John Timmis Posted November 14, 2014 Author Share Posted November 14, 2014 Hi folks, I've not posted for a couple of weeks. It's not that I've done nothing but rather that there isn't much to show for it. Everything seems to take twice as long on this model. Before the rudder hinges could be glued the fuselage tail fairing had to be made, fixed in place & covered. That took a while. Then a number of small things to finish off. The CG has been checked, batttery bay finished , servos connected & radio installed. Although still far from finished it is completed to a state where it can be test flown. Just waiting for a suitable day & we can have the first fright. According to my kitchen scales the AUW is 7ld 8oz. Does that sound reasonable? Since I returned to rc about 6yrs ago Ihave only flown elecric models. This is the largest & heaviest so far. Also the first with flaps. Any advice re flaps would be welcome, they are on a switch & are either up or down. Cheers John. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted November 14, 2014 Share Posted November 14, 2014 Hi John, I would suggest you try the flaps at considerable altitude to see what effect they have? My big Chippy I have moved the flaps to one of the sliders, so I can select an infinite setting but there is an indent at half flap. On this DB one I will set the indent at 15 degrees and 30 degrees full flap. I think those were the numbers in the pilots notes Often full size Chippys seem to take off with the "short field" flap setting of 15 degrees. Not easy to simulate with an all or nothing Looking forward to seeing how yours goes, what cells/power are you getting? Cheers Danny Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted November 14, 2014 Share Posted November 14, 2014 Looks very good John the tail fairing looks spot on weight ? I have no idea, but 71/2 sounds o.k to me. Good luck with the maiden John Quote Link to comment Share on other sites More sharing options...
John Timmis Posted November 18, 2014 Author Share Posted November 18, 2014 Hi folks, This is where we are today. Obviously there is still lots that needs to be done but it's in a state where it can be test flown. A few facts & figures before the first fright. The weight has finished up at 7lb 8oz. The build, as far as I can remember because most of it was done years ago, is just as drawn on the plan. I probably changed the undercarriage fixing but no extra washout was built in. The elecric conversion has clearly increased the weight compared to the original Merco 61. However, the cg is spot on with no extra ballast. Servos are all standard size Futaba. The power train components I bought at the Cosford show. The intention was to buy something similar to what was suggested in Danny's earlier post. In the event, having been advised that nobody ever asked for 5s batteries these days, I bought a 6s , 4500 mAh , 30C Dynamic battery. To go with this there was a 70amp speed controller & a 650kv motor rated at 1150w. Also a 14x7 prop. This is clearely much more than is needed but there is always the throttle stick. Having just run this setup through the watt meter, I saw 1.5 kw at full throttle. HELP. I'm at the bottom of the learning curve regarding larger electric models. Any suggestions please. Cheers John. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted November 18, 2014 Share Posted November 18, 2014 Wow John, awesome power The cell count in my opinion could come way down, 4S on a 620kV would be about right. But if you want to go with what you have just take a couple of inches off the prop, try an 11 or 12 x 8 something like that, just to prove all is well? Looks great, really looking forward to seeing how it goes Cheers Danny Quote Link to comment Share on other sites More sharing options...
Chris Bott - Moderator Posted November 18, 2014 Share Posted November 18, 2014 Looks great John, good luck Whoever advised that nobody asks for 5S batteries just had none in stock, is my guess. I think we'll end up using 5S with those Kv's and a 14" prop. 4S might well be fine though. As Danny says, to use a 6S, keep testing with smaller props until your measured watts are lower than the motor's spec. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted November 18, 2014 Author Share Posted November 18, 2014 Danny, Chris, Thanks for that, I'll give it a try. I also have some 4s 3200 mAh batteries I could try. Depends how they fit & the cg. Cheers John Quote Link to comment Share on other sites More sharing options...
Andy Muckley Posted November 18, 2014 Share Posted November 18, 2014 Good luck with the test fright John and will be nice to know if washout is needed, too late for me as wing is built as per plan, will be eagerly waiting on your report and good luck again John Quote Link to comment Share on other sites More sharing options...
John Timmis Posted November 28, 2014 Author Share Posted November 28, 2014 Hi folks, Well, changing the prop to a 12x6 has reduced the watts to a more reasonable figure. Last Sat the weather was perfect for a first flight, batteries all charged, so all set for a 'Will it or won't it moment?'. What could possibly go wrong? So everything set to go, all psyched up, do a range check.................. NO AILERONS. The plug on the new aileron servo had disintegrated. Ahhhhhhhhhhh Don't know if it was crushed when the wing was put on..... can't think of anything else. Anyway fingers crossed for tomorrow. Cheers John Quote Link to comment Share on other sites More sharing options...
