1/18 Scale P-38 Lightning

[richdlc]

awesome!!

[Ironwing]

JW

 

Long time no looky, and I apologize for my absence, but you never fail to impress me with both your tenacity and skill. Beautiful work Bud. I hope to be able to get back to work on my beast in earnest soon and keep a closer eye on you...

 

Best

 

Geoff

[JayW]

The nose gear wheel well is coming along - I will show it finished up within a week or two.  Meanwhile I have been working on a side project - the propellers and spinners.

 

Here is a shot of a propeller and spinner un-modified:

 

 

Here are the problems with this part.  The prop blades are too slender at their roots where they enter into the spinner.  There is no opening where the props enter into the spinner (there should be), and the split between the forward and aft halves of the spinner fairing is in the wrong place (it is well forward of the prop roots).  Finally the spinner diameter is too large by nearly a tenth of an inch.  The last item I cannot fix, as the fuselage cowl matches up with the spinner.  The first three I can fix.  It involves separating the individual prop blades, reshaping the blades, and adding back good roots that will connect to a new hub inside a new spinner. 

 

Here is a close-up of the offending prop blades - close but no cigar:

 

 

So off they come:

 

 

Here is a shot in the middle of the reshaping process:

 

 

You see a well scaled picture of a properly shaped prop blade, the unmodified slender prop blades, and three modified blades in various stages of completion (one just about complete and nearly ready for final paint and decals (decals I must create later).  Putty was used to locally build up the blade trailing edge bulge that is missing.  Also, about a half inch of new blade root was added with plastic and aluminum tube. 

 

The new spinner parts were turned on the lathe using large diameter acrylic.  As I have mentioned before, my head stock can be turned at any angle up to 45 degrees, so I machined in at least 4 angles to create the taper I needed, and sanded smooth the sharp corners between faces as best I could.  The larger angles (I think about 37 deg was the largest) were exceedingly difficult to do, as the part moved so far away from the cutting tool.  My lathe is really not designed for large parts like this. 

 

And some shots of the finished parts:

 

 

 

 

It should be easy to see the larger openings for the blade roots.  What is harder to see is the new groove for the more accurate split.  The openings are 3/8 inch oblong drilled holes drilled via the end mill.

 

Well that's a sneak peek.  The next time you see them they will be finished with flat yellow spinners and prop blades with yellow tips and decals of Curtis Electric logos, and of course the serial numbers, part numbers, and pitch limits. 

 

Another update soon.

[Guest]

As always...EXCELLENT !.........Harv 

[LSP_Kevin]

As always...EXCELLENT !.........Harv 

 

Yep, agreed!

 

Kev

[JayW]

The nose gear wheel well is finished, except the gear door fittings which come much later.  Thought you might find the "outside" of the well interesting - a before and after:

 

Before:

 

 

And after:

 

 

Here is the entire wheel well looking at the inside:

 

 

Mostly what was added since you saw it last is hydraulic lines.  The runs are a combination of non-fiction and fiction, partly from not knowing 100% of what the real live wheel well looks like, and also form the variation one sees depending on whihc aircraft is photographed.

 

Here are some more shots:

 

 

 

That last one shows the actuator for the gear door, and its flex hoses.

 

Now it's on with completion of the props and spinners.  Maybe the cockpit is next - what a project that will be!

[JRutman]

Big big improvement on those spinners and props. It is all of these little details that will make the difference in the end.  The nose gear bay is a nightmare of wires and pipes. Thankfully,a lot of that stuff was covered with canvas boots.  Problem is,most restored a/c lack those boots as they live in mostly pristine environments.

J

[JayW]

"The nose gear bay is a nightmare of wires and pipes. Thankfully,a lot of that stuff was covered with canvas boots."

 

Yeah Jerry - that is what you must have been talking about in your (much) earlier post.  I would never attempt to reproduce that snake pit at the aft end behind the canvas.  I didn't even reproduce the canvas!  But the gear door actuator and its lines are in there just about right.  Thanks for looking in.

[JayW]

Work continues on the props and spinners. Am having big issues with the decals; when I overcome them you will see the results. Meanwhile, in parallel with the props, I am working the nose gear door.

 

Here is what I want it to look like:

 

 

Actually what is missing there are the doped fabric covers over the holes. I will include that.

 

What I have to work with is a simple formed sheet of plastic provided by the toy:

 

 

I dremmeled off the little hinges. I intend to use this part as the correctly formed inner skin. I will build it up where it needs it, cut it out where it needs it, and glue on outer skins made of .01 sheet. You see those parts beside the toy part. You also see some of what I trimmed off the periphery of the inner part - lots more to go.

 

And of course (and the primary reason for this post) I have always meant to go after the four "Studebaker Hinge" linkages. This involved some computer modelling to adapt it to the existing (not quite accurate) shape of the door, wheel well, and cutout. What I had to do was desing a linkage that is identical all four places, with dedicated point-designed support fittings on either end of the linkage. designed to interface with differing door inner shapes, and differing wheel well surfaces.

 

 

This shows a completed hinge support (position 2), and some of the painfully small link details. These are cut from .01 sheet, with .02 holes for pins, and spacers to separate the link halves. Manufacturing tolerances were a big deal, as it is hard to do up details within +/- .01 or so, and the parts are so small that those tolerances are significant.

 

Here are pictures of the finished products:

 

 

 

These linkages very nearly do not work. I could not get the individual links and their joints narrow enough and consequently the linkage doesn't want to unfold enough. But some pressure and some minor squashing got enough unfolding to get real close. They are meant to open the door about 94 deg, and I think 90 deg is probably enough. So they will work.

 

Next you will see hopefully the completed door assembly with linkages attached. It will wait some time before I can attach it to the center fuselage. Also, you will see a completed prop/spinner combo.

 

Take care and Happy Hoidays!

[JayW]

I made a copy/past error - here are more pics of the studebaker hinges:

 

 

 

 

 

 

[Wolf Buddee]

Wow, had you used thin brass shim material I'm sure they would have worked flawlessly. Too cool!

 

Cheers,

Wolf

[LSP_Kevin]

Exquisite!

 

Kev

[Guest]

  ..............Harv

[brahman104]

Man those hinges are crazy awesome good!

 

Craig

[skydivin]

very impressive work!