03/2020 21:54:56

Just checked my photos (it's too cold to go out to the garage) and I used a pair of heavy-duty pin hinges.

I'm assuming you've found my original build thread?

**LINK**

Tim

[Gothiquity]

Cheers Tim, yes have read your original build log, must confess didnt see the hinging before, have seen it now. Pin hinges it is then.

Yes too cold for garages.

Thanks

Goth

[Gothiquity]

So a productive day today, got one main wing laid out.

I must confess this build demands patience and attention to detail. Noticed what i think is an error on the plan relating to the size of the LE on my plan its noted as 3/8ths sq, and i had alreday put a pice of that size in and was just dry fiting ribs etc to see how it would all go together, couldnt figure out how the cap strips lower and upper would fit over the rib and below the level of the LE, then saw the side view amd noticed that the LE is much bigger, a few measurememnst later and a rumage through my wood pile and i have 3/8ths by 11/16ths as the LE which works much better now.

 

some images of my progress

 

Basic layout showing lower cap strips , wing tip, and TE

main spars and correct dimemnsion LE added, note carbon fibre joiners safely epoxied in place.

 

all main ribs now added, next step once dry to sand down to profile before adding top cap strips.

 

Goth

Edited By Gothiquity on 04/04/2020 19:28:05

[Tim Hooper]

Good neat building!

I did wonder why the Cygnet had such huge ailerons, until I saw a picture of it with its wings folded back for storage/towing. The ailerons need to to move out of each others way as the wings fold back back alongside the fuselage.

Similarly, the rear portion of the upper centre section folds forwards for the same reason.

tim

 

Edited By Tim Hooper on 04/04/2020 20:49:49

[Tim Hooper]

Full sized walk around

Tim

[Timo Starkloff]

Part of the Lympne Trials was passing a gate or frame with certain dimensions, therefore the plane had to be transportable. Nice story is about one of them landing a few miles away from the contest field. Wings folded the plane was carried back along the roads. Light weight helped of course, too

Timo

[Gothiquity]

HI Tim

Thanks for the comment and the ref pictures, very useful. I did manage to crawl over the one at Cosford a few years back after one of thier very friendly warders let me over the fence. Not been able to find my pics, so appreciate your link.

Did wonder about trying folding wings, before i came to my senses and thought better of it.

think i'll try to emulate the look of G-EBJI.

Goth

[Gothiquity]

Another fairly productive day,

Upper cap strips applied, riblets applied. Just final aerofoil shaping to do.

one wing panel down three more to go.

Really enjoying the build so far, challenging without being crazy. Just need to pay attention and check Tim's excelent build log which show how parts should look, as well as the plan. Using both gives a good all round view.

one thing i have noticed is depsite knowing the dimensions of the finsihed model, just the one wing on its own , looks big. Tend to think that the numbers dont always mean much till its sat on your bench.

Goth

[Gothiquity]

Decided to take a break from wings , started on the elevatort and horizontal stab

pretty straight forwrads stuff, well so far. This is just a dry fit so far as i cuit pieces to fit.

Goth

[Gothiquity]

Ok so more progress made today as well as discovering a mistake I made on the main wing.

I had the wing tips made from balsa laminates however i had not used wide enough strips , so am now in the process of making wider ones, they need to match the LE and step down from there. so ive opted for 5/8ths, then 1/2 then 3/8ths two of each to make the 6 strips needed. And with my new found patience and technique to bend balsa i made both wing tips without any cracks. 

I have also ran out of 6mm carbon fibre rod so waiting for a deilvery which may take a while, oh well, cracking on with the fuselage.

Got my plan copied and laid out ready together with my supply of hard and medium 1/4inch SQ balsa.

Im suspicious as it seemed to go together fairly easily, which makes me belive I've gone wrong though checking my results against Tim's they look roughly the same. Am allowing the glue to dry off before starting the other fuselage frame.

But so far looking good. this is one very impressive build, and im forcing myself to take the time to get it right.

The fruits of my labour today , the wooden meter rule isnt used for measuring instead I use it to keep the top longeron straight. My plan is to build the second frame on top of the first to ensure they are identical.

