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

Hawker Cygnet

build blog and chat

All Topics | Latest Posts

Search for:  in Thread Title in  
r6dan27/02/2011 18:23:21
avatar
1107 forum posts
46 photos
Another fantastic looking plane You got there Tim
Danny Fenton27/02/2011 18:35:56
avatar
9068 forum posts
3928 photos
Hi Tim, looks fabulous, sounds like you need to play with some lith plate
 
Cheers
Danny
Tim Hooper27/02/2011 19:19:05
avatar
2853 forum posts
2363 photos
Dan(s),
 
Thanks lads! It's starting to come together at last. The balsa work is essentially finished, so now it's the hardward side of the project.
 
Danny, I've never used litho plate, but I heard that it used to be available from printworks. Do they still use such material at all?
 
tim
Danny Fenton27/02/2011 19:43:37
avatar
9068 forum posts
3928 photos
Hi Tim, yes I believe they do. I got my last batch from E-Bay. Probably not a bad idea to stock pile a little if you can. Wish I could send you some but I haven't much. If you rub normal soap on one side and heat with a blow lamp on the other until the soap goes black, then it is really malleable and will take compound curves beautifully. Once it work hardens again then more soap and more heat. I have seen some beautiful work done by the likes of Ian Redshaw.
Dont cut it with scissors but score it and fold back and force gently it snaps beautifully with a lovely clean edge that even you would approve of
 
Cheers
Danny
 
 
Tim Hooper28/02/2011 07:53:40
avatar
2853 forum posts
2363 photos
Cheers Danny!
 
I'll have a search on eBay later on.
 
tim
Danny Fenton28/02/2011 11:00:23
avatar
9068 forum posts
3928 photos
Hey Tim, if you draw a blank, I will send you a sheet. My stock is pretty low myself but it would be perfect for this model and I know its going to a good cause.
 
Cheers
Danny
Tim Hooper28/02/2011 12:30:39
avatar
2853 forum posts
2363 photos
Thanks Danny!
 
I think I've got it sorted.......
 
tim
Klippy28/02/2011 14:20:20
avatar
746 forum posts
13 photos
Tim, what about the thick foil dishes that the stores use for putting cakes and pies on?
Tim Hooper28/02/2011 22:25:01
avatar
2853 forum posts
2363 photos
Posted by Tony Prince on 28/02/2011 14:20:20:
Tim, what about the thick foil dishes that the stores use for putting cakes and pies on?
 
 
But what about all those calories?
 
Thanks for the suggestion, Tony, but I thinks there's some pukka lithoplate on its way (as opposed to Pukka Pies, that is.....)
 
 
Just to pass the time this evening, I knifed out some little discs from 1/16 balsa, and some slightly larger ones form 1/32 ply......
 

...and then threaded them onto a BBQ skewer!

With the cylinder barrels made, I cobbled up some cylinder heads from some little bits of scrap.

And there you have it - a 100% accurate facsimile of the little-known Generic Twin engine! Just needs a little more detailing - inlet, exhausts, plug etc.
 
tim
Klippy01/03/2011 04:56:41
avatar
746 forum posts
13 photos
Lovely work as usual Tim
Tim Hooper02/03/2011 18:36:57
avatar
2853 forum posts
2363 photos
Thanks Tony!
 
I did a little more work on the dummy engine last night.
 
Inlet/exhausts, pushrods, plugleads....


.....and then cutout an appropriately sized hole in the side of the cowl for it to hang out of!

 
 
Danny Fenton02/03/2011 19:04:28
avatar
9068 forum posts
3928 photos
looks really great Tim, how did you bend the brass tubing so neatly?
 
D
Stephen Jones02/03/2011 19:12:34
avatar
2632 forum posts
1500 photos
Yes very nice work there
 
Will there be a how to make the dummy engine details on the plan
 

Edited By Stephen Jones on 02/03/2011 19:14:26

Pete B - Moderator02/03/2011 19:40:38
avatar
Moderator
7544 forum posts
729 photos
Hi Tim,
 
Another excellent Hooper thread, as always! I've just been reading Neville Duke's book, 'Test Pilot', and it it he refers to the Hawker Cygnet in the Dunsfold museum. I quote -
 
" It has a little 36HP Bristol Cherub engine, a top speed of 75 miles per hour, drooping ailerons which can be wound down as flaps. This type of full span, narrow chord aileron may be seen on very fast aircraft again shortly." (Written in 1953)
 
I must say I'd never considered flaps on a biplane - could you see any advantage at model size?
 
Pete
 
Tim Hooper02/03/2011 20:20:46
avatar
2853 forum posts
2363 photos
Hi Danny!
 
