Chris Bott - Moderator Posted February 4, 2018 Share Posted February 4, 2018 Thanks Percy. No the Rapide is not for me I already have enough pointy wings ta. Chris I can only encourage the drawing up of the plans. It would certainly go straight in near the top of my to do list. Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted February 11, 2018 Author Share Posted February 11, 2018 Not so much progress this week. The battery box is in, and I have made up the giant block of balsa that will eventually become the shapely Dragon nose. This will be removable for battery insertion. Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted February 14, 2018 Author Share Posted February 14, 2018 I may never carve a nose block from the solid ever again!! However, it's come out not half bad. Quote Link to comment Share on other sites More sharing options...
cymaz Posted February 14, 2018 Share Posted February 14, 2018 I congratulate you on your efforts Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted February 28, 2018 Author Share Posted February 28, 2018 Slowish progress again this week. Busy elsewhere, and chilly in the workshop. The two centre section wing mounts are done, and the 1/16" fuselage side skins made up so that the window openings can be cut out before they are fixed. The tray for the tail servos and receiver are in, and I've also purchased a 1/10 scale latex pilot who fits the cockpit well. The wing mount location took time as the wing centre sections had to be sanded to shape to fit the fuselage and define the points for their mounting screws. I will use my usual wing mount system. Two steel pins at the front that are set strongly into the leading edge, and engage with holes in the ply bulkhead, and two screws and blind nuts at the rear. I'm never sure whether I should do the design work on paper first, or make the detail fitting of small parts up as I go along, and draw it later. In the case of the Dragon, the lower wing lifts upwards against substantial fuselage members, but the upper wing doesn't have much structure to hang on to. I've probably over engineered mounting it a bit, but better too strong. In any case, the lift will be shared across the two wings, and the model won't pull a lot of "g" ever. Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted April 5, 2018 Author Share Posted April 5, 2018 Slow but meaningful progress in the last few weeks, interrupted by a birthday reminding me of the advance of anno Domini, but with the compensation of spending it with grandchildren. The Dragon has got to the stage where 90% of it is built, but finishing it will take as much time as has been spent so far. The main task recently has been completing the removable nose which has come out pretty well. The original aircraft cockpit appears in two forms, one with the roof finished in white, and the other glazed. I imagine the roof glazing would have been the way it came out of the factory and, since I have fitted a pilot and a photo image of the real instrument panel, I am going to glaze mine. The removable nose plugs into four holes in the main bulkhead with locating pins, and secured by four very strong magnets which click on to four countersunk screw heads. I don't think it will blow off! I have also found room for a LED nose landing light powered by two AAA cells. When designing a model, especially one that approaches scale, the easy bit is achieving an outline which will stand friendly scrutiny. Once you have an outline, designing the structure to support it can often pose problems. The temptation is to put off the really tricky bits, and hope inspiration for a build solution appears out of the blue; which it often does. The undercarriage design looked difficult, but I'm pretty sure I have a mental design that will work. Similarly, the wing fixing to have permanently rigged outer wing panels will follow something I have done before. The engine nacelles had me stumped for a while. They are complex shapes, curved all over and with non parallel sides with the undercarriage suspension units going up into them. However, they are very distinctive Gipsy Major shapes, and vital to the final appearance, so they have to be right. I think I've got the design sorted, and I've kitted some of the structure. Hopefully, the build will work out. Quote Link to comment Share on other sites More sharing options...
Fun Flyer Posted April 5, 2018 Share Posted April 5, 2018 Could this be considered as a canditate for the Free Plan in the Autumn Special? (Or does it have to be yet another Warbird) Quote Link to comment Share on other sites More sharing options...
Fun Flyer Posted April 5, 2018 Share Posted April 5, 2018 Lovely piec of work by the way Chris. Quote Link to comment Share on other sites More sharing options...
