my DC-8 Project

[Mr.FaosFX]

DC8 development resumes for the weekend...

Well the 11 hours aren't really that bad, as I have reached the end of the work week but I do not feel tired, sleepy but not tired, as my job is pretty simple. In case anyone is interested, I'm an Amazon.com ABE2 Outbound Picker ... I just walk around all day with a little cart and a scanner and I pick products, that's it, lol ... the hard part of the job is I walk at least 13 miles a day. I have to pick products at a rate of 125/hr you could probably already imagine, I have to almost speed walk to make the rate but time goes by really fast because you are so focused on getting to the next bin to pick the next product, it's a fun and challenging job.

Anyway, after arriving from work the last few days, I have been actually working on the DC8 investing at least 1 hour before I go to bed and just now I finished a good amount of work, enough to merit a little update.

Thanks to Ztimbre :-] note the new head light support assembly! This is as close as I could get it and it looks pretty good, I love it and had tons of fun making it, stuff that people will not notice or care about but you know what, I had fun making it and that's what counts for me and it makes the model all that creative and, with this inspiration to not hold back on adding detail, you'll also notice on the right, I actually put in the spring, lol! I'll leave it there as my signature to this model, the little fella is 975 polygons but I don't care, it looks cool and I like it and I had fun with it, that's all that counts :-] I'm putting all my love into this plane!

I will continue work on the DC8 today when I wake up again, maybe at around 4 pm I think, that's about 8 hours from now and then I have plenty of time so I guess, I will not be that inactive during the peak season, good news!

More to come later, stay tuned guys, now off to bed I go.

ZZzzZZZ....

 

[Mr.FaosFX]

Finishing up with the swivel hinges as I type this in...only a minor issue at the moment. I'll have a shot of the completed hinges soon, they are nothing fancy but its progress, sorry no pics for now.

 

[Mr.FaosFX]

Update!

I just got done with the door hinges, it was more time consuming than I anticipated, modeling really small parts really takes a long time.

Just three final details remaining to be added, swivel connectors for the nose gear doors [front and back]; the ones that pull them up and down and after that is done, the nose gear tires and then the nose gear is pretty much completed at that point, it would appear I did a better job with the nose gears than I did with the landing gears, I may actually go back and redo parts of the main landing gear when I get around to that.

Once I add the finishing touches to the nose gear, I shall begin linking the parts and then, time to animate them, I do not plan to texture it now.

I will be returning to the tail section once the nose gear work is done to add some other details then begin fine tuning the current model before I do any more work on it.

I was up all night or should I say morning? Anyway, going to bed now, later guys.

Hope you liked the pic!

 

[Tejal Bernardo]

Hi Faosx, the Dc 8 is progressing, and I hope you survive the Chistmas time

 

[Mr.FaosFX]

Hi Faosx, the Dc 8 is progressing, and I hope you survive the Chistmas time

Thanks Tejal

 

[Mr.FaosFX]

Doing some research before linking and animating parts now, animation of the nose gear is nearly underway. A couple of things I've learned. The rear doors on the nose gear are not actuated by a hydraulic cylinder! They are connected to the upper shaft side braces and linked by brackets that swivel and pull the doors in as the gear retracts.

The front doors open and then the gear starts coming down, as the gear comes down the rear aft doors slowly open as the brackets push them down while the door swivels on its pivots, interesting in deed!

I always thought the rear doors would open first but they don't! That would be impossible the way they are setup to operate on the DC8, the front doors open first and then the rear aft doors slowly open as the gear comes down. During retraction of the gear, the rear aft door slowly closes until the gear is fully up, then the front doors close.

Keep tuned for updates.

 

[hairyspin]

Good stuff, realistic gear animations are always worthwhile!

 

[Mr.FaosFX]

Good stuff, realistic gear animations are always worthwhile!

I did the main steering gear animation with c_wheel and it works fine, tires go left and right as they should. However, linking it to the cylinder rods that extend when the steering axle moves, that looked so crazy when I linked it to c_wheel, so I believe I will have to take the XML route here, I just need to find WHAT to monitor to know when the wheels go left and right.

