Back in the 60´s and 70´s we found that bungee rubber gave better feel than steel springs when we made simple (i.e. non-hydraulic) feel units from time to time for our research simulator.
I also built a few hydraulic systems, but these need lots of safety devices to protect the pilot from run-aways. I was contemplating building a unit based upon direct drive from large dc torque motors driven by power amplifiers, but never got past the preliminary design. We did however use direct electric motors for throttle servos and trim wheels. They cut out if the motor current went too high due to pilot override. Alan -------------------------------------------------- From: "Harry Campigli" <harryc...@gmail.com> Sent: Tuesday, March 23, 2010 5:33 AM To: "FlightGear developers discussions" <flightgear-devel@lists.sourceforge.net> Subject: Re: [Flightgear-devel] Elevator control loading > John, > > I cant help with your software question, but I also am working on > control loadings for rudders, and yokes in a dual pilot jet setup. > > Currently I have completed the rudder setup and working on the yokes. > Ailerons for now, elevators next. > > i will interface them to FG but using a pic as the controller. > > I have made a device similar to a Boeng feel unit but no hydraulics, > ie, a vee made of 2 arcs with a bearing running along it as a cam. one > spring is set up for minimal centering pressure, a motor positioned > second spring is added over the first spring under computer control to > increase the control loading. > > Then the entire unit is rotated bt a second motor to move the centre > point, and or, force the sim pilot to apply a certain amount of force > on the control to maintain the desired attitude. I was planning load > cells in the control linkage but think i will get by with measuring > the force at different angles and putting in a software lookup table > This same motor will also position the controls in autopilot mode > (pilot hands off) > > I am using a linear actuator made from a wiper motor on the spring and > an 18 inch satellite positioning actuator to move the unit. > > Possibly its better and easier with a big servo motor setup but while > i have seen many posts in sim builder forums about testing different > types of motor, I have not seen an example of a motor that really fits > the bill. > > Possibly we can compare notes on a separate email as this hardware > rather than FG code? > > Harry > > > > > > > > > > On Tue, Mar 23, 2010 at 1:03 AM, <cas...@mminternet.com> wrote: >> Hi, >> >> Can anyone shed some light on the following question? >> >> Does JSBSim calculate elevator position and control hinge moments based >> on >> the general equation of motion, including inertial coupling, is described >> by Etkin( 1982 ), or do the FDMs simple accept the value provided via FG >> or a network interface and position the elevator at that value analogous >> to an irreversible control system. >> >> Working on a control loading system and before digging into the JSBSim >> code, thought I might ask the question of save some time. >> >> Thanks >> John >> >> >> >> ------------------------------------------------------------------------------ >> Download Intel® Parallel Studio Eval >> Try the new software tools for yourself. Speed compiling, find bugs >> proactively, and fine-tune applications for parallel performance. >> See why Intel Parallel Studio got high marks during beta. >> http://p.sf.net/sfu/intel-sw-dev >> _______________________________________________ >> Flightgear-devel mailing list >> Flightgear-devel@lists.sourceforge.net >> https://lists.sourceforge.net/lists/listinfo/flightgear-devel >> > > > > -- > Regards Harry > > 19b Jln Danau Poso > Sanur, Bali > 80228 > > H +62 361 285629 > M +62 812 7016328 > > ------------------------------------------------------------------------------ > Download Intel® Parallel Studio Eval > Try the new software tools for yourself. Speed compiling, find bugs > proactively, and fine-tune applications for parallel performance. > See why Intel Parallel Studio got high marks during beta. > http://p.sf.net/sfu/intel-sw-dev > _______________________________________________ > Flightgear-devel mailing list > Flightgear-devel@lists.sourceforge.net > https://lists.sourceforge.net/lists/listinfo/flightgear-devel ------------------------------------------------------------------------------ Download Intel® Parallel Studio Eval Try the new software tools for yourself. Speed compiling, find bugs proactively, and fine-tune applications for parallel performance. See why Intel Parallel Studio got high marks during beta. http://p.sf.net/sfu/intel-sw-dev _______________________________________________ Flightgear-devel mailing list Flightgear-devel@lists.sourceforge.net https://lists.sourceforge.net/lists/listinfo/flightgear-devel
