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JB Aviation DH71 Tiger Moth


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Hi All,

This is a kit I have wanted for many years and when one came up on eBay I bought it. I asked the seller before purchase if there were any plans as I could see any in the photos provided and the seller assured me that none were provided just follow the instructions. Well, that was back in the summer and now that my Junkers F.13 is awaiting decals I just could not resist making a start.

On reading the instructions there were several references to "see drawing", so there should have been a drawing in the box. Now, this is going to be interesting to build. The tail feathers are all sheet so no problems there. I have spent most of the afternoon looking through the parts and trying to get my head around the build. Thankfully, included in the box was a 1974 copy of Aero Modeller with an article on the full size plus I have a few photos from the net.

I have an OS 52FS (70th-anniversary edition) waiting to be fitted

Only two full-size DH 71's were built, G-EBQU and G-EBRV, they were built in 1927 for high-speed research and a test-bed for the new Gypsy engine (QU) while RV had a cirrus engine. With just a wingspan of 22ft 6ins in standard form and a smaller 19ft speed wing.

QU took the 100km closed circuit record in it's class at 186mph faster than most of the RAF's contemporary fighters. It also made an attempt on the altitude record in it's class reaching over 19,000ft above which the pilot could not without oxygen although the aircraft was still climbing at over 1,000ft/min. In 1930 it was shipped to Australia where it crashed when the engine cut just after take off killing the pilot on September 17th.

RV was withdrawn from flying after a short racing career in 1928 and was stored in the rafters at the De Haviland works, this was destroyed when the works were bombed by a Junkers Ju88 on October 3rd 1940.

dh 71b.jpg

This is what it should end up like

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The box contents,

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Loads of CNC cut parts

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If anyone has built one of these I would be grateful for any advice. The fuselage build could be a bit tricky after the basics are done and at the moment I'm a bit lost on how the wings are to be built with the jig, perhaps it will come together as I progress.

That's all for now

Regards

Robert

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I saw one of these kits for sale, unstarted, at a swap meet years ago and quite fancied it but I was too slow and when I went back, it had gone! It's a model I've always fancied, too, so I'll be watching with interest.

My only crumb of advice is to search the on-line plans services like Aerofred and Outerzone for a sinilar plan. Even if it doesn't represent the one you're missing it'll be a guide.

Geoff

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Hi All,

Thank you for all of your replies. I have downloaded a plan which helps plus a fellow forum member is sending me some photos of the plan. So hopefully the build will be a lot easier with them as it feels as if I'm doing a jigsaw without the picture.

I have made some progress on the easy bits and getting sorted where some of the obvious parts fit but still a little puzzled in a couple of areas so far. I'm hoping the photos will help here.

I have glued the doublers to the fuselage sides and placed the servo tray and formers in position as well as mounting the engine and making the tail feathers.

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1 left side and 1 right side

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Nice new engine mounted

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Tail feathers and fuselage top all glued together,

So that's the easy bits done.

That's all for now

Regards

Robert

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Hi All,

Firstly, I must thank Martin for sending me photos of the missing drawings who's friend is building one at the moment what a coincidence as well some build photos.

I now have the "picture" for my jigsaw and so can proceed with confidence.

dh71 jb aviation drawing 1.jpg

Now it makes sense

jb aviation drawing 2.jpg

dh71 jb aviation drawing 3.jpg

So with confidence at high I made a start with the fuselage

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Servo tray and formers all of the parts are cnc cut and come away from their sheets with little effort and just trim off the tabs.

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Tail seat and former

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Second side on and all square

Building this took me back to when I built my JB/ATS Kite around 20 years ago.

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An advert from RCM&E 2002. I also fancied the Merlin as well as the DH 71 but I have never seen one up for sale.

I'll carry on with the fuselage tomorrow when the glue has set.

That's all for now

Regards

Robert

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The same friend who supplied the plans had a Merlin too - which flew very well and very regularly but sadly (IIRC) a non-extended 35 MHz transmitter aerial was its eventual undoing.

