Heavy Mod - 1/18 21st Century Toys P-47D Razorback

[JayW 1,738]

".....complex mechanisms..... a theme which seems to come up in each of your builds!!!"

 

Craig - I'd wager you were thinking of the "Studebaker hinges" on the P-38 gear doors?  Good God man.  That might bring back my PTSD!

[JayW 1,738]

Dang it - I keep finding reasons NOT to glue the wing halves together!  Could be I am psychosomatically paranoid of it.  At any rate it's real good that I positioned and plumbed the gear door actuation cylinder prior to wing half join - it was pretty easy with access both above and below the area; it would have been much harder with access only in one direction.  So I had to fabricate the gear door actuation cylinder with the help of another really nice engineering drawing 89C38180 (thanks Aircorps Library!):

 

  

 

 

Installed - it is supposed to look like this (from wing hydraulics drawing 93C38604)

 

 

 

Note the 45 deg hydraulic fittings on either end of the cylinder, and flex hoses that end on ribs in the wheel bay.  My goal of course is to replicate that even though it is seldom seen (would have to turn this model upside down to see it).

 

My actuator is made from aluminum tube (.093 inch diameter body with .125 inch diameter heads), which is a pretty accurate scaling:

 

  

 

The white (.035 inch dia) plastic rod is of course the drive rod, which will be finished later when I fab and install the gear doors.  The 45 deg elbow fittings were the toughest simply because of their itty-bitty size.  Again I made use of Meng nuts and bolt heads.  I highly recommend this product.

 

Here is the installation of the cylinder in the wheel well:

 

 

 

 

You can see the previously installed thin hydraulic lines from a couple months ago, and the bulkhead fittings that allow them to be joined to the newly installed black flex hoses (which are made from .032 inch dia solder).   It should make sense why the 45 deg elbow fittings were used - makes for a nice clean routing of the flex hoses.  Also you can see that the attaching end of the cylinder mates with a bar of sorts that spans the front spar and a dedicated intercostal that in turn attaches to a stringer on the upper surface.  Note also the large oblong penetration hole in the station 40 rib.  All that boring wheel well work a couple months ago has paid off as I hoped it would.

 

Don't know why I was so jazzed about this little feature - but it probably has to do with the notion that this detail is seldom seen in walk-arounds, and I always wondered how that cylinder was attached in the wheel well.  Hope you like it.   

[Fvdm 667]

I surely do like it. Great job.

[Out2gtcha 32,869]

Love it! The attention to detail on the cylinder and connections is exceptional

[JayW 1,738]

Mark - how's this?  protectors for the flap linkages:

 

 

Truth be told, I only did this after I popped off the innermost flap support rib. 

 

Anyway, I did that just before I dug into the tip lights.  Things are moving quickly.  Recall that I cut these out of a lathe turned piece of acrylic:

 

 

And I wanted it to look like this:

 

 

So I painted the inside two flat surfaces of the acrylic pie slice with yellow zinc chromate, drilled a partial hole and added red (LH) and blue (RH) paint, and bonded the pieces to the wing tips hoping they would stay in place while i went to work sanding and polishing.  And it worked!  Here:

 

 

Only thing is, the solid acrylic greatly distorts anything inside, so the red lamp looks nothing like it's supposed to, except at certain fleeting angles.  What I like is how the clear surface conformed to the local contour.  It polished up well too with 1500 grit sand paper.

 

Meanwhile, Miss Velma, who has been relegated to a smaller corner of the man cave to make room for the Thunderbolt, needed some attention.  Here she is:

 

 

Any of you remember her from a few years ago?

 

I digress.   As a side project, I have begun the heavy modification of the flaps.  Look at the terrible items I have to work with:

 

 

Job number one is to create some sort of airfoil cross section by grinding/filing/sanding down the nose and raised flat surface:

 

 

That took some strenuous work.  You will see much more of the flaps soon.

 

The RH aileron is done, even a cute little decal:

 

 

It received lots of drill starts for rivets on its newly sanded leading edge, and a nice paint job.  It is ready for installation onto the wing, and the LH aileron is not far behind.

 

Wing surfaces have been painted a couple of shades of natural metal silver, and the guns are now in place:

 

 

Alot better than what the toy came with.  The guns were a tough modification as I described earlier.

