DFS 230 glider ?

It's been over 2 weeks since I messaged the original modeler, and I have received no reply thus far. Also, he does not appear to have any activity in SOH since 2019. Don't know if he's still around at all. Not sure how to proceed, but I would at least like to do a preliminary test of the flight model in CFS3 by using the ETO Horsa glider as a test bed (swapping in the DFS230 .air file and .cfg file as we previously discussed). Clive, can you talk me through that please? Let me know what lines if any I need to modify? Thanks.

If I find that the flight model works reasonably well in CFS3/ETO then maybe I can go the next step and figure out how to tackle scratch-building a DFS-230 model in Gmax.
 
Hi Mike,

Have you tried posting on the FSX and FS2004 forums to find if anyone knows of his whereabouts?

For the FM you need to modify the cfg as below.

Then copy the dfs230p.air file into the Horsa folder and rename it the same as the Horsa one. Open it with the aired (or similar) proggy and edit the references from the DFS to the Horsa. That should be about it.

CJIXUyn.jpg
 

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Thanks Clive! I'll give it a go and see what happens. I'm assuming I can edit the .cfg file in Notepad. Where can I find the Aired program? Is it in the SDK for building aircraft? I've downloaded that but not yet installed it.
 
Update: I found Aired and was able to make the necessary mods to the .cfg and .air files. The resultant "Horsa-that-flies-like-a-DFS230" works... almost. It flies with all the characteristics of the lighter, more nimble glider, except for the all important bit about landing. I'm putting it down as gently as you can imagine. It gently sinks into the earth to about half the height of the fuselage, and then *Ka-boom* it explodes in a dramatic fireball. I've tried just starting a mission with it sitting on a runway to see what it's natural position and pitch in relation to the ground wants to be, and then tried to copy that in my landings, but it still just wants to blow itself up on landing. (Does not blow up sitting on a runway though.)

Any suggestions would be appreciated.
 
not my area but I imagine it a problem with the contact points in the cfg file

maybe over-write the values under the "[contact_points]" section with the old Horsa values including static pitch, height etc
 
Thanks. I tried swapping back to the original "contact point" info as you suggested. It almost works. The two main wheels make contact with the ground properly now, but when the nose-wheel touches down it (and the nose) just goes through the ground and explodes. What am I missing?
 
If that didnt work then its probably best to paste a copy of the cfg into this thread as Ted said earlier.
 
Trying to help but....

Would love to help but really need to see your contact points to lend a hand. If it sinks, then most likley you are missing a gear contact point or it is miscoded. But without the data, can't really help....
 
Here's the contact points from the cfg files - first the ones from the original Horsa cfg, then the ones from the DFS230 cfg. Let me know if you need to see the full cfgs. I'm sorry for the delay. I'm working on a crazy schedule that only lets me get on here every few days. Thank you for not only your help, but also your patience.

From Horsa cfg:

[contact_points]
//0 Class
//1 Longitudinal Position (feet)
//2 Lateral Position (feet)
//3 Vertical Position (feet)
//4 Impact Damage Threshold (Feet Per Minute)
//5 Brake Map (0=None, 1=Left, 2=Right)
//6 Wheel Radius (feet)
//7 Steer Angle (degrees)
//8 Static Compression (feet) (0 if rigid)
//9 Max/Static Compression Ratio
//10 Damping Ratio (0=Undamped, 1=Critically Damped)
//11 Extension Time (seconds)
//12 Retraction Time (seconds)
//13 Sound Type
//14 Airspeed limit for retraction (KIAS)
//15 Airspeed that gear gets damage at (KIAS)

point.0=1.00,-2.05,0.00,-5.65,2381.108,0.00,1.10,46.80,0.3197,2.50,0.5878,0.00,0.00,0.00
point.1=1.00,-14.33,-4.25,-5.80,2874.804,1.00,2.83,0.00,0.4798,2.50,0.5456,0.00,0.00,2.00
point.2=1.00,-14.33,4.25,-5.80,2874.804,2.00,2.83,0.00,0.4798,2.50,0.5456,0.00,0.00,3.00
point.3=2.00,0.00,0.00,0.00,2100.40,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,4.00,0.00,0.00
point.4=2.00,-14.17,0.00,-1.49,3000.40,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,4.00,0.00,0.00
point.5=2.00,-16.54,-20.71,1.2,787.40,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,5.00,0.00,0.00
point.6=2.00,-16.54,20.71,1.2,787.40,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,6.00,0.00,0.00
point.7=2.00,-32.91,0.00,7.61,787.40,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,9.00,0.00,0.00
point.8=2.00,-32.9,0.00,0.5,2000.40,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,4.00,0.00,0.00
point.9=2.00,-13.54,-13.71,1.2,1000.0,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,5.00,0.00,0.00
point.10=2.00,-13.54,13.71,1.2,1000.0,0.00,0.00,0.00,0.00,0.00,0.00,0.00,0.00,6.00,0.00,0.00

static_pitch =0.98
static_cg_height =4.88

From DFS230 cfg:


[contact_points]
static_pitch = 4.82
static_cg_height = 2.29
tailwheel_lock = 0
max_number_of_points = 9

point.0 = 1, -22.2526, 0, 0.4931, 3200, 0, 0.3, 0, 0.4, 2.5, 0.5, 0, 0, 4, 0, 0
point.1 = 1, -0.2923, -1.8528, -1.9587, 2200, 1, 1.05, 0, 0.5, 2.5, 0.83, 1, 1, 2, 0, 0
point.2 = 1, -0.2973, 1.8171, -1.9587, 2200, 2, 1.05, 0, 0.5, 2.5, 0.83, 1, 1, 3, 0, 0
point.3 = 2, -2.2009, 33.4062, 5.5518, 1200, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0
point.4 = 2, -23.9555, 0, 0.9053, 2400, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0
point.5 = 2, 10.3457, 0, 1.3888, 1200, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0
point.6 = 2, -2.1944, -33.4219, 5.5506, 1200, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0
point.7 = 4, 2.359, -0.586, -0.9119, 2200, 1, 0.6, 0, 0.5, 2.5, 0.83, 2, 2, 4, 0, 0
point.8 = 4, 2.3595, 0.586, -0.9128, 2200, 2, 0.6, 0, 0.5, 2.5, 0.83, 2, 2, 4, 0, 0
gear_system_type=0
 



[contact_points]
static_pitch = 4.82
static_cg_height = 2.29
tailwheel_lock = 0
max_number_of_points = 9

point.0 = 1, -22.2526, 0, 0.4931, 3200, 0, 0.3, 0, 0.4, 2.5, 0.5, 0, 0, 4, 0, 0
point.1 = 1, -0.2923, -1.8528, -1.9587, 2200, 1, 1.05, 0, 0.5, 2.5, 0.83, 1, 1, 2, 0, 0
point.2 = 1, -0.2973, 1.8171, -1.9587, 2200, 2, 1.05, 0, 0.5, 2.5, 0.83, 1, 1, 3, 0, 0

Change the -22.2526 to say -3 and try it. This will move the center wheel up 19 feet and be near the nose. I am not sure that the plane will still balance correctly (not knowing the COG) but its would be a start. If it still fails just try different entries on the first contact point until it works.

point.3 = 2, -2.2009, 33.4062, 5.5518, 1200, 0, 0, 0, 0, 0, 0, 0, 0, 6, 0, 0 Right wing tip
point.4 = 2, -23.9555, 0, 0.9053, 2400, 0, 0, 0, 0, 0, 0, 0, 0, 9, 0, 0 This contact looks like the aft of the glider
point.5 = 2, 10.3457, 0, 1.3888, 1200, 0, 0, 0, 0, 0, 0, 0, 0, 4, 0, 0 This looks like the nose
point.6 = 2, -2.1944, -33.4219, 5.5506, 1200, 0, 0, 0, 0, 0, 0, 0, 0, 5, 0, 0 Left Wing tip
point.7 = 4, 2.359, -0.586, -0.9119, 2200, 1, 0.6, 0, 0.5, 2.5, 0.83, 2, 2, 4, 0, 0
point.8 = 4, 2.3595, 0.586, -0.9128, 2200, 2, 0.6, 0, 0.5, 2.5, 0.83, 2, 2, 4, 0, 0 Not sure about these two but look like contact points just off center left and right of the glider just above the two wheels.

Looks like the glider is about 33 feet long, with a wing span of 66 feet with a COG about 10 feet back from the nose with the wings about 5.5 feet above the horizontal datum line- I found a reference that states 36 and 72 respectively. A little different but close. The Horsa looks like the wings are about 40 feet wide and 16 feet back from the reference line (quite a difference). Looks like the Horsa's nose is the point where all measurements start from since there is a 0,0,0, contact point which I assume is the nose. As I said above the DFS shows a nose 10 feet from the reference line. Not sure this helps but it should give you a better place to start (maybe).
 
Contact points really need a visual tool to work out what is happening, but a couple of observations on the original set (not Ted's rework):–

Points 7 and 8 are float points (type = 4), so don't count in this.

WarGamer describes the glider toppling forward on landing while it will sit comfortably on the runway before flight, so the centre of gravity is quite close to, but behind, the main wheels.

Ignoring the float points, there is only one contact point ahead of the main wheels and that is point 5 which is more than 10 feet ahead of the main wheels and more than 3 feet higher, so the aircraft is going to tip a lot before that hits the ground. Point 5 is also a scrape point (type = 2), not a skid (type = 3), so is looking for possible damage on contact. Finally, the impact speed to cause damage is 1,200 while the main wheels are much higher at 2,200, so the scrape point is more sensitive to the speed at which it hits the ground.

Anyway, that's my thoughts on the problem. The points should be reworked for the final model; if you need a hand with this I'm happy to help.
 
help

Great comments hairspin... if you want I'll take a stab at the model as I have several flight model editors. This really is not a big issue just needs some sorting out...So if you want my help pm me and you can send me the entire model. Have fun.
 
Thanks to Tom and Ted for the insights. I honestly have no clue what I'm looking at in the .cfg files, so every little bit of information you're explaining is a valuable education! Isn't there any sort of tutorial anywhere that breaks down a cfg file and explains what all the numbers mean? That would be a great asset.

To clarify, the 'tipping forward and blowing up' problem occurred after I tried sdsbolt's solution of swapping the original Horsa contact points back into the cfg, not the DFS230 contact points. The DFS230 contact points were the ones that just caused the aircraft to sink into the ground and blow up in the first place. I'm afraid I'm making a muddle of this and not communicating clearly.

Ted, thank you, I'll be sending you a pm asap.

Mike
 
There are documents in the CFS3 Aircraft Vehicle and Building SDK: the one you want is AircraftContainerOverview.doc. There's a lot to get your head around and I won't say all will become immediately clear, but the sdk documents are where to start for explanations. The basic weight/balance/contact points etc haven't changed from before CFS3 right up to FSX and Prepar3D, so any other documentation or tutorials you may find online - and there's lots - will cover the same ground.

By way of example, here's a visual explanation for an FSX aircraft:- https://www.fsdeveloper.com/wiki/index.php/Contact_Points (but be aware that FSX uses a different time scale, twice as long as CFS3)

And we are also here to answer questions!
 
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