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NAA P51 D-5 NA-1/18 scale
- Thread starter Geo
- Start date
... Hello All,
The saga continues...
Heres a better look at what needs to be added to the fuselage in order to make it the correct length.
Now that the tail assembly has been cut away, there needed to be a way to rejoin the center section to the tail assembly accurately. To do this locating pins were installed into the center section using left over center holed bar stock. Fortunately, and I dont know why it was there, there is structural detail on the inside of the aft center section. This I used as alignment points for the locating pins and their respective receivers in the tail assembly.
On the aft center section, bar stock was welded into place. Once cured, ABS rod stock was welded into the center hole of the bar stock. The same process was used for the tail section with the exception of the ABS rod stock. The receivers in the tail cone are left open.
The tail cone receivers in place.
The front end pins.
Alignment check...The bottom pin is just a temporary spacer to support the weight of the tail section.
Note that the DFF has been removed at this point.
Check to make sure the sections slide together properly into alignment.
The saga continues...
Heres a better look at what needs to be added to the fuselage in order to make it the correct length.
Now that the tail assembly has been cut away, there needed to be a way to rejoin the center section to the tail assembly accurately. To do this locating pins were installed into the center section using left over center holed bar stock. Fortunately, and I dont know why it was there, there is structural detail on the inside of the aft center section. This I used as alignment points for the locating pins and their respective receivers in the tail assembly.
On the aft center section, bar stock was welded into place. Once cured, ABS rod stock was welded into the center hole of the bar stock. The same process was used for the tail section with the exception of the ABS rod stock. The receivers in the tail cone are left open.
The tail cone receivers in place.
The front end pins.
Alignment check...The bottom pin is just a temporary spacer to support the weight of the tail section.
Note that the DFF has been removed at this point.
Check to make sure the sections slide together properly into alignment.
Nice! 
At this point the two sections are nearly ready for the spacer. However, there is another key issue that needs to be addressed before the stretch can be completed.
On the original, the bottom of the fuselage on the tail cone is flat. I guess this could be more incorrect but its hard to imagine how. This would also need correcting before or in concert with the stretch.
It was decided to remove the bottom pan of the tail cone and to install a lamination of sheet stock along with the lamination of the plug for the fuselage stretch. Once in place it would all need to be sanded to shape.
Here is the tail cone with the bottom pan lamination and the fuselage plug in place.Shaping was done with the center section and tail cone joined to insure proper section geometry since the fuselage is tapering front to back. Note that the fin cap and leading edge have been removed at this point.
An orbital palm sander was used to do the sanding.
On the original, the bottom of the fuselage on the tail cone is flat. I guess this could be more incorrect but its hard to imagine how. This would also need correcting before or in concert with the stretch.
It was decided to remove the bottom pan of the tail cone and to install a lamination of sheet stock along with the lamination of the plug for the fuselage stretch. Once in place it would all need to be sanded to shape.
Here is the tail cone with the bottom pan lamination and the fuselage plug in place.Shaping was done with the center section and tail cone joined to insure proper section geometry since the fuselage is tapering front to back. Note that the fin cap and leading edge have been removed at this point.
An orbital palm sander was used to do the sanding.
This demonstrates what the bottom of the tail cone was versus what it needed to be. The bottom lamination gave me all the material needed with which to make the correction. Once the outer contour was achieved, the inside was hogged out to make room for the leading edge of the rudder.
Next on the list was creating the the curve of the lower center section as it transitions to the lower tail cone. Without the added material of the stretch, this wouldnt be possible.
Note the small step at the front end of the lower tail cone lamination. On the Mustang, the tail cone extends into the tunnel created by the engine coolant radiator.
Work could now begin on the fin and rudder rework. New LE and TE along with the fin cap have been added along with the beginning of the reconfigured lower fin where it meets the dorsal spine. Since the D-5 did not have the DFF, the original fairing detail was removed and new ones would need to be installed.
Note the small step at the front end of the lower tail cone lamination. On the Mustang, the tail cone extends into the tunnel created by the engine coolant radiator.
Work could now begin on the fin and rudder rework. New LE and TE along with the fin cap have been added along with the beginning of the reconfigured lower fin where it meets the dorsal spine. Since the D-5 did not have the DFF, the original fairing detail was removed and new ones would need to be installed.
Heres the next issue to be dealt with. After the H stab seats were brought into the size they needed to be, of course the H stabs themselves were just out of wack and would need considerable thinning and shaping.
This will give you an idea of how much they needed to be reduced in cord. Not only did the H stab seat need reducing, but the tail of the fairing also needed to be reduced in order to keep everything properly sized and symetrical.While these operations bring everything into proper geometry, they are also preparatory for the operation which will create the new tail fairings. If this is out of line or not symetrical, the fairings will be wrong.
