Newbie Requires Assistance with FSD3 (please)

[MikePotten]

Thank you for taking the time to read my post.
I've been fltsimming since FS2 so well experienced with FS but new to the Design World. Prepared to learn like everybody and not just post loads of questions, so going through the Tutorials and trying to learn myself but there is one bit I can't understand as follows. In the intermediate exercises I've created my first aircraft and if I say so myself she looks great for a first attempt but for the life of me I can't get her sitting on her wheels in FS9 even though I've placed the bottom of the wheels firmly on the X- Axis as per the other lesson with the Stop sign, so the X Axis line in FSD 'appears' to be in the wrong place. I've got my aircraft sitting on the ground now but trial and error i.e. keep saving the project at different heights until it sits right but the X Axis line marker is way above the wheels in FSD, even then though with the curser held on the X Axis datum line the pointer at the bottom of the screen shows it to be -0.033ft, to get my aircraft sitting on the ground correctly the bottom of the wheels had to be moved down even further to -3.722ft. So I can't go by the X Axis datum line in FSDS and my wheels are apparently 3.722 ft 'underground' in flight sim but looking good in flight sim. I have FSDS set to ft and Flightsim set to ft so I don't think it's a conversion problem.

Any assistance would be truly appreciated.

Thanks in advance.

[Au_Wozza]

Hi
The problem relates to compression ratio ect in the aircraft.cfg and animation length in fsds3
There is a great tut here http://www.sim-outhouse.com/sohforum...ad.php?t=13564

cheers
Wozza

[andyjohnston]

The axis line should go through the centre of your plane, that's the line it will rotate around. What you need to do is adjust the contact points in the aircraft.cfg file, which define where the sim considers the wheels to be.

You should use the line as your bottom for scenery objects, but not for aircraft.

[MikePotten]

Thanks Andy/Wozza, much appreciated.

Have taken a quite look at the link you provided on compression Wozza but obviously needs some study so will review carefully later today.

Andy, I placed the X Axis close to the middle of the model in FSD and it was more or less spot on, so you are, of course, correct. It doesn't seem to make sense though that they've designed it like this i.e. I assume that if you design an aircraft with very long u/c legs (I can only think of the Fiesler Storch or the prototype Jet Provost) and you place the datum line in the middle of the fues then I assume that the wheels would be under ground. It made sence when I did the tutorial on the sign i.e. it stated that you need to place the bottom of the sign on the datum line as this is ground a zero in flightsim, so doesn't make sense if this applied to scenery only but obviously that's what they've done. Anyway, if that's the way it is then that's the way it is.

I have two other questions if I may:

How do I stop the nosewheel dipping under the runway under braking?

Having looked at the contact points earlier to resolve the main problem is there a note on what each value relates to so I know how and what to change or is it down to good old trial and error again?

Thanks again guys for your assistance, much appreciated and Seasons Greetings to you!

[andyjohnston]

Umm, off the top of my head, the first value is forwards and backwards, I think the second is left and right and the third is up and down, but I may have 2 and 3 reversed. Then just follow what's in the cfg to figure out what the others do. The contact points define how high above the ground your plane will sit, or to be more presice, how far below the centre line the wheels hang.

As for the centre line, think of it as the most important point. For a scenery object, the most important point is where does it touch the ground. For a plane, where does it rotate. If a plane had no contact points defined, it would also sit along that line (half buried in the ground of course.) It works the same way in GMAX.

[MikePotten]

Andy, thanks for that, appreciated.

The way you've put it now makes complete sense i.e. it's 'how far the wheels extend below the X datum line, that makes sense. Also what we are saying then, in aerodynamic speak, is that scenery objects have to sit on the X Axis but aircraft have to be setup around the C of G then. That being the case I would imagine that the placing of the Y Axis is also critical for correct rotation on take-off and landing etc. I'll play around with the Y axis moving it forwards and backwards and see what happens.

Thanks for the info on the contact points, I'll have a play with those too.

Really appreciate the time you've taken with me. I want to get to grips with this for myself but also so I can put something back in to the hobby having been flying other peoples freeware for many many years. I started doing re-paints a short while back so this is the next obvious step and I have some aircraft I'd like to be able to fly but nobody else has done them. Should you wish to see if any of my repaints are of interest to you just do a search under 'potten' on fltsim.com.

Many thanks once again for your time Andy and Seasons Greetings to you.

Kind regards