Goth

 

Edited By Gothiquity on 10/04/2020 21:31:30

Edited By Gothiquity on 10/04/2020 21:31:59

Edited By Gothiquity on 10/04/2020 21:32:47

[Gothiquity]

Ok so made plenty of progress over the BH weekend

Both sides of fuselage were completed, all straight forwards stuff really.

Set second frame up dircetly on top of first to avoid any major differences

May not look like it but this is both sides on top of each other , clamps in place to hold 1/4 SQ hard balsa longeron as it goes round main curve that will be for lower wing and undercarrigage.

Once glue was dry I took a moment to check them both over

Yep looks good to me.

Next was laying out the formers, the ones in my laser cut kit were a tad warped, probaby warped from my own fault of poor storage , so made new ones.

laying up on side 1 and keeping things square

Then adding the seconf frame, Tim helpfully points out in his build guide that is best to turn the frames upside down and join them that way, seems like a good approach.

Used elastic bands to hold thigs tiogether, so will leave that there gluing for now.

Said it before but worth saying agin , The Hawker Cygnet is a beautiful little aircraft full of charm and character. To ensure i dont make a monumental mistake Im taking my time, to get things as right as i can. No idea how long it will to take to get this one finaly airborne but it will be worth the wait and im enjoying every moment of the build, challenging without being frustrating.

Cheers to Tim for a great plan of a lovely little plane.

Goth

[Tim Hooper]

Thanks Goth!

It's a pleasure to see this model grow on your board so neatly.

Tim

[Gothiquity]

Ok so made some progress then a minor hiccup.

First cracking on with the cross members, again nothing taxing here , just 1/4 SQ balsa cut and chamfered to fit well and keep frames square.

and another view of the work so far

So following Tim's build log came the part I wasn't looking forwards to, to bring the two sides of the frame together at the rear you need to split the 4 longerons and 2 posts in half from the last cross member. I fitted a new blade and cut in

Actually easier than i thought , next is to bend them together and glue everything back together.

looks messy but i had manged to get it straight on the line.

Then came the mistake i left the hangar for the night.

Next morning was not pretty, at some point in the evenig / night one side of the frame cracked partailly whilst the glue was still wet and the strain on the other side twisted the tail over.

A few strong cups of tea later i came up with a plan of action

To protect the partially cracked frame I opted to create two 1/4 sheet hard balsa formers to match the tail shape and used these to coax the frames around, also removed the last two cross beams

end on view looking pretty straight ,

So i think i managed to rescue it, yes i know the stern posts do not meet, however i have a plan for that too, to provide some meat for the hinges to go into I will remove whats left of the stern posts and install a solid piece of hard balsa probably 1/2 inch then blend the curve into it, should look seamless once im done, just have to accept a slight weight penalty or adjustment to where i position things in the model to get CoG.

Finsihed off the night by installing F1

Thankfully uneventful. I used the oversized planks of balsa to help keep the sides even and prevent uneven bending , wish I had done that last night, oh well. Chalk it down to experience,

Goth.

[stu knowles]

Really nice building skill on show here. Thanks for posting, I loom forward to seeing it develop

stu k

[Tim Hooper]

Good save!

Tim

[Gothiquity]

Onwards and not quite upwards yet. 3 more weeks of lockdown, will the cygnet be ready ( unlikley, it deserves time to be taken with it ). I'll be happy if both sets of wings are done.

So finished off infilling the nose section of the frame with 1/4 sheet and triangle bracing

 

Pretty happy with how well that went together , then attacked the diagonal bracing in the rear fuselage

 

Its really impressive just how strong and light this fuselage is, first time Ive actually done this type of open structure, usually the planes i build have sheet slab fuselages. Was concerned this may be fragile and prone to breaking , but after trying to flex it the thing is rock solid.

Following my earlier near miss with the stern post Ive now added the 1/8 sheet balsa outer sheets and some scrap balsa inside to provide some meat for the hinges

 

Again not too unhappy with how that works, have already tried the rudder against it and it sesm to fit ok for sizing.

Due to an earlier issue with the one main wing Ive done , im now waiting ( like most modellers i suspect) for more balsa to arrive. So whilst im waiting for that to arrive I turned my attention to the brass work.

