Tiger Moth to Fox Moth

[andy wood]

@John Aeroyou are a true gentleman

 

[Paul J]

I still have an Aeroclub one in my builds but needs much repair!!  Lovely little kit John Aero! Any  chance of a come back....

[John Aero]

It's often difficult to sort out truth from myth sometimes. In aviation there are lots of quotes such as "the Fox Moth used Tiger Moth wings" yet every scale type three view drawing including DH material shows slightly different wings, so the obvious answer must be "of course they were modified to suit".  This is often true but in the case of the Fox Moth the mods to the wings were minor and the major difference was in the centre section and this has just not been drawn correctly.  

 

Finding a source for the right answer is often difficult, it's time consuming and occasionally expensive and at the end there's only a small number of folk who are interested.  It always starts with "if that's the stated case then why..."

 

But it's fun..

 

John

[John Aero]

This is the Fox Moth layout I've worked out so far and as far as I know this is the first time this explanation has appeared in print anywhere. Again my thanks to Stan Smith the New Zealand DH restorer. 

 

The vertical darker Blue struts are the forwards cabane struts which are vertical and parallel to each other in front view.

 

The vertical Red struts are the real rear cabane struts which are at an upwards diverging angle and not parallel like the front ones.  in side view these struts both slope forwards 3" and are parallel to one another.

 

The pale Blue vertical lines are the incorrect rear cabane struts as drawn in plans.  The incorrect centre section shape is represented in White.

 

The Yellow lines show the actual angles of the Tiger Moth wing roots.

 

The sloping Red lines show the angle of the fairing of the tank to the wing roots. Note the rear lines have a shallower angle (as the tank top curves down, but note the rear lines are longer as the centre section widens to the rear.

this is because the rear c/s spar is longer that the front c/s spar. The pale Blue triangular  areas represent the widening of the centre section to the rear.

 

The top wing spar fittings are standard Tiger Moth  and attach to the c/s spars.

 

The lower wing rear spar metal fittings of the Tiger Moth wings are replaced by longer fittings and attach to the lower fuselage similar to the Tiger Moth.

 

On the Fox Moth above, fairings have been added to the lower wing but I think these fairings are not always fitted as standard.

 

John

 

 

 

 

 

[Dave Fleming]

OK, looks do-able, especially in 1/72

[andy wood]

Wowsers John. You are the gift that just keeps on giving! I think this will be very helpful. https://www.youtube.com/watch?v=0W1-y_6Qnfk.  Not only does it  have good close up footage, including cockpit and engine, take a look  from about 9 min 30 until 11.00. Very good overhead shots of both Tiger Moth and Fox Moth upper surfaces, showing centre sections to good effect

Edited September 27, 2016 by andy wood

[TonyTiger66]

Thank you John that is superb information. 

 

You have turned this into a pretty special thread  

 

I think we Fox Moth people are very happy right now.

 

It will be good to see your build when it gets started Andy, with this info it could be the first really accurate model Fox Moth in the 21st century; possibly far longer.

 

All best regards

TonyT

[John Aero]

That's a brilliant little video and so much the NZ light aviation scene. The field is typical of the small suburban airfields  and I always try get up to Rangiora strip when I'm in NZ, visiting my son. A request to look around the hangars and take photos is always met with a "no problem". The last time the reply was "course, but would you help me rig my Bleriot first".

 

The video confirmed everything I had worked out. That particular Fox was a Canadian built one as it has the lift up cowls and a proper rear cabin seat. The British Foxes have a thing like a leather deck chair. I understand that the lower fuselage also has a taper which also takes up some of the wing sweep changes.

 

The guy flying the Fox was Stan Smith.

 

John

[John Aero]

To show how slim the rear fuselage is. Yes that is Mike McEvoy by the Stb wing..

 

John

 

[andy wood]

20 hours ago, TonyTiger66 said:

 

It will be good to see your build when it gets started Andy, with this info it could be the first really accurate model Fox Moth in the 21st century; possibly far longer.

 

All best regards

TonyT

Bloody hell Tony, don't set me up for a fail! John, it's all down to your drawings now. If I cock it up, i'll blame you!

 

I've just ordered some bit and bobs for the build, but does anyone know where I can get the HGW 1/32 British rib tapes? They are not listed on their website, but I know they exists because there are plenty of pictures of them on the internet.

 

As soon as I finish my Meteor I will make a start

[Dave Fleming]

2 hours ago, John Aero said:

To show how slim the rear fuselage is. Yes that is Mike McEvoy by the Stb wing..

 

John

 

 

 

Very obvious change in section just aft of the cockpit

[Barneydhc82]

I have the book, The DeHavilland Story by Fred Hotson in front of me and on page 93 is a photo of ZK-APT, which was shipped from DHC to New Zealand after WW2

 

Barney

[TonyTiger66]

8 hours ago, andy wood said:

Bloody hell Tony, don't set me up for a fail! John, it's all down to your drawings now. If I cock it up, i'll blame you!

 

I've just ordered some bit and bobs for the build, but does anyone know where I can get the HGW 1/32 British rib tapes? They are not listed on their website, but I know they exists because there are plenty of pictures of them on the internet.

 

As soon as I finish my Meteor I will make a start

 

 

My apologies! I didn't mean for it to come out quite like that Andy  

 

ATB

TonyT

[TonyTiger66]

On 25/09/2016 at 5:36 PM, JWM said:

Tony, I had once also the idea of doing Fox out of Tiger (in 1/72 from AZ kit or rather from scratch) - here is my attempt,  

I am not 100% satisfied, but it was a nice play... I based mostly on drawings from Spanish book on British, Czech and Polish airplanes in Spanish Civil War ("Aviones en la guerra civil ..." - we talk about this biik on group buil forum). This was my last build of a biplane without EZ cable...

