P-47D Thunderbolt in 1/18 Scale Totally 3D Printed

[RCPlym]

On 4/16/2026 at 8:56 PM, JayW said:

What is an induction vibrator you might ask? 

 

0hhhh Matron! (In the inimitable style of Kenneth Williams)

[Greif8]

Superlatives fail me Jay, just over the top skills man!

 

Ernest

[amurray]

Oh, God!  Here we go again.  Every time I think I've mastered modelling skills over the past 70 years I see something like this project and am again reduced to pacing my modeling room muttering,

 

"I am not worthy . . . I am not worthy . . . I am not worthy . . . I am not worthy . . . "

 

[JayW]

Let me address some of the comments, as there are many.

 

On 4/16/2026 at 3:01 PM, Mal_Belford said:

Those wing nuts...how did you do them?...as that tiny detail ads alot to the whole impression.

 

As RCPlm stated, its all SLA (stereolithgraphy) 3D printed.  I have a good machine - the Elegoo Staturn 2, good resin - Elegoo standard gray, and a decent although not great slicer software package - Chitubox (free version).  There are other equally good sets of products out there, if not better.   For greater detail, I set my layer thickness at 30 microns. A micron is a "micrometer" which is 1/1000 of a millimeter.  So 30 microns = .03 millimeters = .00117 inch.  I suppose I could go thinner still, but at that thickness the unaided human eye cannot really see the layers well.   So I think that is kind of a standard thickness for this type of work.  For my larger parts I go with 50 microns, and even at that thickness I can get some really good detail.  The trade-off is printing time.  The thinner the layer thickness, the longer it takes to print a part, and the more that printer has to work to finish the job.  I live in fear that my printer will break down one day and I will have to find the sweet spot on another machine, something it took me a while to do on the one I have.  Those wing nuts - well within the capabilites of that 30 micron setting.  The issue becomes mostly fragility (my wingnuts are necessarily thicker than real life, scaled).  Also, when the support connections (similar to sprue connections for plastic parts) become as large as the details of your part, you know you might be adding too much detail.  The wingnut tabs come close.  

 

On 4/16/2026 at 7:58 PM, SwissFighters said:

I wonder how did you replicate the stencilling?

 

Hi Tony - in this case I created decals, and tell the truth not great decals.  I found a military font on the web for free and down loaded it into Microsoft PowerPoint.  From there just create the right scale decal, and print it onto decal paper.  Currently using a laserjet (not ink jet), in hopes of surpassing the quality that my old ink jet gave.  So far unimpressed.  I should have paid alot more money for a printer with more fidelity.  I also hope to be rescued by someone here who can teach me how to make better decals.  I still have the nose art to do and I am afraid I will not do a good job on it.  

 

On 4/17/2026 at 7:49 AM, RCPlym said:

On 4/17/2026 at 7:45 AM, Shoggz said:

Sick of this? 

 

You're joking right? - it's just amazing and I love it!

 JayW is. 🤣🤣🤣🤣 

 

Let's see - am I joking about being sick of the firewall work?  No I am not - I am ready to move on.  I am pleased though to find that my followers do not seem to be as impatient as I am.  Thanks you guys (and gals?). 

 

For all who think this is some kind of magic, I thank you so much for the kind words - here is where the skill comes in.  It is not so much in printing parts.  Anybody can do that with a little practice.  And it is not so much in designing parts; hell the parts I make were designed in the 1940's already - all I do is make adjustments so that they can be produced at 1/18 scale.   And it is certainly not in the assembling and painting no matter how much I wish it were so.  My skill set is in reading engineering drawings, something my career taught me long ago.  What does a dash line mean, what does a solid line mean, what does a phantom outline mean versus solid, what does "reference only" mean versus a hard callout, how to get your part definition from orthographic projections, using drawing trees and lists of materials, determining part effectivities (what block of airplanes use which configuration), etc.  That takes some learning.

 

On 4/19/2026 at 12:24 PM, RCPlym said:

0hhhh Matron! (In the inimitable style of Kenneth Williams)

 

I had to look that one up, as I am not British!  Yeah - the comments on the induction vibrator are not exactly new!  😁

 

OK - next you will see fuel system stuff, something I had neglected and gave me a surprise or two.  Then it is on to the engine mount truss, which is touched by everything imaginable all of which must be accounted for. A real research project.  Stay tuned!