A little care may be needed when building the wings - the jig doesn't necessarily guarantee a true build although it certainly should in theory - we never found out why but his old one had a very significant twist in one panel when it emerged from his workshop! So much so that when I test flew it for him and started with significant aileron deflection already applied mechanically, I ran out of trim and had to put even more, but to give it it's due it has never detracted significantly from its flying characteristics even if it does look a little odd on the ground.

His latest one is as straight as a die...

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I built a foam/obeche wing version of the Dh 71 from a Pat French model purchased in 1985. It was my first low wing model and was a pleasure to fly. Powered by a plain bearing OS 40 but I don’t recall the wingspan. Same colour scheme of green and yellow but G-EBRV. Used caping strips on the top wing before covering with solartex to simulate the ribs.

Edited By Nick Somerville on 31/10/2020 17:10:18

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Hi All,

A little more progress today.

The mid to rear section of the fuselage was today's work area.

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Lower longerons in place and ply plate fitted to the left of the photo

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Once the lower longerons had dried it was time for the top triangle section.

The fuselage jig was not really required as the fuselage is self-jigging more for me to hold it in place I did check it after the glue had dried and straight and true.

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After a bit of sanding to the top edges, the top sheeting is then glued down.

Whilst the assembly is drying I had a dry fit of the front end, tomorrow's task.

That's all for now

Regards

Robert

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Hi All,

The front end took a bit of time to do this week, doing a bit then waiting for the glue to cure then do a bit more, and so on.

Fitting the battery floor, tank floor to the bulkhead went ok and dry fitting the formers and engine mount dry went well but got a bit messy gluing it all together with epoxy.

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After the epoxy had been left over night more epoxy was applied to the joints as per instructions and left to cure.

Then work started on building up the chin and fuel proofing before covering in.

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That's the chin done

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Next the hatch and greaseproof paper fitted to the joint to stop it from becoming a permanent part of the nose

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The lid fitted

Next, I'll plane/sand to profile before making the hood.

That's all for now

Regards

Robert

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Hi All,

The fuselage is progressing well with the hatch, cowl, and head fairing made and sanded to shape and the fin to tailplane glued together just about sums up this last week and she is starting to look the part.

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Engine fitted and adjustments made to the lower hatch

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Hatch upper sides dry fitted

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Cowl and hatch planed and sanded to profile

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Head fairing made and sanded to shape

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Fin to tailplane gluing.

This is coming along well with no problems encountered so far thanks for the drawings, I do feel that I would have made a mistake if I had not had them.

Next, to glue the tail to the fuselage and hinge the rudder and elevators

That's all for now

Regards

Robert

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Thank you, Martain, though I would not have thought there are many unbuilt kits still out there which is a pity because it is a nice build and a well thought out kit everything fits together as it should.

Although the wings might be a bit tricky from reading the instructions, I'll have to wait and see and rate it is coming together it won't be long.

Regards

Robert

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  • 2 weeks later...

Hi All,

I have made the wing jig and along with the first wing panel in the jig still a bit to do.

I had a slight misalignment with one of the jig corners not fitting right so I adjusted the joint. The jig is made in such a way that it is "virtually impossible to make it wrong" according to the instructions.

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The misaligned corner, at first I thought it may be for washout but when you flipped over the jig it would be wash in, not good.

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The jig is made from good quality 1/4 ply and is quite heavy

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All ready to start

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The main ply web spar is fitted first with the ribs pushed into the slots which are a very snug fit, a bit too tight really

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Just one casualty of the tight slots

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Spars and aileron fitted along with the trailing edge. The all the spars are hardwood with the front spars being doubled up 1/4 x 1/8th except for the last bay

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Getting the completed panel out of the jig was a little tricky due to the slots being tight which is good for assembly but no so good in trying to get the wing out without damage but it eased out a bit at a time.

I must say the jig is a good idea and works well especially as the wing tapers both top and bottom, I was a little apprehensive at first about using it but it seemed so quick to build no set squares, pins, or clamps.

I have flipped over the jig and fitted the ply spar web so I don't end up with two right wings!!!

That's all for now

Regards

Robert

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