 

With 1/18, you have to make your own decals as you know.  Here are the ones I created for the wings (two sets):

 

 

 

 

And lastly, I am into the process of using a Maketar mask for the large US stars and bars insignia for the RH lower wing surface which was poorly represented on the toy (the LH upper was fine and I kept it):

 

 

 

 

 

Next post that insignia will be done as well as a bunch of other stuff.  Til then, and Happy Holidays folks! 

 

 

Edited December 23, 2018 by JayW

[Out2gtcha 32,869]

Noice!

[JayW 1,738]

Well I reached a good stopping point, to coincide with holiday visitors.  I finished up the insignia:

 

 

 

 

 

For those unfamiliar with an insignia stencil process, here is the one I used for the Maketar stencil:

 

1.  Finish the basic wing paint job

2.  Apply the entire stencil, background frame and all.  Use Tamiya tape on the insignia itself to hold it together.

3.  Remove insignia, leaving the frame behind.  Further apply masking.

4.  Paint white.

5.  Re-apply insignia.

6.  Remove the insignia outline, leaving behind the star and bars.

7.  Paint blue

8.  Remove remaining stencil.

 

It worked great, but keeping the insignia stencil parts taped together without shifting was a chore.  You like?

 

Also I finished the RH wing tip to look like the LH one.  Here are a couple of shots of the flap-less P-47:

 

 

 

 

 

Have a great holiday!

 

[Out2gtcha 32,869]

Excellent!!

[LSP_Kevin 29,176]

Wonderful work, Jay!

 

Kev

[MikeMaben 6,607]

It's a Chistmas monster !!  

 

Have a good one Jay 

 

 

[Fvdm 667]

Looks great!

[Shawn M 9,382]

wow

thats looks faaaaaaaantastic

[JayW 1,738]

Hello master modelers - life got in the way, and my work on the Thunderbolt has been interrupted alot.  But I do have a modest update if for no other reason than to let you know I am alive.  So on the wing, the flaps are next up.  Something has to attach to these links:

 

  

 

Recall I had started on the flaps a while ago, attempting to salvage the existing parts:

 

 

And I still might.  But to get the spans just right, and get the leading edges right with the attach fittings, is going to be a little sloppy.  Besides, scratch building control surfaces or high lift surfaces like flaps, can be great fun.  So that is what I am doing.  If it turns out badly, I will revert to plan "A".  

 

I am at work making skin panels (with many hundred drill starts for rivet patterns), the spar, and quite a few ribs:

 

 

 

These parts will make up the main body of the flap, and are all 0.020 inch thick plastic sheet.  After that is done, I will tackle the more difficult leading edge, with its attach fittings and heavily curved skin panels.  Sorta like the real thing!   You may be wondering "why does he bother with lightening holes?"  Here's why - glue together a thin sided closed box with no way for it to breath, and the plastic skins will soften and sag or otherwise deform due to the fumes from the glue.  I found that out the hard way on Miss Velma a few years ago, where I completed a flap box only to see it deformed overnight.  The holes really solve that problem.  

 

Here is a shot at the mostly complete main body:

 

 

There are 9 ribs including the end ribs.  I have also put stiffeners in between the ribs (the actual flap has full ribs in those locations too - I didn't want to make that many ribs).  

 

This shows the end ribs:

 

 

They are two layers of 0.01 inch thick plastic sheet, meant to show the hydro-formed stiffening features on the real thing.  Since these ribs are visible, I needed to do that.  Note also I put in some .03 x .03 rod as a stringer, just to split up the bays and minimize any sagging of the skins.  Finally, note the inboard end rib has a heavy (20 deg) cant to it.  The real flap has this too.

 

Next post you should see a completed main body for the RH flap, and perhaps some work on the attach fittings.  My near term goal is to complete those fittings and test fit the flap on the wing.  Hopefully the flap fittings will line up well with the linkage on the wing, and position the flap properly in a flaps down position.  Fun.  Stay tuned!

 

 

 

Edited January 23, 2019 by JayW

[MikeMaben 6,607]

36 minutes ago, JayW said:

                 But I do have a modest update if for no other reason than to let you know I am alive. 

 

                     He's alive , he's alive !!

 

 

 

[Gazzas 6,918]

Jay,

     Glad to see you back at it.  Impressed you are building the ailerons from scratch.  I have a love hate relationship with aluminum.  I love the way it looks, but I hate how easily it detached itself from plastic parts.  What are you using to hold the parts together?

 

Gaz