New Products Flash Sale
Thread Tools
Old Jun 26, 2014, 04:01 PM
eye4wings is online now
Find More Posts by eye4wings
...design-build-fly-publish...
eye4wings's Avatar
Ware, herts. U.K.
Joined Sep 2008
3,607 Posts
Discussion
Robin Fowler designed DH83 Fox Moth

For all you DeHavilland fans this is another of my 'after-build' threads because the model is now into its second summer of flying and the design was published back at the tail end of 2013 in Quiet & Electric Flight International.

The plans are available under the Traplet Publications reference of MW3643 and a laser cut pack of parts is also available from the same source.

The model is at 1:4.8 scale spanning 76" and weighs 5 pounds 15 ounces giving a wing loading of only 9.25 ounces per square foot so it is well into 'floater' class! Because of this lightness I installed a 3-axis flight stabiliser unit from Orange which irons out all the turbulence she's met so far making her look rock steady in the air and a complete delight to fly.

Power is an XYH42-50 motor of 600kv swinging a 14" x 8" wooden prop and running off a 3S LiPo pack of 4,000mah which gives a good quarter of an hour in the air. ESC is a HobbyWing 60A with integral BEC although the maximum current draw with the stated prop is only 39A giving a 450W maximum draw.

The model takes as its inspiration G-ACEJ which was restored recently in the UK several photos of which are available on the internet.

So there's my introduction. Next post I'll get down to brass tacks!
Robin
eye4wings is online now Find More Posts by eye4wings
Reply With Quote
Sign up now
to remove ads between posts
Old Jun 26, 2014, 05:47 PM
Joe Pierson is offline
Find More Posts by Joe Pierson
Registered User
Joe Pierson's Avatar
USA, CA,
Joined May 2001
1,805 Posts
Hi Robin,
A very good introduction for sure A DeHavilland Builder from England what more can I say
It is always interesting to see and learn from other Builders. You will give us the inspiraation
we need.
I am looking forward to this build!
Joe
Joe Pierson is offline Find More Posts by Joe Pierson
Reply With Quote
Old Jun 27, 2014, 02:14 AM
eye4wings is online now
Find More Posts by eye4wings
...design-build-fly-publish...
eye4wings's Avatar
Ware, herts. U.K.
Joined Sep 2008
3,607 Posts
Thanks Joe.

On one occasion I got ribbed for turning up on the field with a new model that wasn't a DeHavilland design!

So far Leopard Moth, Dove, Heron, DH4, Albatross, Dragonfly, Fox Moth - not all of them published but all good flyers...

The Fox Moth was initially drawn up by me, at the drawing board the old-fashioned way but Traplets had decided that all their drawings had to be in CAD. I had tried to get my head around CorelDraw7 a couple of times - and failed so when Mark Winstanley showed interest in doing the drawing work I was more than glad to enlist his help. I sent him my drawings and we liaised month by month as they progressed.

The plan was that I would get a couple of sets of laser cut parts from his drawings one of which I would send to him and the other I would build into the prototype. That way I would find out exactly how the bits fitted together and pre-test for later purchasers.

Robin
eye4wings is online now Find More Posts by eye4wings
Reply With Quote
Old Jun 27, 2014, 02:55 AM
raipe is online now
Find More Posts by raipe
Registered User
raipe's Avatar
Finland
Joined Oct 2008
713 Posts
Subbed in

raipe
raipe is online now Find More Posts by raipe
Reply With Quote
Old Jun 27, 2014, 09:30 AM
Joe Pierson is offline
Find More Posts by Joe Pierson
Registered User
Joe Pierson's Avatar
USA, CA,
Joined May 2001
1,805 Posts
Good Morning to all!
Robin do the wings fold back along the fuselage? Laser cut parts are sure nice to work with!Also do they make a cowl for the DH Fox Moth
kit? I could not find one on the site. Does a list come with the kit, listing the sizes of the straight wood you have to buy?
Joe
Joe Pierson is offline Find More Posts by Joe Pierson
Last edited by Joe Pierson; Jun 27, 2014 at 09:57 AM. Reason: added text
Reply With Quote
Old Jun 27, 2014, 10:49 AM
eye4wings is online now
Find More Posts by eye4wings
...design-build-fly-publish...
eye4wings's Avatar
Ware, herts. U.K.
Joined Sep 2008
3,607 Posts
Joe,
There is no cowl because I built my prototype cowl up with all sorts of scraps reclaimed from the dust and bullets that lays in a thick layer all over my workshop.
I hate wasting material so all the offcuts of a possibly usable size get left around for such times as the cowls.
Similarly cabin windows and pilot's windscreen are from flat sheet... I think if I had to give a short punchy phrase to describe my work it would be 'scale for skinflints'!
I aim to make scale model building as accessible to the poor of the modelling fraternity as I can while providing an airframe any well-heeled scale enthusiast could go on to enhance with mitute features to his heart's delight.