I tried another technique by calling several parts c_wheel, the same name but only 1 c_wheel in particular responds when steering occurs. You can create multiple parts called rudder and they all rotate at the same time but with c_wheel this is not the case, I thought I could get away with that, lol.

It's been a while since I've messed with animations like these and I did make articulating cylinder rods for one of my fantasy planes, I did use XML but I just don't remember how I even did it, it's been a while =/ And I lost all those planes.

 

[Mr.FaosFX]

-<part>
    <name>rudder_key</name>
         -<animation>
             -<parameter>
                 -<sim>
                      <variable>RUDDER DEFLECTION</variable>
                      <units>grads</units>
                      <bias>50</bias>
                 </sim>
              </parameter>
         </animation>
 </part>

Here is a little something I extracted from MakeMDL.parts.xml this is the XML code used to animate a custom rudder...I actually use this particular animation on the DC8 already pre-defined in MakeMDL.parts.xml I know that bias is the offset of the animation and I pretty much know the format of the animation code what I am looking for now is a different variable other than RUDDER DEFLECTION why? Well because HJG has the original aircraft configured so that the rudder is inoperable unless the aircraft is traveling a certain speed, so I have to find another way to implement my articulating cylinders and it has to do something with the nose gears.

I am posting it here so hopefully somebody beats me to that variable and I can use it for testing purposes before I implement it.

This is where the fun begins!

 

[Mr.FaosFX]

Ha ha I've got it! Rudder pedals! Sweet!

 

[Mr.FaosFX]

Update!

Well you can't forget what you learn, I remembered how I did it, it was monitoring the rudder pedal positions. I got the animation work done and it works quite well :-]

Since I cannot show a preview of this in pictures, I created a video and uploaded to my youtube channel.

Click this link >>> http://www.youtube.com/watch?v=BHbuQa87C5I to watch video of the DC8 nose gear steering + articulating hydraulic steering rods, really neat stuff.

If anyone is interested in knowing how I did it, here is the XML code that makes it work...

* The part names are pretty self-explanatory but you can guess which is which by watching the video closely.

<part>

<name>c_gear_steering_axle</name>

<animation>

<parameter>

<sim>

<variable>RUDDER PEDAL POSITION</variable>
<units>part</units>
<scale>50</scale>
<bias>50</bias>​

</sim>​

</parameter>​

</animation>​

</part>

<part>

<name>c_gear_left_steer_cylinder</name>
<copy>c_gear_steering_axle</copy>​

</part>

<part>

<name>c_gear_left_rod_connector</name>
<copy>c_gear_steering_axle</copy>​

</part>

<part>

<name>c_gear_right_steer_cylinder</name>
<copy>c_gear_steering_axle</copy>​

</part>

<part>

<name>c_gear_right_rod_connector</name>
<copy>c_gear_steering_axle</copy>​

</part>

Nothing complex really, I did a little snooping, duplicated a part and named them as needed for my animation.

Later folks, I need to sleep a bit, another work week starting, see you guys next week!

 

[CanadaKen]

I've been reading along as your project has grown. Congratulations! You've done
a fantastic job plus it's been very interesting to see your DC-8 come to life.

CanadaKen

 

[Xpand]

Beware, that code will give you a lot of problems if you don't make the landing gear disappear when retracted. Just check the DSB Hawk. When you turn the rudder in mid flight the nose gear goes through the fuselage and appears on the other side. That's why there is the c_wheel tag on the animation tool. It only steers the landing gear when the plane is moving in the ground and not in the air neither stopped.

 

[Mr.FaosFX]

Beware, that code will give you a lot of problems if you don't make the landing gear disappear when retracted. Just check the DSB Hawk. When you turn the rudder in mid flight the nose gear goes through the fuselage and appears on the other side. That's why there is the c_wheel tag on the animation tool. It only steers the landing gear when the plane is moving in the ground and not in the air neither stopped.

That problem can be solved by checking to see if SIM ON GROUND is true, if it is, the animation executes otherwise it does not. I'll show results of this later, I'm still working out the details, i"Ll have osmething by next week.

 

[n4gix]

That's easy enough to fix though by simply adding a conditional to the script(s) to either inhibit rotation unless the gear is extended, or hide the gear when it's retracted!