This will give you an idea of how much they needed to be reduced in cord. Not only did the H stab seat need reducing, but the tail of the fairing also needed to be reduced in order to keep everything properly sized and symetrical.While these operations bring everything into proper geometry, they are also preparatory for the operation which will create the new tail fairings. If this is out of line or not symetrical, the fairings will be wrong.
The H stabs are near complete here and have had the tips blocked for reshaping prior to bringing them to final thickness. The fairing/fuselage blends have also been put in place. Both are made from Miliput (fine). It took several attempts to get the stab/fuselage blend right. Its a wicked compound curve that goes in all directions at once.
You can see here how much material had to be removed to get the H stabs into print. It was so much, and so not to loose the trailing edge, the H stabs were split into top and bottom and the material was removed from the inside.
The near completed empennage. The surface details would still need to be filled and sanded but the mechanicals were now in print and ready for making the new tail fairings. Ill cover this is my next update. Many thanks for looking in.
Hope everyone is well...
Geoff
You can see here how much material had to be removed to get the H stabs into print. It was so much, and so not to loose the trailing edge, the H stabs were split into top and bottom and the material was removed from the inside.
The near completed empennage. The surface details would still need to be filled and sanded but the mechanicals were now in print and ready for making the new tail fairings. Ill cover this is my next update. Many thanks for looking in.
Hope everyone is well...
Geoff
For this build, I will properly use a word too many bandy about for lesser efforts:
THIS BUILD IS AWESOME!
Hopefully, the markings of a shark mouth will be the cherry.
Regards,
THIS BUILD IS AWESOME!
Hopefully, the markings of a shark mouth will be the cherry.
Regards,
Echo Saul, Awesome!
Question why the knock out block where your alignment pins mate at the plug?
Question why the knock out block where your alignment pins mate at the plug?
Just amazing eye for detail. :pinch:
James
Hi James,
Glad you're still on board. Thanks for the compliment, but this is just prep work and she still looks pretty ratty. Hang in there, I think you'll like what's coming.
Geoff
Echo Saul, Awesome!
Question why the knock out block where your alignment pins mate at the plug?
Moon,
Tell me what you're looking at. Are you speaking of the rectangular openings on the sides of the fuselage?
If that's it, its just a resultant opening because of the way I made the plug. Theyre just clearance for the pins. They get plugged once the tail cone is permanently fixed to the center section.
Paul,
You've hit the nail on the head. Making a toy into...will see if it ends up respectable.
Regards
Geoff
Afternoon All,
The next update starts with an apology for double posting the same photo. The last photo should have been this one. This shows the tail section ready for molding the tail plane fairings. This aspect was the real make or break point. If this couldnt be done, the Mustang would end right here.
Because the D-5 and D-10 didnt originally have the DFF, the fairings for the tail planes are completely different.My plan was to vac form new single piece fairings from resin masters, but first the molds had to had to be made. The only way to get an exact match of the tail feathers would be to mold them in place to insure a perfect fit. This is where the prep work would pay off.
To start, the area to be molded was framed using clay. Alumilite silicone rubber was poured into the cavity and allowed to sit overnight to cure. This is what emerged after the clay was removed.
The resulting mold cavity now has has a glove fit of the tail planes and fuselage. Box was built around each mold and sealed around the edges with clay to prevent leakage of the resin when it was poured.
The process is then repeated for the other side. In retrospect, they did have to be so big. I just wanted to make sure I left room for adjustments if need be.
The next update starts with an apology for double posting the same photo. The last photo should have been this one. This shows the tail section ready for molding the tail plane fairings. This aspect was the real make or break point. If this couldnt be done, the Mustang would end right here.
Because the D-5 and D-10 didnt originally have the DFF, the fairings for the tail planes are completely different.My plan was to vac form new single piece fairings from resin masters, but first the molds had to had to be made. The only way to get an exact match of the tail feathers would be to mold them in place to insure a perfect fit. This is where the prep work would pay off.
To start, the area to be molded was framed using clay. Alumilite silicone rubber was poured into the cavity and allowed to sit overnight to cure. This is what emerged after the clay was removed.
The resulting mold cavity now has has a glove fit of the tail planes and fuselage. Box was built around each mold and sealed around the edges with clay to prevent leakage of the resin when it was poured.
The process is then repeated for the other side. In retrospect, they did have to be so big. I just wanted to make sure I left room for adjustments if need be.
I'm interested in the scribing of the panel lines, especially around the fairings.
Opps, you're still updating your post...
The fairings around the tail plane are different between the the DFF and none DFF birds?! Did not realize this! Wonder if Tamiya addressed that in their 1:32 bird that comes with both tail planes.
Interesting...so how do you reverse the mold?
Opps, you're still updating your post...
The fairings around the tail plane are different between the the DFF and none DFF birds?! Did not realize this! Wonder if Tamiya addressed that in their 1:32 bird that comes with both tail planes.
Interesting...so how do you reverse the mold?