       

Edited April 21 by JayW

[JayW]

The last of the firewall work is done now (until that is, when I find something I missed) - which is the beginnings of the fuel system.  I have some pictures, labelled out of necessity - there is so much stuff crowded together, it is tough to tell what is what:

 

 

 

Belly tank fuel pump with associated lines and its bracket, and a main fuel line "tripod".  And look at all those thumb screws!!    A mess, isn't it?  But it all integrates. 

 

It is not time for the main fuel hoses (one of which that tripod is there for); the engine has to be there first, but I have them modelled in Rhino:

 

   

 

Sometime not long from now those thick hoses will be present on the model, along with the engine.  That tripod you see was not present on early models of the P-47; it showed up a couple of models before my -21RE.  So obviously there was an in-service issue with the hose moving around too much, no doubt under G-loading experienced in combat.  There it is.  And here is the drawing where it is called out:

 

  

 

"Fuel System Installation - Fuselage", Republic drawing 93F65003. 

 

Also I have gone ahead and created and printed and installed a "belly former":

 

  

 

This part doesn't exist on P-47's.  Instead there is a crash protection lattice work of tubes and stuff in which lower skin panels are attached to.  I will not be modeling that crash protection stuff of course, as it isn't seen.  So I have to support my lower skin panels somehow.  That former is the start of it.  I might add that it comforms to the new "bulged keel" lofted surface that I created and reported on a while back.  

 

Also - up to this point my build has been remarkably devoid of breakages.  I broke some stuff on the engine but not too bad and easy to fix.  When modeling with 3D printed parts, breakage is an issue, as the material is brittle.   Those of you who followed my fully 3D printed P-51B build know that I broke things alarmingly often.  Well what did I break?  A wing lug!  Good Lord - those are really important!  One of these:  

 

 

Now, each fitting has three lugs, so six total per side, and this is the forward wing attach; there is a similar aft arrangement.  And I broke off only one lug.  Well I cannot have any more of that.  So after a repair, I created a lug protection cover that essentially mimics the wing side of the joint, even with pins:

 

 

What you see there is revision "0".  I have a rev "A" coming which tweaks the clearances both lug to lug, and also the pin diameter versus the hole diameter.  Important parameters when it comes time to attach wings to fuselage many moons from now.  So these covers should protect those lugs pretty good.  Some may ask why am I going to attach my wings the same way as the real airplane.  And that is a good question.  I mean I like to model things accurately, but this approach for wing attachment (two separate wings attached to a fuselage via single-pin joints) is less robust than a single wing with the fuselage attached to it (the P-51 is that way).  Those joints made of brittle 3D print resin.  And the joints are unseen.  So I do not have a good explanation for you - I hope I do not regret it.  Meanwhile, those lugs must be protected.    

 

All right, it is now time to focus my attention on this beast:

 

 

 

The motor mount.  I proceed with great trepidation.  This thing is so vital to the engine compartment integration, and there is so much to consider, so much to research.  It is about 60% done I'd say, and my research is about as complete as I can make it.  What is still needed is the various heavy clamps that attach so very many things!  Hydraulic lines, fuel lines, oil lines, electrical conduits, defroster tubes, water injection lines, instrument lines, control mechanism supports, electrical boxes - it is seemingly endless.  I intend to incorporate portions of these clamps onto the engine mount tubes as one piece - to better assure proper location, and better for more realistic looking clamps.  You will see the method to the madness soon.  Also, I really need to start modeling up the big oil tank and its associated hardware and lines.  It mounts to the engine mount.  So very important to get that interface right. 

 

Hope you like the progress, I hope to have some pretty cool stuff to report on next time.  Til then, ta ta!

Edited April 29 by JayW

[JayW]

Hmmm - I misspoke.  That belly tank "fuel pump" I mentioned in the last post is actually a belly tank pressure control valve.  Just to be sure....  

[RCPlym]

On 4/21/2026 at 2:08 PM, JayW said:

I also hope to be rescued by someone here who can teach me how to make better decals. 

 

What you will need is a decent graphics package - something capable of producing high-quality tiff images for 'colour' designs and something to produce SVG (vector graphics) that you can design 'BIG' and then reduce them to the sizes you need without loss of detail.

