Danny Fenton Posted October 11, 2014 Share Posted October 11, 2014 I think the higher kv is a good solution or up the cell count?I am afraid tomorrow is looking very doubtful, its one of my favs too. Weather gods will hopefully shine down on you CheersDanny Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted October 11, 2014 Share Posted October 11, 2014 Congratulations Lindsay, it looks the part, very atmospheric. Quote Link to comment Share on other sites More sharing options...
Tony Bennett Posted October 11, 2014 Share Posted October 11, 2014 wonderful. didnt think it was going to get off though at first. Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted October 11, 2014 Author Share Posted October 11, 2014 Many thanks guys, take off run was a bit long, the wet grass did not help but she was tracking true and I was progressively adding up elevator so she did not suddenly leap into the air, particularly with the power being a little on the low side. Mods - perhaps we can change the thread title to DF2 Flycatcher Linds Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted October 11, 2014 Share Posted October 11, 2014 I saw the DF2 this morning and she looks even nicer "in the flesh"! Great job Linds. With a tad more "umph" it'll be a beaut. BEB Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 11, 2014 Share Posted October 11, 2014 Thought Mort handled it very well Lindsay, congratulations John Quote Link to comment Share on other sites More sharing options...
Stephen Jones Posted October 11, 2014 Share Posted October 11, 2014 Looks good to me , I would try a 3 or 4 bladed Prop before going for a high Kv . It just would not sound right a slow old timer with a screaming motor . Steve Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted October 12, 2014 Share Posted October 12, 2014 Is it a co-incidence that by calling it a DF2 Flycatcher you have almost turned it into a Fairey? Not sure that a three bladed prop would look right on this though, a four blader would be more realistic because some of the early kites did use them, but a three would be really off the wall appearance wise, for me. Quote Link to comment Share on other sites More sharing options...
Tim Hooper Posted October 12, 2014 Share Posted October 12, 2014 Just caught up with this one! Looks great Linds. tim Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted November 1, 2014 Author Share Posted November 1, 2014 Couple of mods including a change of motor to a 1250kv has brought the power up to 320watts on an APCE 10x3.8 prop so should now give a good bit more power. Since I have been waiting for some descent weather for another test flight I have made a couple of other additions. The first being a balsa air scoop that sits over the top of the motor and ensures cool air passes over the top area for added forced air cooling. This is just made up of 3mm balsa and glued to the top surface of the wing across the centre area cut away. I also made some little details to the front dummy fuel tank with the addition of some leather retaining straps and a dummy fuel cap made from a domed wire end fitting. More details vid and pics following the next test flight but hopefully she is just about done. Linds Quote Link to comment Share on other sites More sharing options...
GrahamWh Posted November 2, 2014 Share Posted November 2, 2014 It really does look great. Is it possible that the plate behind the pilot's legs is acting a little like a down pointing elevator causing the long take off? Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted November 2, 2014 Author Share Posted November 2, 2014 Hi Graham, I think the long take off was primarily down to a lack of power, although I have reduced the down thrust on the motor from 3 degrees to 11/2 which may have also been contributing. The truth is of course without the use of a wind tunnel and modelling the surface areas and drag coefficients we will never know for sure its effect but from a pilot feel perspective it did not seem to be creating any strange pitch effect and indeed once airborne, suffice for the need for a little up elevator trim at full power, hence the reduction in thrust line, she was remarkably stable and steady. The next flight with improved power should conclude the basics I hope and I can start to experiment the flight envelope although inverted passes might look a little odd. Linds Quote Link to comment Share on other sites More sharing options...
GrahamWh Posted November 2, 2014 Share Posted November 2, 2014 I look forward to seeing another flight video Linds. It is rare to see such a fine looking, out of the ordinary model. It really looked great in the air too. Quote Link to comment Share on other sites More sharing options...