TJ Alexander Posted April 5, 2018 Share Posted April 5, 2018 Posted by Chris Reid on 05/04/2018 19:44:22: Slow but meaningful progress in the last few weeks, interrupted by a birthday reminding me of the advance of anno Domini... Surely you mean Anno Dominie? Quote Link to comment Share on other sites More sharing options...
onetenor Posted April 5, 2018 Share Posted April 5, 2018 My mum and dad went on their honeymoon in Rapide (DRAGON) and mum said that as she was biggish lady she was asked to sit alongside the pilot to aid correct C/G. Is that actually possible? Are there two crew seats? BTW that was Sun 15th Sep '40 and we all know what that day was don't we ? Edited By onetenor on 05/04/2018 23:48:36 Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted April 6, 2018 Author Share Posted April 6, 2018 Thanks for the comments guys. I daresay our worthy editor may offer to have me produce a plan for the Dragon, but I'm not sure I can face the task as it's a complicated build that will be a lot of work to draw up properly. I am making build notes and taking build photos so t's a possibility. "Dominie" is a great pun. I thought of making a Dominie so that I could do it in war camouflage, but the Dominie is a Rapide in drag, and I didn't want to do those pointy wing tips. Both the Dragon and the Rapide are single pilot aircraft so the larger mum must have been asked to sit up front rather than by the door. My model cockpit is slightly wrong in that access to the cockpit in the real aircraft is by a narrow opening at the right hand side of the central pilot's seat. My design used two identical bulkheads for fuselage battery box access and the cockpit rear - I spotted the error too late to go back, and in any case I go for reasonable scale appearance without going overboard on exact detail. My DH 60 Moth, pictured earlier, cured me of that. Super scale detail adds lots of work which you can't see when the model is flying. CR. Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted April 9, 2018 Author Share Posted April 9, 2018 Well the nacelles kit of liteply formers and 1/8" sheet balsa sides looked like a good idea, but didn't work out in practice. The first problem was that the bendability of the sheet sides wasn't consistent, and they didn't bend equally when tensioned with rubber bands. Secondly, after being bent for a while they tended to snap at the narrow portion. I had a couple of goes making stronger sides, but the design was obviously flawed, even painting the sides with water didn't help: it just took longer before the snap occurred. And so to plan B. I'm going for that old favourite, lamination on a shaped former. I'll use two layers of 1/16" or possibly 3/32" sheet, and a grade that will bend easily on to the former. The PVA glue sticking the laminations together will help with the flexibility. Once the PVA is dry, the sheet sides will have taken up the proper curve with no excess strain. I should have thought of this from the outset, but hoped to avoid the labour of a former. Sanding a big lump of MDF to the final shape took a little time! Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted April 10, 2018 Author Share Posted April 10, 2018 So far so good! The laminating system works. It will come out of the airing cupboard later. CR Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted April 12, 2018 Author Share Posted April 12, 2018 Deep joy! The lamination of the side members of the nacelles has worked perfectly. The built in curve is just right, and the formers slot into place with only the lightest of pressure from rubber bands to hold them in place. Next step will be to glue them together, install the motors, and make access hatches and the stringered upper surfaces. CR Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted April 13, 2018 Author Share Posted April 13, 2018 The nacelles have all gone together pretty well. I've spotted a minor design glitch that will have to be worked around, but nothing that can't be fixed. Rounding off the upper surfaces, and final finishing should be straightforward. Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted April 23, 2018 Author Share Posted April 23, 2018 The nacelles are done. There was some design work to do as their build advanced and, if the project becomes a magazine plan, I will simplify what I had to do to get things to come out as they should. That said, I am well pleased with the outcome. After final finishing, they will look the part. Quote Link to comment Share on other sites More sharing options...
