John Timmis Posted March 22, 2020 Share Posted March 22, 2020 HI Thi present enforced isolation does mean that there is time available for building activity. With the Chiltern just about finished , apart from a few details, it seems like a good time to pick up some unfinished projects. The first one is an own design EDF Vampire. This has been gathering dust for about the last 6 or 7 years. It was put aside when I joined in with Danny's Chipmunk build. Most of the construction has already been done so this is where I am at the moment. This is actually the 2nd Vampire I have made, but more of that later. cheers John Quote Link to comment Share on other sites More sharing options...
Gordon Whitehead 1 Posted March 22, 2020 Share Posted March 22, 2020 That's a super project to resurrect John. What are the specs? It looks as if it might be for a 90mm fan, so a really nice size. Cheers Gordon Quote Link to comment Share on other sites More sharing options...
John Timmis Posted March 23, 2020 Author Share Posted March 23, 2020 Hi Gordon, everyone, Yes it will be good to get this one finished. My first Vampire was made 9 years ago .It was my first attempt at an own design EDF. It flew very well, the glide seemed to go on for ever, it even had the characteristic Vampire whistle. For several years it hung on the garage wall until last year I decided to fly it again. Unfortunately I forgot to put in the extra lead in the nose. DO'NT FORGET THE PRE FLIGHT CHECKS, Say no more. Model specs; 49" wingspan, 70mm wemotec fan, 4s 3200 lipo. I think the weight was in the region 31/4 lbs but it was a long time ago. Cheers John. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted March 26, 2020 Author Share Posted March 26, 2020 Hi everyone hope you are all well & finding some modelling time to get on with your projects. Here are a couple more photos of the original model. There were four issues I wanted to improve on the new model: 1 the rather untidy radio instalation with its multitude of hatches, 2 The inconvenient battery connection, the lead had to be threaded through & the large hatch removed for each flight, 3 a better & less complicated fuselage construction, 4 Move the fan forward to remove the need for lead in the nose. Positives were : it did fly well, looked good in the air, scale size intakes , no cheat holes , only the exhaust size slightly enlarged. Next time I'll show some progress on the new model. cheers John Quote Link to comment Share on other sites More sharing options...
Steve Adams Posted March 26, 2020 Share Posted March 26, 2020 Absolutely fantastic and congratulations John, you could always share your design and draw a plan for a certain magazine...only if you want to though 😊 How about a Venom as a follow up? Kind Regards Steve 😁 Quote Link to comment Share on other sites More sharing options...
John Timmis Posted March 28, 2020 Author Share Posted March 28, 2020 Hi Steve, everyone, Thanks for your comments Steve, glad that you like it. These early jets have always been favourites of mine, takes me back to when I was a lad. I remember reading about PE Norman"s early ducted fan models back in the 50's. I think I first saw edf at the Western Park show about 15 yrs? ago. Anyway that's what inspired me to take up RC again after a 25 year layoff during which time I was involved in schools karting & full size gliding. Back to the model. Some progress has been made. The top wing skins have been fitted, the tail booms have hade the sides glued on & shaped, the elevator snake has been installed. The elevator servo has been fitted in the wing root. Really it's a case of getting all the various bits ready for a final assembly. Looking at the fuselage photos. The fuselage behind the fan frame is all .4mm ply. The rear duct is a short cylinder & then a truncated cone to the exhaust. In front of the fan frame, the fuselage is a basic box structure of 1/4 sq balsa with additional formers to make up the outside profiles. It's certainly not a typical fuselage. As far as i can remember the build sequence was first to build the rear duct with the fan / stub spar frame flat on the building board & the duct vertical. The forward fuselage is an ordinary balsa frame structure. These were then glued together & the wing root ribs added. The wing roots were then built on. Altogether a bit involved & care needed to ensure a straight fuselage. Into all this the glassfibre ducts needed fitting. Something of a jigsaw puzzle. More about the ducts nex time. Cheers John Quote Link to comment Share on other sites More sharing options...
John Timmis Posted April 4, 2020 Author Share Posted April 4, 2020 Hi everyone, the ducts. As we all know, ducted fans are muck less efficient than props. It seemed to me that getting the ducting right was an essential, & also very interesting part of model. Not having designed an EDF before, I read around on this & the other model forum. The accepted wisdom seems to be; ducts should be as straight & unobstructed as possible, avoid sharp bends & changes in direction, a rounded duct inlet is better than a sharp inlet, losses a greater in long ducts. The sizes of the inlet & outlet are critical & are based on the FSA (fan swept area). The inlet needs to be 100% FSA while the outlet can be reduced a bit , from memory 80 %. As shown in the photos the ducts were molded from glassfibre ( glass cloth & epoxy resin, the same stuff I use for finishing). So, here is 'Here is how I done it" The molds are made from pink foam. They were profiled on the bandsaw, templates for the inlet & outlet glued to each end & then the bit in the middle was cut & sanded to a smooth profile. The shaped molds were then covered in solarfilm. Several laminations of glass cloth & epoxy rein were applied. While the moulding was still in its green state it was slit down one side & rmoved & then replaced on the mould to cure. The cut edges were glued with cyano & then another layer of glass. Hope it all makes sense. cheers John Quote Link to comment Share on other sites More sharing options...