Du-Bro market a miniature tube bender - meant for dealing with brass fuel tubing. Netty bought one from Pegasus Models in Norwich a couple of weeks ago (for bending silver tubing), so I thought I'd better give it a test flight!
 
Stephen,
 
I'll add what details I can, particularly the dimensions of the discs. Other than that I sort of made it up as I went along....
 
Pete, Thanks for the reference! I've no idea if the Ciggies ailerons could be used as flaps, but to describe them a 'narrow chord' really is a mistake; the upper ones are around 35% of the total wing chord!
 
Mind you, flaps on full-sized biplanes certainly aren't unknown - the Gloster Gladiator springs to mind, so I'm sure there are more out there - but at model size?  I really don't know if they'd be worth the effort, particularly on a lightly-loaded model such as this.
 
tim
 
tim

Edited By Tim Hooper on 02/03/2011 20:22:32

Tim Hooper05/03/2011 10:02:07
avatar
2853 forum posts
2363 photos
Now, I've built quite a few multi-winged models before and one of the trickier bits is keeping the wing panels in some sort of alignment whilst all the all interplane struttery is constructed.
 
So, can you guess what this is yet?
 
With the incidences at the wing roots all sorted, it's an easy matter to cobble up a balsa balsa frame in-situ, that lies along the underside of a couple of handy ribs. It's held in place by a couple of elastic bands. Oh yes, I've painted it a pretty colour just so it shows on the photographs too!


The idea is that we can then slide this gauge outboard to nearer the tips. The only slight niggle is that the dihedral on the lower panel causes the upper and lower panels to converge. This easily sorted by adding another strip of balsa under the lower panel to compensate.

So there we are. The upper and lower wings are now aligned both incidence and dihedral, all ready to have the interplane struts added. Easy, peasy - and took all of 5 minutes!
 
 
Now at the other end of the workshop, I enlisted our resident panel-beater to make a start on the lithoplate cowl. Netty is using a round-ended mallet and a sand bag to make the initial curves in the metal sheeting.

Then she moves on to a hide mallet and a metal 'stake' to smooth out the cowl as she goes along.

This is quite a time-consuming operation. It would be easier if she could shape the lithoplate around the balsa cowl itself, but it's just too fragile for that. As an added complication, the sheeting has to be annealed with a gas torch fairly frequently, as it work-hardens as it's being shaped.

 

Edited By Tim Hooper on 05/03/2011 10:03:23

Edited By Tim Hooper on 05/03/2011 10:04:29

Klippy06/03/2011 08:03:34
avatar
746 forum posts
13 photos
Hmm, this won't compromise the 'builder of the model' rule will it?
Tim Hooper13/03/2011 09:25:46
avatar
2853 forum posts
2363 photos
Posted by Tony Prince on 06/03/2011 08:03:34:
Hmm, this won't compromise the 'builder of the model' rule will it?
 
 
Very probably!
 
Anyway, we're having problems getting that thin plate to form around the compound curves of the cowl without buckling too much. Even Netty's night class tutor was scratching his sage pate........
 
Anyway, just to put the matter to one side for a while, I've returned to the relative comfort zone of the interplane struts!
 
Each strut will be made of three layers of 1/16 ply, with the middle lamination cut away to make room for the brass end-fittings. Here's one of the outer laminations with the brass fittings alongside.

The lower fittings are bolted to the wing....

....as are the bifurcated upper ones.

The model is then assembled (using our wing jig), the outer ply strut is epoxied to the fittings. Has to be right, right?

tim
 
Danny Fenton13/03/2011 09:36:38
avatar
9068 forum posts
3928 photos
Hi Tim keep at it, just to prove it can be done here is the "Lord of lith's" work on a Hurricane fairing......
 

Ian Redshaw's work, he is very good with the stuff...........
 
Cheers
Danny
 
Klippy13/03/2011 12:05:37
avatar
746 forum posts
13 photos
Jaw drops onto the keyboard! Awesome!

All Topics | Latest Posts

Please login to post a reply.

Magazine Locator

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

Find RCM&E! 

Latest Forum Posts
Support Our Partners
Pepe Aircraft
CML
Revoc
electricwingman 2017
Motion RC
Slec
Wings & Wheels 2019
Gliders Distribution
Sarik
Advertise With Us
Latest "For Sale" Ads
Does your club have a safety officer?
Q: Does your club have a safety officer, or is the emphasis on individual members to each be their own safety officer?

 Yes we have a SO
 No, it's down to everyone

Latest Reviews
Digital Back Issues

RCM&E Digital Back Issues

Contact us

Contact us