By continuing to use this site, you agree to our use of cookies. Find out more
Forum sponsored by:
Forum sponsored by CML

Tim Hooper's Cygnet

Building the Hawker Cygnet from Tim Hooper plan

All Topics | Latest Posts

Search for:  in Thread Title in  
Gothiquity18/04/2020 20:56:56
49 forum posts
84 photos

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

thc f16.jpg

thc f17.jpg

 

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

 

thc f18.jpg

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

 

thc f19.jpg

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.

thc h1.jpg 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 Hooper18/04/2020 22:25:08
avatar
2911 forum posts
2412 photos

Wonderful stuff, Goth!

Tim

Gothiquity21/04/2020 21:05:07
49 forum posts
84 photos

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

thc u1.jpg

thc u2.jpg

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

Gothiquity25/04/2020 21:55:16
49 forum posts
84 photos

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.

thc w1a.jpg

thc w2a.jpg

thc w3a.jpg

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 Coldbeck23/07/2020 19:25:41
1 forum posts

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

Tim Hooper23/07/2020 21:52:34
avatar
2911 forum posts
2412 photos

Christopher,

I've checked the plan, and it's 85mm behind the LE of the upper wing.

Tim

Vecchio Austriaco24/07/2020 09:12:26
avatar
1515 forum posts
728 photos

Great stuff Goth, also I have plan and material set at home since a few years. I got in trouble with the balsa laminate, made the rudder minimum 3 times, those stripes where always breaking. I even used ammonia water to make them more bendy, no chance. Well a few years older and more time, probably I give it a go again. Will probably go down to 1mm balsa, needs more strips but probably bends easier...

VA

Andy Stephenson25/07/2020 15:21:50
217 forum posts
36 photos

Vecchio,

Try 1/32" thick balsa and you won't have any trouble especially if you soak the strips in PVA/aliphatic, no need of ammonia. I make my curved laminates around an MDF former covered in Sellotape to avoid sticking. Cutting them wider than necessary then sanding them to correct width after the glue has hardened. This is process hasn't failed for me even the first time I tried it.

Andy.

Gothiquity08/08/2020 22:15:34
49 forum posts
84 photos

Hi all, sorry for the long abscence, bereavement. Fair to say my mind was not on the task at hand back now though and picking modelling back up. So Vecchio, welcome aboard, its a brilliant build, challenging for me, as its a lot of stuff i haven't done before but i wanted to build the cygnet, so im finding my way through it.

I found out lots of ways of creating laminates from balsa strips, here is what worked for me.

Soaking the strips in hot water for a good 5 minutes a use a big plastic bottle so i can immerse the strips fully. Ive used 1/16 thick balsa with no issue. Once soaked i keep all the strips together as a bunch, as i found doing them one at a time they could still snap. Pin the strips down at one end of the shape or former you are using then gently ease the strips around it , i found using a small diameter tail wheel really handy as it meant i couldn't exert too much pressure. As you slowly get the strips to form the required shape just clamp in place using small blocks of scarp balsa ten leave to dry. I don't use glue at this stage , once the strips are dry i then take them off the former and reapply individually using glue and as the strips are already pre bent it makes the job much easier. As Andy said cover the edge of your former, ( I used foam board) in sellotape as it allows the glued strips to part company with the former really easily. I appreciate this is long winded way of doing it , but it works for me.

Have made some progress with the cygnet got the wings mounted to the fuselage and am now working on the struts. Tim has designed a cracking model, just hope i can do it justice. Pics to follow shortly. Just waiting on more brass sheet for the fixings.

Goth

Gothiquity30/08/2020 22:23:03
49 forum posts
84 photos

All

ok slow progress, started back on the fuselage , after getting the wings there or thereabouts.

Added the formers, stringers and then started the front planking.

rear turtledeck formers.jpg

rear turtledeck stringers.jpg

Never done any planking before so after a fair amount of searching and reading discovered there were more methods than I could take in, and some seemed fairly assertive that their method was the only way to do it.

I chose a method which seemed the most common sense approach to me and cut and stuck the 1/8 x 1/4 planks down.

front deck formers and planking.jpg

front planking.jpg

Don't think I did too bad. I have deviated slightly from the plan in terms of the hatches, due to my servo layout. Will post more once I've coaxed the turtle deck away from the fuselage.

Really love how the little Cygnet looks now, really coming into focus.

Gothiquity01/09/2020 21:52:28
49 forum posts
84 photos

Ok so after the planking comes the separation. , I'd left myself some guidelines for where to cut having previously applied clear tape to the fuselage and former inners to avoid things sticking where they shouldn't.

full.jpg

1 off .jpg

2 off .jpg

3 off .jpg

Ok so differing from Tim's design, which is more to do with my servo placement. Other than that fairly happy, though I made a couple of errors , but am hoping to fix those shortly.

Next step is to sort out the wing Jig so i can get the wings struts aligned and set along with the other brass and wire work.

Certainly getting there , its a challenge for me but I'm enjoying it.

happy landings

Goth

Tim Hooper01/09/2020 22:58:12
avatar
2911 forum posts
2412 photos

Goth,

You're making excellent progress! Keep the photos coming, OK?

Tim

Gothiquity03/09/2020 21:40:15
49 forum posts
84 photos

So only a little progress made today, made up the wing jig, and after checking my wing setup noticed incidence was out by a few mm , so had to do a little adjustment, both wings line up spot on now.

Must admit didn't realise just how important and useful that jig would be. Knocked together from spare balsa.

wing jig.jpg

sorry time for the dry fit so far shot

together.jpgLooking ok so far, very impressed. Wing struts only balanced in at this point. This is the kind of shot I see in other build logs that make me say I could never build that. Certainly spurred me on , really itching to see the Cygnet take to the skies, hope I can get it done before the bad weather hits.

