Former Member Posted February 8, 2009 Share Posted February 8, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 8, 2009 Author Share Posted February 8, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 8, 2009 Author Share Posted February 8, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 8, 2009 Share Posted February 8, 2009 Ok measured all of mine.....they are all correct and agree entirely with both Eric's system and the online one too PS - remember the way to the Orme ?? Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 9, 2009 Author Share Posted February 9, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 9, 2009 Author Share Posted February 9, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Bruce Richards Posted February 9, 2009 Share Posted February 9, 2009 On my Greatplanes Slinger the calculator (at 25%) puts the CofG too far forward at 160mm. Eric's method puts it at 205mm which is where have mine.. I must admit that some of the dimensions for the calculator are difficult to get since the elevons on the slinger do not go right to the root. However, trying a range of different values I can't get the calculator to give a value anywhere near my CofG. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 9, 2009 Share Posted February 9, 2009 1st question... I have never tried it so cant honestly say - besides, I presume you are talking brushed ESCs and these are now so rare you would be better off flogging them on the antiques roadshow to fund the purchase of a proper regulator 2nd question, did you REALLY think I had done that - in 8 minutes - at close to midnight ? stupid boy.... LOL Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 9, 2009 Author Share Posted February 9, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 9, 2009 Share Posted February 9, 2009 Hee hee. Ah, I think you now are saying that you intend to use the BEC circuit of the ESC to power things ? You didnt say that before, and I assumed you meant use the ESC itself. Stupid stupid boy - back on the naughty step! If indeed you do mean to utilize the BEC, then this is usually a seperate circuit altogether from the actual ESC controller, and not connecting the ESC output to a load should not matter. Expensive regulator though Phil Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 9, 2009 Author Share Posted February 9, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted February 9, 2009 Share Posted February 9, 2009 How about starting with it at the point suggested by Eric's method - this brings twofold benefits 1) its more likely to be correct from what Bruce was saying 2) I know where Eric and Bruce live ...so if its wrong its not far for the heavies to travel Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 9, 2009 Author Share Posted February 9, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 10, 2009 Author Share Posted February 10, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted February 10, 2009 Author Share Posted February 10, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Clark Ross Posted September 3, 2009 Share Posted September 3, 2009 the trouble i have with a wing is when i use a twist in the wing i don't know what angle difference there should be between the root and the tip. not enough and it will tuck under to much and you are just adding drag. i agree with the one third of the mean chord projected back to the root chord but the location of the cg seems to be effected by the twist or angle of the elevons. does anyone have an idea what the angle should be. Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 3, 2009 Share Posted September 3, 2009 I think what you are referring to is washout and not all wings have this. Quote Link to comment Share on other sites More sharing options...
Clark Ross Posted September 3, 2009 Share Posted September 3, 2009 no tim all flying wings have either a twist in the wing or elevons that have a little up in them or like a plank which has a reflexed airfoil. on a swept wing you have to have a different angle at the tip because the wingtip becomes the stabilizer and just like a normal airplane there has to be a difference between the wing and stabilizer .of course the twist also acts as washout to prevent tip stall. a good web site for flying wings is( the wing is the thing) regards clark Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 3, 2009 Author Share Posted September 3, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Martin Harris - Moderator Posted September 3, 2009 Share Posted September 3, 2009 OK , Polyphilla, you asked for it! in simple terms, when a bank occurs, the model slips toward the lower wing and the airflow over the lower wing is presented at closer to right angles to the leading edge than that of the higher wing. In addition, any fuselage causes a blanking effect on the top wing. The net effect is that the lower wing produces more lift, hence a stabilising effect and the reason that anhedral is not uncommon on swept wings to reduce the inherent stability. Extra induced drag will be produced as a consequence of producing extra lift contributing to any tendency towards Dutch rolling but the roll stability is due to the difference in lift produced by the slip. Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 3, 2009 Author Share Posted September 3, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 3, 2009 Author Share Posted September 3, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Tim Mackey Posted September 3, 2009 Share Posted September 3, 2009 Far too much worrying about all this higly techincal stuff, and not enough foam cutting !Oops, off topic - someone moderate me Quote Link to comment Share on other sites More sharing options...
Former Member Posted September 4, 2009 Author Share Posted September 4, 2009 [This posting has been removed] Quote Link to comment Share on other sites More sharing options...
Erfolg Posted September 4, 2009 Share Posted September 4, 2009 I have used the calculator on my flying wing. It certainly produces results which are safe and usable. The most rearward CG is 12mm in front of the method, which I personally used. My method produced a CG where the model, could spin at any time, anything unusual occured. My method required a little bit of maths and measuring, carefully. So I endorse the calculator as being "Simple" and "Fast". My wing is a higher aspect ratio than appears to be currently popular as in Zaggis and some other slope jobs, being, if memory serves me well10:1. Erfolg Quote Link to comment Share on other sites More sharing options...
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