GrahamWh Posted November 8, 2014 Share Posted November 8, 2014 Linds, would it not need more down thrust rather than less with the motor as a pusher so the line of thrust runs closer to the centre of drag? A bit like the Hobby King Bixler and other high engine pushers? Edited By GrahamWh on 08/11/2014 21:54:12 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted November 8, 2014 Author Share Posted November 8, 2014 Hi Graham, as with all things it's never as simple and a factor of multiple issues not least of which wing section, incidence, model weight, centre of gravity, air speed, lift coefficient and factors of drag all contributing so without mathematically modelling and for that matter hiring someone like BEB to work it all out for me, and yes he would probably enjoy that, it's often following some basic rules and post flight trimming to fine tune. many years of flying F3A no doubt assisted me in fine tuning a models performance. With something like Flycatcher I think gut instinct in fine tuning is probably the safest way as she already fly's pretty well and I just want to dial out minor issues so we have a stable base point that can be defined on the plan. If you watch the video you can see on the slow pass the model has more up elevator held in than we would expect, and when the power was opened up more was required to climb away indicating a down force excess from the motor. The first flight also was with quite a forward cg for safe performance and this can be tweaked a bit too now. Will hopefully get some more flight in soon and close off the design process. Linds Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted November 9, 2014 Share Posted November 9, 2014 If you're doing inverted passes I hope Mort has a good grip on that stick! Looking forward to a long awaited maiden pt 2. Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted January 2, 2015 Author Share Posted January 2, 2015 Well finally got out to test the updated motor and glad to say complete success, much more power and safer operation, removed a degree of down thrust completed the package. I was using a 2200 3cell so have lost a little duration but there is space for a larger pack, probably up to 3000mah so should not be an issue. Only problem was that I forgot to take my camera so no pics or vid yet but will get this next time. So I'll now get cracking on the plan and write up and see if the Ed is interested. Linds Quote Link to comment Share on other sites More sharing options...
Kevin Fairgrieve Posted January 3, 2015 Share Posted January 3, 2015 He better be interested!! Kev Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted May 12, 2015 Author Share Posted May 12, 2015 All mag photos now completed on Flycatcher. All shot on a pretty gusty day when most sensible people would have stayed grounded but having waited literally months before I could get together with Alex on the same day and the light being good we decided to go for it anyway. Flycatcher proved to handle the 25-30mph winds with surprising ease, perhaps the benefit of very little side area played a bonus. I promise to get some more photos and video posted soon but nice to get the project finally completed. Linds Edited By Lindsay Todd on 12/05/2015 23:57:42 Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted May 27, 2015 Author Share Posted May 27, 2015 During last weekend at Greenacres we noticed a little crack in the lower fuz longeron, not sure if this occurred in transit or otherwise anyway a small gusset adds a huge amount of strength just in case as an addition to the future plan and any prospective builders. Thanks Tim for spotting it Linds Quote Link to comment Share on other sites More sharing options...
Chris Barlow Posted June 5, 2015 Share Posted June 5, 2015 Video from Greenacres May funfly. The more I watch it flying the more I like it! Mort is pretty cool too sat perilously up front! Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted June 5, 2015 Author Share Posted June 5, 2015 Excellent vid Chris, many thanks for posting that. Linds Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted June 5, 2015 Share Posted June 5, 2015 That really does fly a treat, congratulations on another successful design Lindsay and also Chris on the excellent video. It really captures the very early vintage look and the resemblance to the Demoiselle is definitely there. It looks a lot faster than I expected, with a scale speed that seems like about 200 mph! I can imagine that Mort's eyes must have been really watering! I wish I had been able to get to Greenacres to see it, but it co-incided with my wife's birthday and I didn't dare to suggest it. If you stick it on floats it might make a good facsimile of an early Schneider Trophy seaplane! Actually, it would make a very interesting seaplane for our mates who fly off water, a pair of the early boxy type floats with a small one at the rear would really look the part. Playing it back on my IPad it sounds surprisingly loud. Is that an illusion or something to do with the characteristics of the open airframe design? Perhaps it sounds completely different to that in real life. Quote Link to comment Share on other sites More sharing options...
GrahamWh Posted June 5, 2015 Share Posted June 5, 2015 Great model Linds - been looking forward to seeing that. Quote Link to comment Share on other sites More sharing options...
Lindsay Todd Posted June 5, 2015 Author Share Posted June 5, 2015 Hi Colin, funnily I was talking about how she might look with floats only this afternoon as a friend of mine has a large seaplane ready for test and we were thinking about other models to play with. The weather at Greenacres was so calm that slowing her down was not so easy, also I was flying her with the original wing which is 48" span which I replaced with a 54" version as the proportion just looked more balanced but the original proved to be almost as good flight wise and we used it for flying in a howling gale the week before and I had not swapped it over so she fly's just a little faster on the shorter wing and a tad more nose heavy as well. The noise is not quiet so bad as the video suggests but it is the result of my prop and motor combination in the pusher format. I guess moving to a 3 or even 4 blade prop might improve things but I'm quite happy with the result. The model has proved to be great fun to fly. Linds Quote Link to comment Share on other sites More sharing options...
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