bees Posted July 1, 2020 Share Posted July 1, 2020 Mine also has a 13x6 prop and motor from 4-max. In all my years model flying i have never experience anything like this. I have a 3d fokker that will not turn by ailerons alone, rudder is the only wait will turn. At first i thought i had no signal but managed to land but it did the same on the second flight again no control regarding right input but plenty of left turn. Quote Link to comment Share on other sites More sharing options...
bees Posted July 1, 2020 Share Posted July 1, 2020 Forgot to mention, i had already added some slight down thrust and right thrust before the first flight. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 2, 2020 Author Share Posted July 2, 2020 Most peculiar!!! So far no one else has had this problem and I do not have any side or down thrust on my model. Quote Link to comment Share on other sites More sharing options...
Tim C Posted July 14, 2020 Share Posted July 14, 2020 Video clip of maiden attempt https://youtu.be/1bk0-QapgOU not a success, took off then abrupt turn left and no effective roll control, Even with rudder. 2nd flight hairy after some fiddling with aileron settings, no damage, assessing options as to what next Edited By Tim C on 14/07/2020 18:19:59 Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 14, 2020 Author Share Posted July 14, 2020 I can't get the video to work. Quote Link to comment Share on other sites More sharing options...
Tim C Posted July 14, 2020 Share Posted July 14, 2020 Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 14, 2020 Author Share Posted July 14, 2020 THat looks as if the CG is far to far back/ Just where is the balamce point? Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted July 14, 2020 Share Posted July 14, 2020 i reckon the c of g needs to go forward...weight in the nose reqd.. ken anderson...ne...1...c of g dept. Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 14, 2020 Author Share Posted July 14, 2020 Move the balance point (CG ) forward to 25% wing chord. IT is forward of the one shown on the plan but will stabilise the model. Quote Link to comment Share on other sites More sharing options...
Tim C Posted July 14, 2020 Share Posted July 14, 2020 I tend to agree, the cg set on the Rcme plan mark which is fwd of that on Peters hand drafted plan, I have added some nose weight about 55gm, but have yet to put the wings on to check on the cg balancer. I have also checked for any trimming issues which give a left bias, as was unable to check any trimming on the test flights Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted July 14, 2020 Share Posted July 14, 2020 Mine is 62mm from the wing LE and that is without a tank of fuel. Had a quite normal flight with it on Sun. and landed with 1/2 flap. Really just to check out the motor idle which I have had problems with. Quote Link to comment Share on other sites More sharing options...
DaveyP Posted July 14, 2020 Share Posted July 14, 2020 @Timc would I be right in thinking that was Strawberry fields ? Quote Link to comment Share on other sites More sharing options...
Tim C Posted July 14, 2020 Share Posted July 14, 2020 Yes Strawberry field Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 14, 2020 Author Share Posted July 14, 2020 If the CG is too far back (as it certainly looks) then control authority will be very much less and the model will tend to wallow about.Tis will make any very slight warps affect the flight more. AS the old saying goes. If the CG is too far forward the model will fly badly. If it is too far back it will fly once! Quote Link to comment Share on other sites More sharing options...
Tim C Posted July 15, 2020 Share Posted July 15, 2020 I have checked the cg, it was on 65mm from front of LE, the black x, now moved about 8mm fwd , the pencil mark. one wonders if the chord is measured from the front of the slat or the le. If you include the slat, the chord is 260mm, 25% would give 65mm from the front of the slat? Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 15, 2020 Author Share Posted July 15, 2020 Interesting. My CG is 65mm from the leading edge of the wing. Moving yours forward 8 mm should make it better because that video really looked as if it was tail heavy. Quote Link to comment Share on other sites More sharing options...
Tim C Posted July 17, 2020 Share Posted July 17, 2020 Success today, moved the CG fwd about 8mm and added a bit of right bias in the trim and side thrust and 20% rudder to aileron. Probably overdid this as it required left trim! All very sedate scale like and steady. Landing at a snails pace. Some fine tuning on the trims will help and some more cooling slots to the motor, the added lead is blocking the cooling exit, all in all well pleased, had a total of three flights. YouTube Quote Link to comment Share on other sites More sharing options...
ken anderson. Posted July 17, 2020 Share Posted July 17, 2020 well done Tim, looks like a different model, flying in the video.....sure it's not some one else's?... ken anderson...ne..1..success dept. Quote Link to comment Share on other sites More sharing options...
Trevor Posted July 17, 2020 Share Posted July 17, 2020 Congratulations Tim! Persistence was rewarded! Trevor Quote Link to comment Share on other sites More sharing options...
Peter Miller Posted July 17, 2020 Author Share Posted July 17, 2020 Well done!! IT is interesting how a slight change can make so much difference. Have fun now Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted July 17, 2020 Share Posted July 17, 2020 Glad that you got it right in the end. Practice with the flaps at height. Quote Link to comment Share on other sites More sharing options...
Geoff S Posted August 22, 2020 Share Posted August 22, 2020 I've just ordered the CNC parts from SLEC and building will commence shortly (I've hot to drag myself out of lethargy somehow! ). I've been studying the drawing and article in the magazine as well as the PDF files Peter so kindly sent me and one thing ín particular puzzles me - why are the flap servos installed as mirror images thus needing a reversing Y lead to connect them to a single receiver channel? Is there any reason why I can't have the servos oriented the same on both wings (ie with the arm pointing (say) port) rather than with them both pointing inwards? It seems to be a common issue. My Multiplex Fun Cub is the same and I've connected the flap servos to separate receiver channels. As I had a spare channel anyway it wasn't a problem but it seems odd to me. Geoff Quote Link to comment Share on other sites More sharing options...
Trevor Posted August 22, 2020 Share Posted August 22, 2020 As long as you’re not planning on any aileron/flap mixing, there’s no reason not to flip one of the flap servos and use a Y lead. If you’ve got a spare channel to spare though, it can make setup a bit easier, especially if the servo splines prevent precise alignment of the servo arms. Quote Link to comment Share on other sites More sharing options...
Tim C Posted August 22, 2020 Share Posted August 22, 2020 I flipped one of the flap servos and used a Y lead on mine, endorse the issue with funcub which either needs another channel or a servo reverser, my P2000 glider is at least designed to use flipped servos on the flaps Edited By Tim C on 22/08/2020 15:25:15 Quote Link to comment Share on other sites More sharing options...
Martin McIntosh Posted August 22, 2020 Share Posted August 22, 2020 Very much easier to use two channels on flaps if you can. Ditto ailerons. Quote Link to comment Share on other sites More sharing options...
Recommended Posts
Join the conversation
You can post now and register later. If you have an account, sign in now to post with your account.
Note: Your post will require moderator approval before it will be visible.