Nigel R Posted October 12, 2019 Author Share Posted October 12, 2019 Thank you gents. Paul it is quite similar and before starting this project I was fifty fifty on doing my own design or getting a twin scorpion. Right then. A couple of hours on trim has got me thus far: Getting there... Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted October 13, 2019 Share Posted October 13, 2019 That's looking the mutt's nuts now Nigel. Can't help thinking what a nice electric model it would make with battery access through the nose Quote Link to comment Share on other sites More sharing options...
Mark Elen Posted October 13, 2019 Share Posted October 13, 2019 Hi Nigel, That looks beautiful mate. Well done. Don’t start thinking about the ‘dark side’ as Bob alludes to 😂😂😂 Cheers Mark Quote Link to comment Share on other sites More sharing options...
Nigel R Posted October 13, 2019 Author Share Posted October 13, 2019 Quote Link to comment Share on other sites More sharing options...
Nigel R Posted October 13, 2019 Author Share Posted October 13, 2019 Last segment of the sunburst done. Appreciate the comments gentlemen. No chance of going to the dark side for this one mark! Although I could be convinced to re engine it one day with a pair of four strokes... Quote Link to comment Share on other sites More sharing options...
Nigel R Posted November 4, 2019 Author Share Posted November 4, 2019 Setup day for the engines. Found that the starboard is about 400rpm weaker than the port. I'm not sure why, perhaps it is a bit more worn. Otherwise, a bit of adjusting and they both idle at a notch over 3k rpm. Full throttle on the 10x6 is 11k (port) and 10k6 (starboard). Quite happy with that, I don't think the difference at full chat will be noticeable in terms of flying characteristics. Quote Link to comment Share on other sites More sharing options...
Jon H Posted November 4, 2019 Share Posted November 4, 2019 Dont worry so much about full throttle rpm. Its all about the mid range where i would aim for +/- 200 if at all possible. The other thing to remember is that it will all change in flight anyway so just get it in the air and see what happens. If one sounds rich, lean it a smidge for the next flight and go from there. My old Pilot twin ace had 25fp's in it and they were a mile out of whack on the ground. Once in the air and a circuit or two in they came on song and ran together very sweetly. Quote Link to comment Share on other sites More sharing options...
Nigel R Posted November 4, 2019 Author Share Posted November 4, 2019 Thanks Jon. I didn't tacho the mid range but it sounded quite close, and pickup was even. I'm waiting on a noise check before getting airbourne now. Quote Link to comment Share on other sites More sharing options...
Timo Starkloff Posted November 4, 2019 Share Posted November 4, 2019 Good luck Nigel for the first flight! The nacelles are close to the fuselage, motor size seems not to be oversized, fuselage sufficiently long and rudder big enough. Should fly fine on single engine. And with that big wing you should be able to reduce power on the remaining one if the other fails, and still keep flying. Not too much wind helps in that case. Keeping a good speed for good control response is a suggestion I would give, the slower you are the more difficult it is to conquer a failing motor. Never had a twin were the rpms mattered. In fact, I never measured them. Take a setting were each motor is running fine. It only gets interesting if one quits completely. Differences don’t matter when the model flies at speed and your rudder is therefore efficient in keeping the course. Timo Quote Link to comment Share on other sites More sharing options...
Nigel R Posted November 4, 2019 Author Share Posted November 4, 2019 Many thanks Timo I forgot to add a few figures - the final weight minus fuel is 6lb 9oz (3kg) and wing area is just over 700sq in. Loading is 22oz/sq ft. Cubic loading, for those that take notice of it, is 9.6 oz / cu ft. Quote Link to comment Share on other sites More sharing options...
cymaz Posted November 4, 2019 Share Posted November 4, 2019 WCL is just about the aerobatic range of 9-10 Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted November 4, 2019 Share Posted November 4, 2019 I've been following your build thread since the beginning, Nigel. ... and of course the numerous 'calculations' for your 'peace of mind' and final decisions. A great self-designed achievement and wishing you the very best with your maiden. Cheers Chris Quote Link to comment Share on other sites More sharing options...