Nev Posted November 28, 2014 Share Posted November 28, 2014 Hi. I was wondering what had happened last weekend, we were all waiting in anticipation. Shame about the plug but at least you found out on the ground. Hope the weather is kind tomorrow. Nev. Quote Link to comment Share on other sites More sharing options...
Terry Walters Posted November 29, 2014 Share Posted November 29, 2014 Best of luck John! Terry Quote Link to comment Share on other sites More sharing options...
John Timmis Posted November 29, 2014 Author Share Posted November 29, 2014 Hi folks, The chippie had its first flight this morning. Thanks for the good wishes. There was no drama at all. The weather was pretty grey, low cloud & poor viz. At least it wasn't too windy & no rain. Typical Nov really. The aim of this flight was quite simple: To prove it would fly, get it trimmed, try the flaps & get down in one piece, The motor is rated at 1150 watts & a 12x6 prop had brought the power down to just under this figure. No shortage of power then. Checks complete. Take off & climb out is brisk as expected. Throttle back to a reasonable speed & it's flying hands off already, not even a click of trim. Next try some shallow turns & then some steep turns. It all feels very solid. No nasty tendencies, responsive yet stable & quite docile. In fact very well mannered indeed. Next, gain some height & try the flaps. OK throttle down, flaps down. No detectable change in attitude, still flies hands off. Great. Keep the flaps down. Loose some height & into the circuit. Don't touch the flaps again. A bit more throttle to control the sink, round out & we are down in one piece. Brilliant. Only 5 min, can't wait to do it again & explore some more. The battery had 78% charge remaining. In the air, it will slow down nicely. I thought it really looked the part & fllew the way a chippie should fly. Keep at it chaps. You're in for a treat. Cheers John. Quote Link to comment Share on other sites More sharing options...
Danny Fenton Posted November 29, 2014 Share Posted November 29, 2014 Brilliant news CheersDanny Quote Link to comment Share on other sites More sharing options...
john stones 1 - Moderator Posted November 29, 2014 Share Posted November 29, 2014 Result John well done John Quote Link to comment Share on other sites More sharing options...
Terry Walters Posted November 29, 2014 Share Posted November 29, 2014 Hi John - great news well done. Looks like there's hope then! . Terry Quote Link to comment Share on other sites More sharing options...
Nev Posted November 29, 2014 Share Posted November 29, 2014 Well done John, sounds like a perfect first flight. looks good on the ground, bet it looked better in the air. Nev. Quote Link to comment Share on other sites More sharing options...
Nigel Day Posted November 30, 2014 Share Posted November 30, 2014 Nice one John. Quote Link to comment Share on other sites More sharing options...
Charles Galloway Posted November 30, 2014 Share Posted November 30, 2014 Well done bodes well for the rest of us. Quote Link to comment Share on other sites More sharing options...
Andy Muckley Posted November 30, 2014 Share Posted November 30, 2014 Well Done John good feeling when it all goes well ain't it Quote Link to comment Share on other sites More sharing options...
Andrew Price 2 Posted November 30, 2014 Share Posted November 30, 2014 Very well done John. Quote Link to comment Share on other sites More sharing options...
Colin Leighfield Posted November 30, 2014 Share Posted November 30, 2014 "There was no drama at all". The words I love to hear! Hope I will be able to do the same, good one John! Quote Link to comment Share on other sites More sharing options...
John Timmis Posted December 1, 2014 Author Share Posted December 1, 2014 Thanks everone for the comments & encouragement . We did manage to get a few photos in the air but its not easy to shoot a silver plane against a grey sky, particularly when I'm trying to fly at least 3 mistakes high. Will try again on a better day. Meanwhile, I shall add a few simple details & finish off the paint scheme. It's only intended to be a ' stand 10' away & squint job' so it won't take too long. Then I can start catching up with the rest of you with building the next one. Onwards & upwards. Cheers John. Quote Link to comment Share on other sites More sharing options...
John Timmis Posted December 6, 2014 Author Share Posted December 6, 2014 Hi folks Flew the Chippie again this morning. Had 5 or 6 flights now. The handling continues to be very benign. It will do enormous loops. The only problem has been that it always ends up on its nose at the end of the landing. It could be the rather long wet grass. It's not easy to get good photos in the air but these are the best so far. Still some more details to add but it's getting there. Cheers John. Quote Link to comment Share on other sites More sharing options...
Nigel Day Posted December 6, 2014 Share Posted December 6, 2014 Looks great John. Quote Link to comment Share on other sites More sharing options...
Andy Muckley Posted December 6, 2014 Share Posted December 6, 2014 Cheer's John thank's for the pic's , looks like it sit's nice in the air Quote Link to comment Share on other sites More sharing options...
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