FMS 8 Alpha par file HELP

[nmcguff]

I have created several planes for the older version of FMS that work great. I'm in the process of recreating them for Version 8 Alpha.

I have one complete but seem to have a problem. After the plane has landed and comes to a stop the tail of the plane sinks into the ground and sticks the nose up in the air and crashes.

Here is the zip file of the plane.

If anyone has any ideas please let me know.

If you are interested in my other planes visit

These planes are FMS versions of some of the planes found at www.spadtothebone.com and they fly very much like the real R/C aircraft they are modeled after.

[eclipsegsxr]

try changing the center of gravity to :0 0 0
this worked for me but i'm unsure how this thing will fly it seems pretty touchy but by changing the center of gravity to this it stopped the tail from dropping into the ground
let us know if this is a propper fix and that is the way the plane is supposed to handle..

brad

[ggunners]

[nmcguff]

The CG setting was 0 -0.04 0. I changed this to 0 0 0 and it corrected the problem. Thanks for the help. I sure is a lot easier creating planes in FMS 2.0 Beta 7.

I have created 18 planes for FMS Beta 7 and they fly very much like the real R/C planes. The one for FMS Alpha 8 does not fly as well. It will take more time to fine tune the plane to fly correctly. So far I have not seen any improvement between Beta 7 and Alpha 8 except the par file is a lot harder.

I have all the colision and data points correct for the plane but the drag and ploar info tables are a pain to fighre out.

ggunners I have your par8 help files and i'll give the spreadsheet a try. Someone else created the .par file for this plane and I'm trying to get the plane to fly properly.

[eclipsegsxr]

i do know from downloading and trying this plane and checking out the par file that the par file in this plane is hard to read due to all the excess comments that are put in it..try to clean that up and it should help make the par file easier to find the settings you need versus actually reading to find what you need..
know what i mean..

[ggunners]

'm starting to get the impression that the POLAR settings for the surfaces may be extremely important to how the model flies. I'm starting to work on the POLAR settings specifically. I'm seeing that the lift numbers for heavily undercambered wings should be quite high across several degrees with equally high drag parameters. A jet on the other hand should have less lift above a critical angle of attack, but because of swept skinny wings and blended bodies have little drag penalty. I'll be playing around with these numbers and post my results.

-- ggunners

[eclipsegsxr]

can't wait for that info..It should help out alot..did you find anything yet on the plane roll cause of motor torque yet? after scaling down my ARKO plane to a better size. i now notice it wants to dip the left wing as it heads down the runway. but ince in the air it seems to be less noticeable..
i'll let you know what i find as i'm working on what to adjust to solve this problem..

[ggunners]

Well, in order to counter motor torque causing the model to roll, I've gone the route of adding an additional motor turning in the opposite direction. It works, you just have to futz with the motor settings a bit. I now have the Nelson-SU27 flying without torque induced roll. I've also found that by increasing the idle amps, the electric motor will stop free-wheeling and shut down faster. This works great for stopping the motor run on. The only other problem I'm having is too much lift at stall speed when the angle of attack is just slightly above zero. I may have to add an item to the POLAR file for this model.

Here's the dual motor part of the .par file.

MOTOR //Motor(en) (motor, engine)

-0.4415 0 0 //Position [m] (position)
1 0 0 //Zugrichtung (direction of thrust)
0.24 //Propellerdurchmesser [m] (prop diameter)
0.12 //Pitch, Steigung des Propellers [m] (prop pitch)
2 //Anzahl Propellerblätter (number of prop blades)
0.02 //mittlere Propellerblatttiefe [m] (mean chord prop blades)
RIGHT //rechtsdrehender Propeller (prop rotation)
0.0002 //Rotationsträgheitsmoment von Propeller und Motor [kg*m^2] (rotation moment of inertia)
4 //Kanal (channel 4)
ELECTRO //Motortyp = Verbrennungsmotor (motor type)
7.4 //Nennspannung des Motors [V] (motor voltage)
12000 //Leerlaufdrehzahl [U] (idling speed)
15 //Leerlaufstrom [A] (idling current)
70 //Blockierstrom [A] (blocking current)
1 //Ãœbersetzung des Getriebes (typischerweise > 1) [-] (translation of transmission, typical > 1)
1 //Getriebewirkungsgrad [-] (transmission efficiency)
9 //Anzahl Zellen des Akkus (number of batt cells @ 1.2v)
1200 //Kapazität des Akkus (0=Akku nie leer) [mAh]
5 //Innenwiderstand des Akkus [mOhm] (internal battery resistance)

Second MOTOR is exactly the same except with

LEFT //rechtsdrehender Propeller (prop rotation)

-- ggunners

[Scott Crownover]

Norman,

Great work on those virtual SPADs. Keep em comming. I hope you get a version of the SPAD3D or QHOR running in Alpha 8.1.

SC