 

[Mr.FaosFX]

That's easy enough to fix though by simply adding a conditional to the script(s) to either inhibit rotation unless the gear is extended, or hide the gear when it's retracted!

I've been fooling around with this all morning but have not had any luck. All I have right now is (A:SIM ON GROUND, bool) 1 == I know that if that condition is true, my animation should execute or something but I think there is more to it than that.

I can't seem to find a way to implement a IF CONDITION EXPRESSION style.

or

IF (SIM ON GROUND) IS TRUE do this...

<variable>RUDDER PEDAL POSITION</variable>
<units>part</units>
<scale>50</scale>
<bias>50</bias>​

ELSE

do nothing...​

There aren't any examples out there that show this for FS all I can find is xs style syntax.

 

[n4gix]

You need to think backwards! XML syntax and schema is Reverse Polish Notation...

The general formula is:

(condition) if{ (do something) } els{ (do something else) }

The crucial formatting rules to adhere to are:

1. At least one space between items
2. No space between if and the curlybrace: "if{" not "if {"
3. At least one space after the opening curlybrace, and one space before the closing curlybrace

The following is adaptable for use in any XML script, whether for FS9 or FSX:

  <PartInfo>
    <Name>CJ1_Nosewheel_Steering</Name>
    <AnimLength>100</AnimLength>
    <Animation>
      <Parameter>
        <Code>
          (A:Airspeed select indicated or true, knots) 20 &lt; 
          (A:SIM ON GROUND,bool) 
          and         
             if{ (A:RUDDER PEDAL POSITION, part) 50 * 50 + }
             els{ 50 }
        </Code>
      </Parameter>
      <Lag>10</Lag>
    </Animation>
  </PartInfo>

Note that there are two conditions. If "airspeed" is less than 20 kias AND aircraft is on the ground, then steering via rudder pedals is active, else the nosewheel steering is locked at position 50 (centered).

You can of course change the speed to best suit your particular aircraft...

Note also that I'm using the alternate <Code> schema rather than the <Sim> schema. This allows a great deal more flexibility, since the <Sim> method does not allow conditions!

The general formula for the <Code> schema is:

(sim variable,units) scale * bias +

 

[Heretic]

I'd use "(A:Altitude above ground, feet) 10 &lt;" instead of (A:Sim on ground, bool), since the "on ground" variable causes problems in multiplayer. At least in FSX.

 

[Mr.FaosFX]

I'd use "(A:Altitude above ground, feet) 10 &lt;" instead of (A:Sim on ground, bool), since the "on ground" variable causes problems in multiplayer. At least in FSX.

The problem with that is, what if your in an airport that is -25 feet bellow see level? or deeper? I think the best way to do this is to monitor the engine rpm application and make a decision about whether the wheels can turn or not...as a matter of fact, based on engine application, you can even decide the maximum turning angle for the wheels to make it look realistic in flight simulator that is...everyone knows that if you ram the throttle and turn left, it looks like the front tires are skidding on the runway but the plane still turns a little bit....implementing some code can allow the turning angle to reach a maximum to prevent the wheels from going FULL left steer or FULL right steer, this is native code to the aircraft type itself.

People keeping telling me, why not use C_Wheel ? I believe C_Wheel is hard-coded into flight simulator, it's not even an XML animation defined in makemdl.parts.xml, I've searched for it, it's no where in there. This creates one problem for what I'm trying to implement. I can have BASIC nose wheel steering with the C_Wheel but with it, I will not be able to implement the articulating hydraulic cylinders, as the parts need to be rotated 360 degrees ... then that is where the issue is brought into light, the animation requires adjustments at KEY locations to make sure the rods don't stick out of the cylinder, it would be extremely time consuming to implement this using that technique. And, even if it could be done ... you still need to some how copy the C_Wheel animation tag which does not exist in makemdl.parts.xml hmmm

 

[n4gix]

You are correct, in FS9 c_wheel is a "default animation" that's tied to the ailerons.

Using (A:Altitude above ground, feet) 10 &lt; should not be a problem at all, since it's always based on the AGL immediately below the aircraft. So, if the runway elevation is -25' then the condition will be triggered at -15'...