Nigel R Posted November 17, 2019 Author Share Posted November 17, 2019 Thank you gents Maiden day yesterday! First up was the mandatory noise check. Our club has a strict policy of no pass = no fly. With the Graupner props it was a fail. Not by much but a fail is s fail. Interestingly the direction of the highest reading was from in front so I can only assume the bulk of that was prop noise. From behind it was well within in fact that direction was the lowest reading. I think one engine would have been quiet enough but the two together... Anyway I had a pair of APC 11x6 as backups and with those fitted the readings dropped by about 3db in each direction. That was enough to secure a pass so I will run with these props. Range check ok. Nose up test ok. Controls moving the right way - no more excuses. Take off was not exactly what I'd hoped for. Of late the runway has been rather wet and a little less maintained compared to its usual immaculate condition. This meant a number of sheep offerings were present and I had to aim between them. This was all good for the first part of take off until a hitherto unseen lump of turd jumped in front of the starboard uc leg and sent the model careering towards the rough at high speed. Abort? No time to think as she bumped the long grass the nose went up and she was away and accelerating rapidly without the drag of the soft muddy strip to slow her. After getting things back on track by aiming her into a little more gentle climb she was revealed to be pleasantly in trim bar a couple of clicks down elevator. Controls were nicely harmonised. A touch more rudder movement will be needed by elevator and aileron were spot on. After a few circuits some basic aeros showed good manners and a reasonably good balance point. She would snap and spin with clean recovery. Stall turns were a little slow but a little more rudder will cure that. Inverted needed a touch of down - just right. The engines need a little tweak I think. Despite the ground tests one started to die back during a stall turn so a minute adjustment needed. After a few minutes it was time to think about bringing her back down so I flew a couple of circuits at height before coming down for finals. She slowed down beautifully and floated in with no drama. The only hairy moment was when I realised this model is larger than the rest of my fleet and I was about to land the far side if the strip. Open up slowly, go around, line up again, and down for a nice bounce free arrival. Perfect All I need to do now is find some spinners to fit the APCs. Edited By Nigel R on 17/11/2019 08:40:03 Quote Link to comment Share on other sites More sharing options...
Jonathan M Posted November 17, 2019 Share Posted November 17, 2019 Well done Nigel - your account of the maiden session was a delight read! Quote Link to comment Share on other sites More sharing options...
cymaz Posted November 17, 2019 Share Posted November 17, 2019 Hoorayyyy Quote Link to comment Share on other sites More sharing options...
Denis Watkins Posted November 17, 2019 Share Posted November 17, 2019 Yahoooooo. Well done Quote Link to comment Share on other sites More sharing options...
Piers Bowlan Posted November 17, 2019 Share Posted November 17, 2019 Good news indeed. Congratulations, a well deserved success . Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted November 17, 2019 Share Posted November 17, 2019 Great Stuff!! Quote Link to comment Share on other sites More sharing options...
Bob Cotsford Posted November 17, 2019 Share Posted November 17, 2019 Now that would make a good 2 part free plan. Keviiiinnnnn! Do we have a Mr Crozier in the house? Quote Link to comment Share on other sites More sharing options...
Dad_flyer Posted November 17, 2019 Share Posted November 17, 2019 Well done . It has been interesting to watch the build. Quote Link to comment Share on other sites More sharing options...
Timo Starkloff Posted November 17, 2019 Share Posted November 17, 2019 Congratulations! Not many people get the experience of flying an ic twin. Something unforgettable, especially when both motors are running fine. So good luck for your next flights and keep on training. The more hours, the safer you feel. Timo Edited By Timo Starkloff on 17/11/2019 17:19:43 Quote Link to comment Share on other sites More sharing options...
Nigel R Posted November 17, 2019 Author Share Posted November 17, 2019 Thank you all - that twin sound is something else. I'm dead chuffed with the end result As Hannibal (nearly) said, I love it when a plane comes together! Quote Link to comment Share on other sites More sharing options...
Nigel R Posted December 8, 2019 Author Share Posted December 8, 2019 Quote Link to comment Share on other sites More sharing options...
Nigel R Posted December 8, 2019 Author Share Posted December 8, 2019 Quote Link to comment Share on other sites More sharing options...
Nigel R Posted December 8, 2019 Author Share Posted December 8, 2019 Quote Link to comment Share on other sites More sharing options...
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