Next decided to fit the brass work, originally i had fashioned the fittings from .016 inch thick sheet (K&S 8231) however i wasn't convinced it was up to the job so remade it with .032 thick sheet (K&S 8241)

took a bit of work getting it to shape , much sturdier and heavier, may need to swap it back out again.

upper brassjpg.jpg

That's the bottom of the upper wing with two brass fittings one for the flying wires, the other to get epoxied into the wing strut.

lower brass.jpg

the top side of the lower wing with a single brass fitting for the flying wires and wing strut.

Still loads to do, but I'm making progress at least.

Happy landings

Goth

Gothiquity05/09/2020 22:41:17
49 forum posts
84 photos

Hi all

So cracking on with the struts and brass-work, thought I'd share how I made my fittings, just so you know how I made them, no doubt loads of ways of accomplishing the same goal.

First using a copy of the plan I just cut out the relevant shapes and using a glue stick stuck the templates straight onto the K&S brass strip.

Once dried I snipped off the strips into the rough lengths, then using the handy guideline holes simply centre punched them to get a small dimple that I could then drill out with the right size bit.

Following that it was down to my ALDI power bench to grind off the excess brass, this was the hardest bit as the brass got flipping hot to the touch during this bit.

Shaping the brass to the paper template glue to the brass sheet. Holes already drilled.

brasswk.jpg

Once down to right size then just a very easy task of bending the brass to the right profile, again as shown on the plan, ( Hats off to Tim for providing such an excellent plan, takes a lot of guesswork out of the proceedings and eases the build along )

Spare copy of plan showing templates on plan, the brass sheet sanded to shape, then bent to profile and paper template removed.

brasswk2.jpg

Probably took me an hour to do all the brass work . Note the extra semi circular notes I filed into the flanges of the brass that gets epoxied into the strut, just did this to give the epoxy something to form around and make a better fit. Only time will tell if it works.

brasswk3.jpg

Couldn't put it off any longer ,time to commit, so epoxied the struts onto the brass work. Using the wing jig again firmly clamped in pace with strong elastic bands. I used pieces of clear tape to stop the epoxy sticking to the clamps.

strut 2.jpg

waiting for the epoxy to cure now , so will turn my attention to the motor mount, cowl, and faux Bristol Cherub.

Happy landings

Goth.

Gothiquity12/09/2020 22:41:12
49 forum posts
84 photos

Hi All

slow progress again.

Really wanted to make the wing struts look as good as possible, so following Tim's lead applied a liberal coat or three of B&Q's finest budget woodstain, also after a good sanding down added in the metal bracing plates present in the full size one.

Just in the process of adding a few coats of clear satin varnish to even out the finish.

here is the before shot with the basic strut and brasswork all glued/epoxied into place.

strut 3.jpg

And here is this the where I am up to shot, after woodstain and faux plates added in

strut 4.jpg

The plates are duplicated on each side just need to add some faux bolt heads to simulate full size. Really hoping the work hasn't cost me too much weight.

Next up turned my attention to the faux cherub , I tried a few methods to see what gave the best results. The lost string method using narrow 2mm strimmer cord, gave a nice enough effect , just didn't feel it provided enough depth for the model of engine. Next I tried carving blue foam, i don't have a mini lathe, and whilst the results were passable I'm really trying to get this looking as good as I can manage, so ended up using the method suggested by Tim, cutting out thin ply and balsa discs. simple and effective. only done the basics so far but think its looking ok.

cherub 1.jpg

That's all for now.

Happy landings

Goth.

Tim Hooper12/09/2020 22:49:51
avatar
2911 forum posts
2412 photos

Wonderful stuff! You've taken the concept far beyond my own limitations!

Tim

Gothiquity13/09/2020 21:23:25
49 forum posts
84 photos

Cheers for the kind words Tim, though I think my own limitations are fairly low at the moment.

Long way off matching your superb work yet.

Went flying this morning, however the wind had other ideas , managed a few circuits though nothing pretty, still managed to land in one piece and in the right field, always a good thing.

cracking on with the faux cherub i realised a little mistake, the Cygnet I'm trying to do is G-EBJI which does not have the cherub engine instead its a JAP J99 aero engine.

Quick bit of image searching had me tweak the original design

New cylinder head base coat grey on top off original cylinder now painted black.

jap1.jpg

Top side view showing cylinder head shape to roughly mimic the JAP J99

jap2.jpg

quick lick of aluminium paint to set it off, still a bit more work to do but looking ok

jap3.jpg

I'm using the cocktail stick to keep everything centred, as all the layers start out as discs so fairly easy to widen the hole made by the circle cutter to accept a cocktail stick. Just need to add in the exhaust, spark lead and cylinder head box.

This build really is pushing me to learn new things.

Happy landings

Goth

All Topics | Latest Posts

Please login to post a reply.

Latest Forum Posts
Support Our Partners
CML
Sussex Model Centre
electricwingman 2017
Slec
Sarik
Advertise With Us
Latest "For Sale" Ads
NEW POLL - has the pandemic altered your event safety perceptions?
Q: Has the covid pandemic deterred you from attending shows and events in 2021?

 No, I'll be attending just as many as I usually do
 No, but I'll choose my event with greater care
 Yes, I'll attend fewer events going forward
 Yes, I wont attend any where previously I have

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us

Magazine Locator

Want the latest issue of RCM&E? Use our magazine locator link to find your nearest stockist!

Find RCM&E!