There should be (I can't remember for certain) a wood list either on the plan or instructions (I think I remember doing it) for the Fox Moth - at least my editor Tony normally reminds me if such things are lacking.

The only item that may not be readily available over in the US is the Cyparis I habitually use for spars. This is called 'Port Orford Cedar' over there and I use it for its strength and flexibility whilst also being quite light. Over here it is a phone call to Blackburn Model Supplies away and available in up to 6 foot lengths (subject to extra postage!).

And yes, the wings do fold back for transport, pretty much as the full size except that I never did make up the extendable jury struts that Gary so kindly sent me details of taken from his Gypsy Moth. Instead I made up two lengths of 6mm dowel with wire loops at each end to slot into the wing fixings.
There are no wire or carbon tube wing joiners as the model is light and I used a cheap modeller's equivalent of the full size with structural rigging provided by 20lb. 'Pike wire' from the local fisherman's supply shop.

Robin
eye4wings is online now Find More Posts by eye4wings
Reply With Quote
Old Jun 28, 2014, 08:01 AM
bosley is offline
Find More Posts by bosley
Registered User
bosley's Avatar
United States, CA, Twentynine Palms
Joined Jun 2002
1,200 Posts
I look forward to following along on another trip. Not only do I enjoy your build style, but I have thus far enjoyed your chosen subjects as well.
bosley is offline Find More Posts by bosley
Reply With Quote
Old Jun 28, 2014, 09:45 AM
eye4wings is online now
Find More Posts by eye4wings
...design-build-fly-publish...
eye4wings's Avatar
Ware, herts. U.K.
Joined Sep 2008
3,607 Posts
Welcome bosley and all...

I don't remember too well why I started with the wings - probably because they are the easiest place to start - and I never start with the tail feathers because I prefer to have a fuselage there to fix them to at the earliest possible opportunity.
That may have something to do with the general mess in my workshop - and the consequent all too real possibility of parts like that getting lost or damaged!

First job is to cut the Cyparis spars to length and make up the fixings for where they join onto the fuselage. I mentioned before that there are no spar joiners at all on this model. I wanted to keep it really light so I was going to use structural rigging wires and attachment hard points just like the real thing in essence - but simpler design to suit model scale.

One of the things that is particular to the use of Cyparis (POC) is that I was told that it doesn't like superglue. So, being a bit rebellious by nature, I decided to try it anyway for its speed. The result you'll see later - it discolours to a nasty dark brown mess - but it did seem to stick well enough to hold it while I got the rest of the structure on to hold it with wood glue, so I didn't redo it. There was in any case a good mechanical joint by reason of passing the tails through holes in the spars - which is at right-angles to the stress.
Just a bit of insurance - belt and braces!

Robin
eye4wings is online now Find More Posts by eye4wings
Reply With Quote
Old Jun 29, 2014, 02:17 PM
eye4wings is online now
Find More Posts by eye4wings
...design-build-fly-publish...
eye4wings's Avatar
Ware, herts. U.K.
Joined Sep 2008
3,607 Posts
Hmm, that was interesting - the system lost all my uploaded photos, se here's my post re-done.
I wonder what happened to the original ones? Room 101? Limbo?

Robin
eye4wings is online now Find More Posts by eye4wings
Last edited by eye4wings; Jun 29, 2014 at 02:31 PM.
Reply With Quote
Old Jun 29, 2014, 02:27 PM
eye4wings is online now
Find More Posts by eye4wings
...design-build-fly-publish...
eye4wings's Avatar
Ware, herts. U.K.
Joined Sep 2008
3,607 Posts
Hello again!
Any of you who had a close look at the laser cut sheets may well have noticed that the ribs look as if the spars are flush to the bottom of the wing. Not so!
Here's the story...

For my Dragonfly build I had a wing kit cut by someone who chose to thin down even further the design I sent him. This had the spars fed through two slots in each wing - and there was so little wood left that I had difficulty feeding the spars in without breaking them. I did manage to do it but several spars needed gluing, one or two more than once.
In the end I rebuilt the wing by stripping everything off the spars for re-use and laid strips of 2.3mm medium balsa, laid the spars on them and adding the top sections of the ribs just like you see on those laser cut sheets. It worked well so I decided I would do the same on the Fox Moth right from the start.