 

Cheers

Jerzy-Wojtek

Thanks Jerzy-Wojtek,

It's a nice model  

I must ask Mrs. Tiger to bring the book to me.

 

I don't think I have the skills for a conversion like that. John Aero's kit would have been ideal, so I'll search for a secondhand one or the Resin kit (as it seems they are very similar  !).

 

I'm going to wait for a good picture of the floats though, as it seems plans can't  be trusted too well 

 

I have found out there was a Kiwi Resins kit too, but again it is long oop.

 

A Leopard Moth would also be rather nice......  

 

All best regards

TonyT

[andy wood]

6 hours ago, TonyTiger66 said:

 

 

My apologies! I didn't mean for it to come out quite like that Andy  

 

ATB

TonyT

Giggle!

[John Aero]

I won't be able to post for a few days so The Fox will be quiet for a bit. I've had some more info on the Fox but I have reason to believe it might be in error, so I need to check it out 

 

Cheers

 

John

[andy wood]

Big thanks for what you have provided us with so far 

[John Aero]

I've got a bit more time to play than I thought so here's something to ponder.  I use a number of photo interpretation techniques and my favourite and amazingly useful but time consuming is measurement analysis by ratio against a known dimension.

It works only on certain photos and there can be errors depending on centre points and within certain angles and distances and you need more than one photo for any real comparative use.

 

This is an almost perfect example, blown up from a distant shot.  An electronic tracing of the Granger plans, (which are remarkably similar to the 1943 Aeromodeller plans when compared on a light board) fits over this photo like a glove.

 

All John Adams photographs.

 

The next two are no use for the above but they have a use. Both aircraft are in a similar attitude and size and can be used for lines of projection as can the earlier rear view.  I'm struggling with the apparent use of a pure Moth 60G rear fuselage. The empennage is DH 60G.

One information says the rear end was pure DH 60G Gipsy Moth from the pilots bulkhead, (forget the head rest fairing it's bolt-on) and the other says made up of largely 60G components.

 

Now if the former is true then the width of the fuselage should be +/-  24" at the pilots bulkhead/seat back (Moth fuselage width)..  The cabin dimensions for the Fox which I have are 2' 9" wide which I think should give a close approximation of 36" total fuselage width at it's widest point over the door sills (forget the bulged doors). 

 

If we project lines along the fuselage lower edges on say the Granger Fox Moth plan it shows that the fuselage max width is close to 36" but the fuselage width at the rear of the cockpit is near 27" and not 24"

To make the 24" dimension fit then the fuselage should "tadpole". Look at the  rear view photo, it clearly doesn't. Now look at the two comparative pictures below. The top is a Fox and the bottom a Tiger which has a similar width fuselage to the Gipsy Moth at the bottom..  It's my opinion that the first statement is a simplification of the second. and that the Fox rear fuselage is made up of modified 60G fuselage side panels but with a new wider top turtle decking and bottom sections.

 

 

 

John

[andy wood]

Thanks very much John. In earlier posts you mention about the differences in cowls. I have looked, and looked, at both period and current photos and I cannot see any differences. Can you expand on that?

[John Aero]

Andy

 

Very quick as it's late, The British cowl is made up of 5 pieces, nose cowl. a bottom tray, a top cowl and two cheek pieces which hinge at the sides to the top cowl. (on ZK-AGM the side hinge is along the top of the nose paint trim) The Canadian cowl (fitted to the NZ Fox in the video) has three pieces, two cheek pieces which hinge on the top centre line and the front part splits vertically round the prop to the bottom and then a bottom tray.  It is supported on the inside by a light tube frame. The give away on these aircraft is they usually have the bigger aft pointed cabin doors.  The Canadian Tiger Moth C.3 has a similar cowl,

 

Regards

 

John

[andy wood]

Now you have pointed it out,it was so obvious! Boy do I feel a div for asking!

[Jessica]

Could it be that the gypsy moth fuselage frame was used and aerodynamic fairings were added to the outside which broadens the cockpit to the measured width?

[Barneydhc82]

I'mreading the DeHavilland Canada Story and the author states that the post war Fox Moths used Tiger Moth wings and tailplanes along with the Gypsy Major 1C engine but no mention of the fuselage source..  The first flight of the new production Fox was 5 December 1045 at Downsview, Ontario. ( CF-BFI-X).  A total of 53 aircraft were built until the line closed in 1948

 

Barney

[JWM]

Jessica - please note, that the Fox fuselage is not only wider but also longer then the Tiger's one - have a look at the photos above - what is a distance between bottom wings and end of engine. Similar the distance between wings and tail is longer in case of Fox, thou it is not so easily noticable

Cheers

Jerzy-Wojtek

[John Aero]

I've just got back from Malta, so I can pick up this thread again.

 

Re Jessica's comment. The wooden Gipsy Moth fuselage is basically a spacer and longeron edged one piece plywood box from engine bearers to tailpost. On top of this are plywood turtle decks. There are no bolt together sections so they couldn't just use the rear fuselage off a Moth to bolt onto a new wider front fuselage.

 

How I see it, is that the basic rear fuselage component parts for the sides of the Moth, up to a point around the back of the rear cockpit, were assembled with new wider traversals, ply bottom and topdeck. This new wider 'Moth' rear end was then joined to the all new, wider cabin of the Fox Moth with the longeron joins, strengthened by fishplates.  The plywood cabin top and cockpit area were faired into the rear turtle deck making it a new one piece fuselage.

 

I'm drawing up the Tiger wings from the Warring dimensioned drawings which will then be set up at the correct span and sweep back angle and the centre sections can be drawn into place. The fuselage drawings which I am quite happy with will then be overlaid and as it's an electric drawing any adjustments can be made as more info comes to light.

 

John