David Ovenden

Hi Martin, Yes I'm watching with interest. I should post more often but I suspect, like others, we dip in and watch without posting a comment. A lovely project, beautifully crafted. Great work!

I had a go with photo shop and managed to come up with this image. Its not completely correct (spacing and horn got cut off a bit!) but I think it will have to do for a sport scale model. I printed it onto decal paper so it should be nice and thin and not show up too much on the model. I also know that the "crown" is not the correct version. In the photo it is a "rare" 1936 Edward VIII crown however, maybe they repainted the logo later once he didn't become king? That's my story anyway!

Great work Danny. If only I had your painting skills. When at secondary school my Art teacher came to very happy arrangement with me. If I did a couple of things each half term I could do homework in the other lessons. He didn't have to suffer so much of my less than great art; I got some other work done; so both of us were happy. On the other hand; I could never get enough of Wooodwork, Metalwork and Technical Drawing classes and was always good at those subjects. Horses for courses.

I've now cut out another set of letters and replaced the "non-stick" ones. I need to work on the small lettering and the "Royal Air Mail" logo next. I'm thinking of trying to paint it on clear film. We shall see how that works out!!

I managed to get some lettering cut out and applied today. Unfortunately the white solartrim seems to have lost its adhesive powers so it looks like I will have to re-do the fuselage lettering.

The receiver and servos are all fitted and the linkages are set up. I have now weighed the completed model (well cockpit glazing and registration lettering still to add -but only a few grams there)) and it comes in at 4.77kg (10.5lbs) complete with lipo pack. It balances spot on the CG marked on the plan so there shouldn't be any extra weight to add (I hope) My target was 5kg (11lbs) so I'm happy to have come in just below that. I added some sprung oleo legs that added a bit; but used film rather than Tex covering so lost some potential weight there. I calculate wing area of the model at 8.9sq ft so that's a wing loading of 19 oz / sq ft which is not too bad I reckon. Power from the 2 motors is 1200w max so the power to weight ratio is 114watts per pound (250w per kg) which should prove be sufficient to give good performance for this type of plane (1930s biplane airliner). Currently I am planning to use a 7000mah 5s pack to run both motors. These are from BangGood and I have my doubts that they really are 35C batteries (as claimed) They only weigh 660gms, which is great to keep the weight down and they do come with 2 output leads (one XT60 and the other Deans)which is useful for a twin ESC setup. (See photo below). I do also have a Zippy 8000mah 5s pack that will fit in but is considerably heavier at 900gms. However, this could be moved further back in the fuselage so no extra (compensating) weight would be needed but it would still add a porky 240g to the AOW but give longer flight times. We shall have to wait and see how it all works out after the first test flights. Next step is to get on with the detailing (pilots and markings)

Getting towards the final stages of the build now. I still have to glaze the cockpit windows and fit the motors and props. I needed to move the motors a little further forward to give the correct clearance between the propellers and the cowl. I am waiting for the screws to arrive. In the meantime the model balances on the plan-marked CG so that is positive.

Really struggled getting the BangGood film to go round all the double curvature of the nose. I'm not really happy with the result and may well strip and use glass-cloth and paint later. But I'm going to leave it as is until after the test flight, not least because I have no paint the right colour to match the film. I've still got the cockpit glazing to do, but pilots can wait. As the whole nose comes off it will be easy to add them later. I don't have any 1/12th scale 30's US commercial pilots so I will need to make some from foam I guess.

Nearly there with the fuselage now. It's mostly covered with just the nose/cockpit area to do. It feels amazingly light without radio, centre section/motors etc. The rudder and elevator servos are in the tail accessed by a panel either side under the tailplane. I can just get in to make adjustments and it is possible to remove the servos if needed. I hope I don't have to though. Not much space to spare inside!

Could do with some good ideas. I want to create a decal/ sticker/ logo. How to create the Royal Air Mail logo to put onto a red film-covered fuselage? I don't want to try painting by hand! The black and white photo just shows the logo on the actual plane being modelled. The other 2 images give a bit more detail of what is required.