John Timmis Posted April 14, 2020 Author Share Posted April 14, 2020 Hi everyone, Hope everyone is well & busy building. Progress on the Vampire is steady rather than rapid, but there is no rush. I try to do a bit every day to keep it moving forward. All the various components are done so now it's time to start assembling them all. Should begin to look like a Vampire. The fuselage was sheeted round the nose & the belly, rather than planking. The trick with ammonia helped to get the wood round the double curvature. The tail booms were built with a vertical .5mm ply diaphragm from wing leading edge to tail. The idea is to make it easy to keep everything aligned during assembly. Cheers John Quote Link to comment Share on other sites More sharing options...
John Timmis Posted April 18, 2020 Author Share Posted April 18, 2020 Hi everyone Well that's gone together quite nicely. It looks like a Vampirre now. I've just given it a coat of clear dope, so next is a good all over sanding & then get it glassed. The weight as seen , with a 4s battery but no esc is 3lb 4oz, seems about right Stay well. Cheers John Quote Link to comment Share on other sites More sharing options...
Timo Starkloff Posted April 19, 2020 Share Posted April 19, 2020 What a nice Vampire, magnificient Timo Quote Link to comment Share on other sites More sharing options...
Stephen Belshaw Posted April 19, 2020 Share Posted April 19, 2020 Lovely job. I'm also a fan of the "golden era" jets, many happy memories of seeing them in action at Hucknall Aerodrome. Quote Link to comment Share on other sites More sharing options...
Gothiquity Posted April 19, 2020 Share Posted April 19, 2020 Looks excellent John. Always loved this era of Jets. Shame we hardly see the the real ones flying anymore. Have you chosen a colour scheme, yet ? keep safe, and happy modelling Goth Quote Link to comment Share on other sites More sharing options...
John Timmis Posted April 21, 2020 Author Share Posted April 21, 2020 HI Thanks for the comments, it's always nice to get some feedback. Timo, glad you like it, I take that as a compliment coming from you. Love the Whirlwind. Stephen & Goth, when I was at school we always had our eyes up in the sky. Every day you would see Vampires, Meteors, Spitfires, DC3, Anson, etc. Happy days. Colour scheme is in the future but it might be similar to the first model. That seemed to show up quite well in the sky. The rubbing down is done so now it's on to the glassing. Yesterday I ran the C/G finder programme & it will need a little weight in the nose. Since my 4s lipos are past their best I looked for something just a bit bigger on HK. The best lipo was just a tad too wide to fit through FI. So the side cheeks of the nose had to be split off & the hole in Fi englarged with the Dremel & a file. Didn't plan on that but it's done now. Cheers John. Quote Link to comment Share on other sites More sharing options...
Outrunner Posted April 21, 2020 Share Posted April 21, 2020 Hello John. I love the Vampire and I love your Vampire model. Great work and thank you for sharing. Will there be a plan? It looks too good for there only to be one of these flying around. Hopefully this lockdown will be over soon and you can fly your Vampire. I have one new model and two rebuilt models ready to fly. I can't wait. Stay safe. Phil. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted May 22, 2020 Author Share Posted May 22, 2020 Hi all, hope everyone is ok. Here are a few more photo's to show the latest progress. I find glassing a great way to finish models, though it does take quite a long time. Not helped when I got out the glass & found that I only had enough for the tailplane. Anyway it's all done now. Just needs some colour now though that will probably have to wait until I can get to the shop. Phil, can't see there being a plan. I downloaded a 3view of the Vampire & got it enlarged to modelsize. It has turned out to be 49" wingspan, it was all more or less decided by the size of the fan. Apart from drawing a wing plan the rest was done from the enlarged 3 view with much of it evolving as the build progressed. Still needto put some weight in the nose & then it's good to fly. Have to get my thumbs working again first. Cheers John Quote Link to comment Share on other sites More sharing options...
stuey Posted May 22, 2020 Share Posted May 22, 2020 Looking good Quote Link to comment Share on other sites More sharing options...
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