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PostPosted: Tue Oct 10, 2017 11:20 am 
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Airman

Joined: Thu Aug 10, 2017 2:58 pm
Posts: 44
Hi Guys

I have completed the Left side with the "Firm Fixed Positions". The Front Panel is next.

Same as before...I'm pretty sure I missed something.

If you notice anything I missed, please let me know.

Also, the Flare Gun Port is just a placeholder, I'll finish it up shortly.

Enjoy

Stang

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PostPosted: Sat Oct 21, 2017 8:03 pm 
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Airman

Joined: Thu Aug 10, 2017 2:58 pm
Posts: 44
Hi Guys

Just getting everything laid out in the front section so I can get the Firm Fixed Points in place.

Still, lots of little do-dads to do and a couple to correct, but we're getting close.

As Always, your feedback is appreciated. Please let me know if you notice something missing, incorrect and or needs updating.

Enjoy and let me know if you have any questions.

Stang out

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PostPosted: Tue Nov 14, 2017 6:24 pm 
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Airman

Joined: Thu Aug 10, 2017 2:58 pm
Posts: 44
Hi, Guys

I wanted to get out an update of the Cockpit Plans for the P-51D.

I have pretty much finished all of the drawings. There are few small items left but all the Switch Boxes, Cockpit Items, Ribs, Floor, Seat, Stick, Throttle, Instrument Panel and Base are completed.

I have been working on providing both the "original engineering" for the pieces in case you choose Aluminum to make your cockpit out of, and now the "new engineered" matching Wood pieces, with customization to fit the Cockpit plans. This way you're not left trying to figure out, "How the heck am I going to make that"? :doh:

I have also completed a series of "Tools" that will help in defining the Firm Fixed Points (FFP) with your Cockpit to make life a whole lot easier.

First Up below is the Completed Rudder Pedals with the "corrected" FFP. thanks to Ed "RaceGuy" for helping me get this sorted along with the Correct Adjustments.

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Next up the is the Reworked Rib Station Drawings. In the Pictures below, they are separated by the "Real P-51D Part" and the "Sim Cockpit Plans". This should make it easier to make your station parts and keep them as true to the originals as possible.

Here's the reworked Station 104, Left and Right Ribs. The drawings include the new Master Station and Reference Lines Tool (on the far left), with each part drawing, so you always have your "reference points" readily available while working with the part drawing.

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Next up is the last few Switch Boxes that are now completed. Now, all of the Switch and Instrument Boxes, Parts / Panels, and Pilots Pedestal are completed. :thumbup:

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Next up is the new Tool Series. The first one is the Master Reference Lines Tool, which provides the needed dimensions from the "Side View" point of reference. The second picture is the Master Front Elevation dimensions Tool.


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The next Tool is the Bottom Floor Reference Tool which provides the Dimension from the ground up, so to speak. The next one following is the Top Canopy Rail Tool which provides dimensions from the Top down. Then comes the Canopy Riser Tool. The Canopy Riser Tool gives the FFP's for the point where the Canopy meets the Windshield and its transition. Finally is the Station 75.5 Reference Tool. This is the Firewall of the aircraft and is the only Rib Station that is not purely vertical.


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Next, we move on to the Floor. The original Cockpit Plans have the Base Floor drawings in them, but these new drawings are based on the original engineering so, if you want a completely realistic P-51D Cockpit Floor, you'll need these. The first one is the completely assembled Floor Unit. Then there are a couple of the individual Floor drawings. All of the pieces for the original floor system are now complete.


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Lastly is a Master Frame Reference Drawing, as I have been asked several times about where the Main Instrument Panel is in relation to everything else. The MIP is actually located at Station 101.25 and Connected to Station 104 via an "L" shaped bracket.

More coming, stay tuned.

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Last edited by Stang on Wed Nov 15, 2017 7:15 pm, edited 3 times in total.

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PostPosted: Tue Nov 14, 2017 6:26 pm 
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Airman

Joined: Thu Aug 10, 2017 2:58 pm
Posts: 44
and just as a little teaser of what's close to done.... Anyone know what this is?

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Blue Skys Everyone.


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PostPosted: Sat Nov 25, 2017 4:06 pm 
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Airman

Joined: Thu Aug 10, 2017 2:58 pm
Posts: 44
Hi Guys

I hope everyone's Thanksgiving was good.

I've had several questions about how I created the profile shapes for the P-51D as well as the Parts. Here are the answers and a few pictures to help with the explanation.

The exact shape of the P-51 was defined by its ordinates, which were finalized in a wind tunnel and then either destroyed or lost to history. What are ordinates? They are fixed points in space as they relate to the X, Y, & Z axis. The X-Axis representing the Horizontal plane, the Y-Axis representing the Vertical plane and the Z-Axis representing the depth plane.

