On 22/02/06, Andy Ross <[EMAIL PROTECTED]> wrote: > But the variable speed code will always seek to the specified RPM, and > the current model gives it enough wiggle room to push the torque as > far down as it wants, essentially. You could try setting a > different/tunable "floor" to the pitch value (see the clamping in > Propeller::modPitch()), but getting that value right is going to take > a lot of experimentation.
Since I don't have the time or expertise to do the right thing, I've added a work-around. The values in mod pitch are (loose) representations of the physical stops in a constant speed propeller. For many of the models, the fine-pitch stop allows too small a pitch, thus allowing the propeller to spin too fast at low power settings. I've just checked in some patches to allow aircraft designers to change these values at runtime, using the attributes "fine-stop" and "coarse-stop" to fine-tune the propeller. Currently, these default to the previously hard-coded values of 0.25 and 4.00, so current flight models won't be affected. When I set "fine-stop" to 1.0, for example, the Comanche (pa24-250) idles at a much more realistic RPM, and approach RPM also looks more credible -- I haven't checked in that change until Dave Perry reviews it, though (I'll send him the patch in a private e-mail). The user-visible (i.e. aircraft designer-visible) changes are documented in $FG_ROOT/Docs/README.yasim. Anyone maintaining a YASim flight model with (a) constant-speed propeller(s) should consider playing with these values a bit. All the best, David -- http://www.megginson.com/ ------------------------------------------------------- This SF.Net email is sponsored by xPML, a groundbreaking scripting language that extends applications into web and mobile media. Attend the live webcast and join the prime developer group breaking into this new coding territory! http://sel.as-us.falkag.net/sel?cmd=lnk&kid0944&bid$1720&dat1642 _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