Timo Starkloff Posted April 23, 2018 Share Posted April 23, 2018 Very nice! Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted April 26, 2018 Author Share Posted April 26, 2018 Now the engine nacelles are finished, I have got back to the bigger bits. The wing mounts are in, and I've got to planning the wiring of the lower wing which will carry leads for motor power, esc, and aileron servos outboard of the wing joint. I have made up the battery wiring with plug connectors, but inevitably I didn't have enough male 4mm plugs for the female ESC connectors so Ebay will be supplying more. I've also installed the ply plate that will carry the undercarriage on the lower centre section. A step forward with the fuselage was adding the 1/16" sheet sides. The windows were glazed on the inside after painting the window edges red to match the red hobbyfilm covering to be added later. I made an experimental window and found that the film can be ironed on to the window edges and then the glazed area exposed by careful removal of the film with a sharp blade. The next tasks will be the wing joiners, sorting the closed loop cables for the elevators and rudder, and sheeting the fuselage top and bottom. Quote Link to comment Share on other sites More sharing options...
michael harper 2 Posted April 28, 2018 Share Posted April 28, 2018 Looking good and a big fan of DeHavilland aircraft. I'm looking to start the Dale Tattam DH Tiger Moth and the Dumas Dragon Rapide. If you want any help drawing up plans, give us a shout, can do it on computer using Microstation. Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted May 29, 2018 Author Share Posted May 29, 2018 Thanks for the offer Michael, maybe I'll take you up on it. I have flirted with CAD in the past but like all software, learning it in the first place, and then not forgetting the detail is a pain. Also, I can't cope with designing on a small screen, so big sheet of paper and a drawing board it is. I learnt engineering drawing nearly 60 years ago and I'm now too old a dog for new tricks. The Dragon proceeds. The cockpit has been glazed, it was a bit fiddly but it has come out well. The secret was to use very thin material which coped with the curves. I use Pacer Formula 580 Canopy Glue. It's thin like water, dries transparent, and really holds well. The basic undercarriage fixing to the lower wing has been designed and built, and the 16 wing joint fixings for the plug in outer wings done. I'm using alloy tube and carbon rod as joiners. The pic shows the first fix with cyano to locate everything in position. The tube/rods are now bonded to the spars with glass cloth and epoxy. Big day this morning with a first assembly of all the bits. Everything goes together OK, and the model does look like a Dragon. Lots of work still to do with detail fitting, wiring, and finishing, but the end is in sight. Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted May 29, 2018 Share Posted May 29, 2018 Ooh isn't that nice! Quote Link to comment Share on other sites More sharing options...
Former Member Posted May 29, 2018 Share Posted May 29, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted May 29, 2018 Author Share Posted May 29, 2018 I haven't weighed it yet Percy as there's still quite a lot to do. I tend to overengineer my designs a bit, which is a mistake as crashproof models can't be done. So it may weigh a bit more than it could. However, I always build in plenty of electric grunt which cures all ills! Edited By Chris Reid on 29/05/2018 16:30:13 Edited By Chris Reid on 29/05/2018 16:31:04 Quote Link to comment Share on other sites More sharing options...
Former Member Posted May 30, 2018 Share Posted May 30, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Chris Reid Posted May 30, 2018 Author Share Posted May 30, 2018 Hi Percy, Agritug is indeed one of mine, and one of my most regular fliers for its nice airborne manners. My latest," Mignon", is another up coming favourite for the same reason; although to be fair it is a steal from Chris Foss's Wot 4. I am coming to favour smaller simple models, although "close to scale" aircraft (as is Agritug) have featured a lot in my past. I'm guessing that Dragon may be my last go at a pretty complex model. I have been taking build photos and writing up the construction methods with a view to publication, although the detailed drawing required will be a big task. David Ashby has encouraged me so I think it will become a project later this year. I will have to fly Dragon first, and with several holidays coming up, completion won't be for a while. Biplanes do look larger, and its not to much of an illusion because they have twice the wing that they really need. An outcome of their wire braced box structure. Dragon is 60" span because she has to fit into the back of my SEAT Arona. (I prefer smaller cars too). Quote Link to comment Share on other sites More sharing options...
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