 So the above represents all the rigging plates for the cygnet , I have searched the net and forums and havent found out what thickness brass sheet should be used for this type of application. I used what i happened to have in my shed. Seems good enough for now. Also did the PCB board rudder pull pull horn, two more of these to make for the pull pull elevator.

thanks for following

Goth

 

Edited By Gothiquity on 18/04/2020 21:03:42

[Tim Hooper]

Wonderful stuff, Goth!

Tim

[Gothiquity]

Not much done , managed to get the under carriage fettled, , never enjoy wire bending , always seems to go a tad wonky.

Followed Tim's lead and used a jig block to set it up, seems to have worked ok

Was initially too agressive on the 10SWG wire and actually snapped it mid bend , thankfully I had enough spare to remake it. First time soldering brass and making brass saddle clamps.

Must invest in one of those wire bending tools.

Dont have any of those scale looking hair bungees to hand either, just my luck my wife doesnt wear em.

Learning so much on this build it really is an eye opener , and its making me realise hwo something that loosk complex can actually be straight forwards if you take your time.

Still no wood yet so will tackle the cabane struts next .

happy modelling

 

Goth

 

 

 

Edited By Gothiquity on 21/04/2020 21:06:01

[Gothiquity]

Well the wood finally turned up courtesy of SLEC & The Balsa Cabin. So i revisted the main wings again.

I had made one main wing initaily however I had made a few mistakes and whilst the end product looked ok, and would probably had worked I wasnt happy with it.

So here are the mistakes I made and the solution I have now used

Initaily i took a copy of the wing from the plan to work on , which worked great unitil after finishing the left wing and trying to create a mirror copy I could not get the size to match. Solution I had read online about sticking the plan on a window and tracing a mirror copy, however I opted to buy some velum ( semi transparent paper) and printed onto that, so one plane for the wing and i just flip it over for the opposite side guarunteed same size both sides.

Wing Tip, I thought I had been really clever measuring the end of the wing spar and making the maximum step size in the wing laminations the same, quickly realised when i offered my wing tip up to the leading edge that i had got it very wrong. Solution obvious really but study the build log , see how it looks on the prototype and make sure mine matches, in this case the plan has the wrong LE dimensions on it, but I figured out the right one using the front wing rib and riblets as a guauge for the LE suize then used that as my wing tip guide.

The old age measure twice cut once springs to mind.

When building the wing you are supposed to use a 1/4 inch balsa piece for the mid rib section where the interplane struts attach, it is marked on the plan, but I goofed and missed it instead using a 3/32 piece, when I realised I tried shimming it with an additional 1/16th either side, and it was obvioulsy close, but I didnt like fudging it. Solution pay attention to the plan

Capping strips , never applied capping strips, (i know never lived have I) so searched online for how to do it.

Found a lovely video from a Mr Danny Fenton showing the exact way to fit a cap strip using CA glue .So I tried. The problem was the capping strips are full chord on the cygnet and in Danny's video he only fits partial ones. The CA glue I was using was the thin stuff and it had gone off before I had fitted the full cap. Solution i used wood glue, gave me more time to adjust and fit.

So quite a catalogue of issues, none of them probably a show stopper in real terms, although different sized main wings could have had some intersting effects on latereal CoG and manouvreing. However part of the challenge of this build for me is to get it as right as i can, no shortcuts, no fudging.

I accept that their are many ways to achieve the end goal , lots of different methods and I guess what im learnig here is to find the method that works for me , given the tools and skills I have. Some of you reading this may disagree with my chosen solutioms, but this is just what worked for me this time, next build around I may need to adopt a different method or shock horror I may actually improve my skills.

Anyway the main wing second attempt is now done, photos below.

So yes, my mistakes cost me time and a little money and a few more grey hairs, however im happier with the end result.

Thanks for following this build so far , stay safe and happy modelling.

Goth

[Christopher Coldbeck]

Hi

ive recently acquired one of these magnificent planes and restored it back to flying condition.

im just about to fit a f/s engine. Can anyone tell me where the C of G is for this plane so I can balance her ready for maiden?

Edited By David Ashby - Moderator on 23/07/2020 20:01:57