Former Member Posted October 5, 2018 Share Posted October 5, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted October 5, 2018 Share Posted October 5, 2018 Nice job David. Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted October 5, 2018 Share Posted October 5, 2018 Yes - 60W/ib is plenty for a model like that I think. It is so easy to over power them and they don't fly right like that.. Lovely job by the way! BEB Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 5, 2018 Author Share Posted October 5, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
David Davis Posted October 5, 2018 Share Posted October 5, 2018 Nice job David. Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 5, 2018 Author Share Posted October 5, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
kc Posted October 5, 2018 Share Posted October 5, 2018 David, i think most people measure watts with a watt meter at full throttle on the ground, then use that figure for watts per pound. Probably not the same way you calculate? So what would your motor give measured with a watt meter? What is the laminating film you use and how is it applied? Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 5, 2018 Author Share Posted October 5, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 5, 2018 Author Share Posted October 5, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted October 5, 2018 Author Share Posted October 5, 2018 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Biggles' Elder Brother - Moderator Posted October 5, 2018 Share Posted October 5, 2018 It is amazing just how little power you can fly on isn't it! I've said it before I think these days we (all) have a tendancy to overpower - becuase we can! It's nice to see what is possible though on so little "umph"! Put a 2200 in it and you'll be up there all day! BEB Quote Link to comment Share on other sites More sharing options...
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William Macleod Posted October 5, 2018 Share Posted October 5, 2018 mine has a 3s 3500 lipo and flies for about 15 mins, including touch and go circuits, and still has 38% left. Magic machine bill Quote Link to comment Share on other sites More sharing options...
McG 6969 Posted October 5, 2018 Share Posted October 5, 2018 Really splendid, David. If I wasn't already involved in my Vicomte build and in the upcoming Fury Classroom, I would certainly have a go at a Junior or even a Super. Absolutely well done. Cheers Chris Quote Link to comment Share on other sites More sharing options...
PatMc Posted October 5, 2018 Share Posted October 5, 2018 Posted by David Mellor on 05/10/2018 17:48:20: So..... how many Watts Per Pound does it need to fly??? The answer - based on 9 flights of 15 minutes duration each (using 3S 1500 mAh Zippy compact Lipos) - is 48 Watts in total. Since the weight is exactly 2.5 pounds, the Watts-Per-Pound figure is just 20 Watts-Per-Pound, based on two hours and 15 minutes of flight time this afternoon. That figure includes ROG and climbing to about 300 feet for cruising at the Junior 60's famous "single speed". I don't understand your maths here, David. Where does the 48 Watts total come from ? Quote Link to comment Share on other sites More sharing options...
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PatMc Posted October 6, 2018 Share Posted October 6, 2018 Hi Dave, thanks for the explanation. I did some tests about 5 or 6 years ago with a scaled up by 10% vintage APS Frankenstein that came up with similar results to yours, albeit they ended abruptly after only 4 or 5 flights & I only kept record of one flight, though it was typical of the rest. Frankie had previously flown with ic power, was later converted to brushed can 480 motor on 7 cell nicads finaly upgraded with a 2200KV BL inrunner with an inefficient 2.3:1 gear box using Etec 2500 3s lipos of around 7C rating. The tests consisted of full power climb out for 60 seconds then stooging around at cruise power for about 15 minutes (with a few mild aerobatics thrown in to break the boredom) then landing, the model had an altimeter on board. The record I did keep : Weight : 35 oz , wing area 430 sq ins, wing loading 11.8 oz/sq ft. Power : 9x4.5 prop; 8.85v, 10.2A, 90Watts, 7500rpm @ WOT. Flight : Max altitude 374 ft in 60 secs, 16 minutes total flight time. Rate of climb 6.3 ft/sec. Battery recharge took 1064mAH. So that's about 41W/Lb @ WOT & average of 5A current during the flight. It would be difficult to estimate the average watts taken as the voltage would have gone up considerably during the cruise phase. The tests ended when the rattley GB fell to bits during the last flight the models been in storage since then. Frankie's overdue a refurb, new motor with decent lipos, probably will be recovered with tissue over doculam as per my Amigo glider, so should lose a few oz as well. Quote Link to comment Share on other sites More sharing options...
Keith Evans 3 Posted October 6, 2018 Share Posted October 6, 2018 Hi David .What did you use to stick the Doculam on with . Keith Quote Link to comment Share on other sites More sharing options...
PatMc Posted October 6, 2018 Share Posted October 6, 2018 Keith, Doculam is heat activated self adhesive film. Quote Link to comment Share on other sites More sharing options...
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