I used to use CorelDraw for vectors (roundels, serials, stencil text etc.) and Photo shop and Illustrator for 'colour' images to print with an ALPS printer.

That one can print white, and with some jiggerypokery, can also print composite colours that are not made of 'dots' like normal printers. It also prints 'dotty' images but they are VERY small dots and are fine for small images.

Sadly, last week the Apple Powermac that I used died a serious death and I now have to find a 1997/98 vintage 2GB-4GB SCSI hard drive to resurrect it. Those are rarer than any rare model kit! 😭😭😭 But I have to get it going again.

 

 

[SwissFighters]

Lol, now you can catch the lug protector instead and break off both lugs at the same time! 😅
Preventing damage is a huge challenge on such complex builds made of resin, no doubt. How do you hold and handle the parts? Would some sort of ball vice make it any easier to support and manipulate the workpiece?

Thanks for sharing Jay - magnificent work, as always.
Tony

[Greif8]

Continued superb work on all fronts Jay! Just Wow!

 

Ernest

[scvrobeson]

There's definitely a museum somewhere waiting for these builds, right Jay?

 

 

Matt 

[TAG]

Jay, you are a frikkin' WIZARD!

 

[JayW]

Last post I stated that it was time to model up the engine mount, and indeed it is.  This thing:

 

 

Take a look at the latest parts that have come out of the printer:

 

 

You see the mount truss proper, a thin gage "baffle", meant to seal between the engine mount ring and the engine aft section, a pair of oil cooler support brackets, two cross beams, and a manual start shaft support tripod. 

 

And the star of the show - the engine mount in all her glory:

 

 

 

What a research project!   You should notice in many places little clamp halves, next to little depressions in the tubes.  My aim is for each of those little depressions to be an accurate locator for a bracket that mounts to the engine mount.  And there are alot of bracket - oh my.  Perhaps these two picture will give you an idea:

 

 

 

Also, and this pair took a very long time to print, I now have two "check fixtures".  The first one is the engine mount alignment tool:

 

 

Note the four small holes at the corners.  I am happy to say that the engine mount aligns as intended, but it was imperative that it be checked:

 

 

 

Now I can throw away the check fixture! 

 

The engine mount, dry-fitted to the firewall:

 

 

No surprises.  I am afraid it is going to "be a minute" until I can install it for good.

 

The second check fixture is the engine alignment tool, which checks to see if the engine is on the centerline, square:

 

 

It took more than 10 hours to print, it is so tall.  You will see the slots on it that are intended to match up with slots on the engine block, for radial alignment.  Here it is in action; first the engine mount is put in place:

 

 

Then the baffle, this thing:

 

 

The baffle placed in position:

 

 

Note it is sandwiched between the engine mount lugs and the engine itself.

 

And with the engine:

 

 

The engine appears to match up just about perfectly, with no apparent need for any shimming or trimming.  And that is a big victory.  

 

At this point it became apparent to me that alot of the further work on the engine compartment is going to require the engine to be attached to the engine mount, and the engine mount attached to the firewall.  Really looking forward to that, BUT before I attach that engine,  I will have to start in on the engine primary cowls, because they will attach directly to the engine via cowl rings, which attach to the engine cylinder heads.  I plan to use the engine itself as the assembly fixture for the primary cowl parts, and I cannot really do that if the engine has been installed onto the engine mount.

 

So that is the next phase of this build - the primary cowls and the cowl rings.  You will see progress on that front next post.  Take care until then.

 

 

 

 

 

Edited May 12 by JayW

[SwissFighters]

Brilliant work!

I imagine the engine (plus prop) is quite heavy? Is there any requirement for a static loading test (or whatever it's called!) to see if the engine support won't deform over time?
Just curious...
But again, brilliant effort - I'm really enjoying watching it all come together.
Tony

[easixpedro]

As always Jay, my Gob has been truly smacked… each update is a masterclass.

carry on.

[scvrobeson]

While the engine and detail are spectacular, the engineering on all of the parts is the most impressive part to me. The jigs, the way things are engineered to fit together, and the structure of it is just so incredible Jay.

 

 

Matt 

Edited May 12 by scvrobeson
Spelling R Hard