Fortunately, I was able to find the coordinates used to define “most” of the Station 75.5 Firewall. The example below represents just 5 of the 35 2D points that were used to define that shape. Unfortunately, the ordinates in the drawing stopped about three-quarters of the way up for the part. The points below represent the 2D (Horizontal & Vertical) profile shape. In this example, the first number is the X Point (horizontal) by units and the second number is Y Point (vertical) by units, as they are measured from the defined starting point of 0,0 in space.

16.000,5
16.102,4
16.199,3
16.283,2
16.369,1
16.445,0

Here is what the Firewall Ordinates look like when plotted out in AutoCAD.

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Then since the 0,0 point is also listed as the “intersection” of the Frame Reference Line (FRL) and the Ships Centerline (SCL), I can then add in these lines by point 0,0. Then it’s an easy task for AutoCAD to Mirror those Ordinate Points on the right by the 0,0 location, to create the left side ordinates, as shown below.

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Now we come to the ENORMOUS PROBLEM. The complete "Ordinates" used for the P-51D overall profile have been either lost, destroyed or misplaced to history over the years. Fortunately, the Firewall drawing does tell me the vertical length of the part. This measurement provides the “missing” ordinate for the Top of the part. With that point, I can then add in the positions of the Upper and Lower “longerons” and then create a tangent curve from the Top Profile point to the existing side ordinates points, to complete the full profile shape shown below.

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Next, I can add in the Cockpit Plan’s Floor Location and Upper and Lower Longeron locations, and then finally the “Part” itself. In this case, I am showing the Station 89.75 Rib parts with the overall profile. Note, the ribs are based on the original rib drawing, then modified for the Cockpit Plans while retaining the original outside and inside profiles, as well as specific details per the original drawing for holes, curves, connections, etc. This is showed in the picture below.

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The complete ordinates for the P-51 A-C are available on old scanned drawings of very poor quality. When you are entering 1,000's of 5-digit numerical number sets, quality and readability are imperative for accuracy. Thus today, the only place I know where a true ordinate set exists, is on Hugh's Technote Site, where Huge recreated from the few readable ordinates across various drawings for the P-51A-C and then mathematically completed the rest.

The P-51 A-C and D models are "basically" identical from the Upper Longeron down. The P-51D's shape changes mostly above the upper Longeron. This means we can use the data from the P-51A-C for most of the shape. As of this point today, everything calculated above the upper longerons is an estimate unless you have a real P-51D available to measure for 3D points...which most of us don't.

The good news is that we do know several key measurements from the Ship Center Line and Fuselage Reference Line to the Top of the Firewall, Windshield Canopy Frame, Canopy Top and the Longerons Center line locations. These provide the data to replicate the part locations to a very precise point, which I estimate to be close to 99.9% accurate. The reasons we cannot get it perfect is because we don't have all the ordinates and many of the drawings contain errors in dimensions, as everything was done with a pencil, triangle and a scale ruler. This means the Cockpit Plans should be accurate to a minimum of 1/128th of an inch or better overall. This equates to 0.0078125 for you decimal guys out there, which is pretty darn close.

The last thing is the overall Top Profile of the P-51 is virtually straight from Station 75.5 to about Station 146, as shown in the pictures below. The main profile changes are above the Upper Longeron, which I have calculated with the actual part(s) dimensions, for everything above the Upper Longeron.

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Thus, with my Cockpit Plans, I am using the same outside profile for Stations 75.5 through 146. I do use all the specific data for the inside profile and mounting hole locations from the original parts for accuracy. This makes for easier building and ensures the shape accuracy.

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I hope that sheds a little light on the P-51D’s profile and how its represented by the Cockpit Plans.

Please let me know any questions you have and enjoy the weekend.

Stang out


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PostPosted: Thu Dec 07, 2017 7:41 pm 
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Airman

Joined: Thu Aug 10, 2017 2:58 pm
Posts: 44
Hi Guys

With this post, the P-51D Cockpit Plans are complete.

They now total 374 individual drawings, all with multiple views and dimensions. I will continue to update these if corrections or un-drawn parts are found. Time to focus on the Spitfire and the F-18 / AV8B.

Here are some of the final pictures.

With the help of Aircorps, I was able to get the missing ordinates for the "top" of stations 75.5 - 146 and now we have a complete and absolute accurate profile for all the rib stations. I have also included for Rib Stations 75.5 - 146, both the original engineering drawing and the Simulator Part drawing. This way you don't have to figure out how you're going to make the part from the drawing. It's all provided for you.

Enjoy and let me know if you have any questions.

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Stang out


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