The strips, being the bottom parts of the ribs (rather like cap strips), butt up to the trailing edge, then I cut slots in the trailing edge to take the main ribs which serve as jigs to hold the spars in place. That way the joint between t.e. and the tapering trailing edge of the ribs has some strength. At the front end the strips offer slots for the Cyparis leading edge to slip into after which the little intermediate riblets fit in like clockwork. I just love the way these 30's wing structures look and go together.

So here are a few more shots...

Robin
eye4wings is online now Find More Posts by eye4wings
Reply With Quote
Old Jun 29, 2014, 06:13 PM
baldguy is offline
Find More Posts by baldguy
I eat glue
Canada, NS, Yarmouth
Joined Jul 2006
3,719 Posts
Looking good! I'm such a bad, bad boy for not working on your other design! Haven't done any building ina lonnnnnnnnnnnnnnnnnnnnnnnnnnnnnnnng time.

I'm thinking I need a larger Robing design to get me inspired again, something simpler. Oh say, a Zenair!
baldguy is offline Find More Posts by baldguy
Reply With Quote
Old Jun 30, 2014, 03:35 AM
eye4wings is online now
Find More Posts by eye4wings
...design-build-fly-publish...
eye4wings's Avatar
Ware, herts. U.K.
Joined Sep 2008
3,607 Posts
Hey Craig!
I have just replied to a PM on the subject of the Zenair... so 'watch this space' as they say. There may be an 'after build' on that one coming up too....

It would certainly be a simpler build than this one - though it does have its' 'busy points' like the cabane and the mechanical mixing - but that is optional - it was only rendered desirable (even essential) by my entry level radio gear!
eye4wings is online now Find More Posts by eye4wings
Reply With Quote
Old Jun 30, 2014, 07:26 AM
destrat is offline
Find More Posts by destrat
Registered User
destrat's Avatar
Joined Apr 2009
125 Posts
Robin:

Good to see you are at it again with the Fox Moth keeping all of us DeHavilland fans happy. Nice work, will be interested in following this thread.
My Dragonfly is ready for her second maiden flight following the horrible crash last summer at the "WATTS Over Owatonna" all electric fly-in. I figure I would save it for the meet.
I came to the conclusion that the radio battery pack lead got pinched as all the batteries are in the same area. When installing the motor batteries in their box, inadvertantly pinched the radio battery lead which then broke in flight due to possible shifting, was the negative lead, as they say "oh well".
Isn't it amazing how much money we can put into these models when in reality success is determined by a little positive/negative connector.

Keep up the good work....

Dan
destrat is offline Find More Posts by destrat
Reply With Quote
Old Jun 30, 2014, 07:51 AM
eye4wings is online now
Find More Posts by eye4wings
...design-build-fly-publish...
eye4wings's Avatar
Ware, herts. U.K.
Joined Sep 2008
3,607 Posts
Hi Dan,
Good to have you along!

At least you have a good idea what cause your Dragonfly to crash - I still have nothing but conjecture to explain mine.

(For those who are wondering what all this is about the discussion is on my DH90 Dragonfly thread).

Both Dragonfly and Fox Moth share the van with my Stirling at present.
A few posts ago Joe asked about the folding wings and I did a search of the folder to see if I had a photo to post showing the wings folded. Came up blank!...
and mentioning the Stirling just now jogged my memory.

Robin
eye4wings is online now Find More Posts by eye4wings
Reply With Quote
Old Jun 30, 2014, 08:43 AM
destrat is offline
Find More Posts by destrat
Registered User
destrat's Avatar
Joined Apr 2009
125 Posts
Robin:

Boy, that is a van full. I have to pack all my stuff into the back of my pick-up truck just right too, or only take one plane. There is something to be said about building small, but then again.

Dan
destrat is offline Find More Posts by destrat
Reply With Quote


Thread Tools

Similar Threads
Category Thread Thread Starter Forum Replies Last Post
Discussion de Havilland DH.83 Fox Moth TedD60 Scale Drawings and Three Views 9 Nov 24, 2014 01:57 AM
Build Log BBCC5- FF Fox Moth to R/C Zephyr41 Balsa Builders 13 Aug 24, 2014 05:00 AM
Build Log Robin Fowler`s P40 Kittyhawk version 2.0 marek84 Scale Kit/Scratch Built 6 Dec 17, 2013 04:43 PM
Build Log Robin Fowler`s P40 Kittyhawk marek84 Scale ARF/RTF 18 Jun 16, 2013 12:28 PM
Discussion IOM ONE DESIGN Round Robin Sailor_Guy Sailboats 63 Nov 26, 2012 05:10 AM