Finally managed to get somewhere with the folding wing struts and rigging. The system is all installed now and it works as I imagined. I spend half a day fabricating rigging brackets. Rigging wires were made and installed and the wing panels remove as a pair now (left side & right side) The wings have carbon tubes so are structually strong enough for the rigging to be "additional" rather than "essential". Each outboard panel is secured by a single 4mm countersunk bolt on the main spar. In addition the flying wires connect via 2 removable links to the engine nacelles. The landing wire connect to the underside of the top outer panels so can stay connected when the panels are removed and folded. So removal of all 4 outboard panels only means removing 4 screws and unsnapping 4 kwick-links.

I think that perhaps perspective makes the model look a little bigger than it actually is. However, at 82" span (top wing) it's not small. Hence the desire to make the outer wing panels remove and fold down to aid storage and transport. The original had one-piece wings. The lower wing was complete with u/c and the engine nacelles with the upper wing mounts and nacelle-to-fuselage struts still permanently attached. The plan shows that there would be 24 screws or bolts to undo each time you wanted to remove it. Not convenient at all. My method means there is one retaining screw for each outer panel (so 4 in total) plus 2 kwik-links each side to remove the lower rigging wires.

In case it is useful, I believe the exhaust thread on the Saito 82 is fine pitch metric 12mm x 1mm pitch. I was able to buy tap and die in this pitch for a reasonable price. If you have a lathe you may be able to cut external threads without a die I imagine.

Not going very fast on this at the moment as I'm still finishing off the Condor. However, I did manage to use the U/C side view photos to plot the pivot points on the mechanism. I measured these and it comes out pretty close to the drawings I have of the Robart units, so it seems that its about correct.

Thanks GG, Somehow the finishing off stages seem to take much longer to sort out than the building the main airframe structure itself. Still I think its getting there now. Only got the LiPo battery bay to build into the nose and to sort out the cabin window framework, then I can cover the fuselage.

Today I found some ball links from an old helicopter and made up some right angle brackets to fit them to the wing. I fabricated a "trial" single wing strut which fitted fine and allowed the strut to fold down as required. As this is a "sport scale" model I haven't worried too much about the strut wing joint. I have tried making up a flexible "boot" from heat shrink tubing that slides down to cover the strut mounts and will flex to allow for the struts to fold for storage. OIt's not very elegant but it will make it a practical model to store, transport and assemble easily at the field. I hope!

I had rather a wasted day today. I started to build the interplane (wing struts) and had decided that I wanted to make them hinged so the wing "pair" could fold with rigging attached to make transport and storage easier. On paper it all looked good. However, having made up 8 hinged mounting points it dawned that it wouldn't be that easy to make it work as the camber of the wing section meant the hinges would not be parallel with each other and so the struts would fold without stressing and breaking. Next I attempted to get the mounting points level, but that looked awful. So, unless I come up with a better plan (ball joints???) it looks like it will be fixed wing struts. It's how I learn - getting things "wrong" first time! No photos as nothing to see.

Been working on servo instalation. The good news is that with the lipo up front there is no problem with CG. In fact, it's a bit nose heavy so the rudder and elevator servos have gone in the tail end. I had to make a custom servo mount unit to fit in the JR NX3421 servos. I wasted much of the day searching for the receiver to test the linkages/ set up. I had a 6ch rx sorted and bound to the Tx but it's gone missing. I've searched everywhere but can't find it. It was on the bench but I'm starting to think I must have thrown it out in the rubbish when I cleared up last!! In the end I had to use another rx.

Little bit more done today around blood tests and visit to doctor. I have also been working on ideas for the Bobcat project, so got less building done.

Of course, I could always go for the fixed u/c option. I've found this photo! Would need small props though as there is little ground clearance.

Thanks Max. Nice video and that gives me another avenue to pursue. I'm sure that I will need to make a nacelle "mock-up" (as you did) to test the retract operation before I start the build.

Thanks Danny. I've found some suitable?? forked oleos from HK. I've ordered those and will have a look at possible systems when I have them to hand. If that doesn't seem to work out I'll take up your offer to contact Brian. David

Cheers Danny. I will start looking for some suitable forked oleo legs to experiment with. They need to be able to take 3.5" wheels which seems to limit choice a lot (well at least in the affordable price range it does)

Great job Cliff. Looking forward to the maiden flight. David