On Saturday 06 December 2008, gerard robin wrote: > On dimanche 07 décembre 2008, gerard robin wrote: > > On samedi 06 décembre 2008, Martin Spott wrote: > > > gerard robin wrote: > > > > With the c172p i have included the following: > > > > > > [...] > > > > > > > To me that is perfect, [...] > > > > > > This is the sole point I'm talking about: Apparently, even > > > though 'we' have "original" drawings of the entire airframe, > > > still none of us has authoritative information at his hands > > > how it is supposed to be properly positioned 'at level'. This > > > is the issue which I'd was trying to sort out. > > > > > > Cheers, > > > Martin. > > > > Yes it is a guess, how many models here are drawn with a guess > > ? not only the landing gear :) > > > > Giving it a pitch of -3 deg is not so bad. > > Or extend more the nose gear which will be ugly. > > AND > The question isn't it , only: > Which is the less stupid :) > to keep the model floating above the ground when not in air ? > or > to modify the offset ? > which won't shock anybody using that FG Reference Model. > > Easy to do, giving the possibility, latter on, to update, if > somebody is able to bring the right blueprint of that Aircraft ( > same model, same equipment .....). > > cheers
Once you've aligned the reference point between the 3d model and the FDM model you should never have to add offsets to the 3d model; if there's a discrepancy it means that something is wrong. The best way, for modellers, is to make the landing gear in it's maximum extended position - the position it would be in without any weight upon it - and use those coordinates for the gear contact points in the FDM. Then you vary the gear spring and compression rates in the FDM so that the aircraft sits on the ground at the right height and attitude, and then finally adjust the model's gear compression animation so that the two match. While it's usually impossible to get exact data on what the height and attitude on the ground should be, with reference to photographs etc. it should be possible to get it correct to within an inch for small aircraft, and perhaps several inches for large aircraft. One of the checks that every modeller should do is to check the gear compression under different loads. This will amount to testing different fuel and passenger loadings, including asymmetric loadings. Military aircraft can also be checked with different weapon loads. Regardless of aircraft type though, once you've got it right the gear will sit on the ground whatever the loading, even with asymmetric loading. LeeE ------------------------------------------------------------------------------ SF.Net email is Sponsored by MIX09, March 18-20, 2009 in Las Vegas, Nevada. The future of the web can't happen without you. Join us at MIX09 to help pave the way to the Next Web now. Learn more and register at http://ad.doubleclick.net/clk;208669438;13503038;i?http://2009.visitmix.com/ _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
