Trumpeter P-47D Razorback

[crazypoet]

Ok, so I have this problem that, once I see something in the reference library and find that it’s very visibly wrong in the kit, I can never *unsee* it.

And while I have zero doubts that there will be uncounted inaccuracies that I miss out of pure ignorance, I do try to fix the ones I find, if it’s something that is visible to even a semi-informed observer.

which brings me to today’s installment... 

First, in the P-47 parts manual, it’s immediately apparent that the control stick has a base mounting flange between the stick mechanism and the cockpit floor.   

Both Trumpeter and Eduard left this out of their respective sets, so I gritted my teeth and built the flange while also making up the boot (that flap at the rear of the boot will wrap around the control cable connector and be secured with a brass clasp when installed)

Next, in every photo i’ve seen of original unrestored examples, the forward Cockpit bulkhead is corrugated.  This is a detail that I did my utter damndest to ignore, as there are just a few angles from which it’s visible.  But, well, damn.

soooo...  some .010 card and .015x.030 strip later...  instant corrugated sheet!  Needs to be primed and painted to match, but I am tons happier... 

 

[crazypoet]

So I finally have the cockpit wrapped up.  Things are resting in place while I sleep on it before gluing the seat and sides permanently in place.

i had one oops during the process - my phone rang as I was running the right side rudder cable and I jumped just enough to put some slack in the line between the rudder pedal and pulley.

i’ll decide tomorrow whether I want to rip things up and redo it, or if I can snug things up elsewhere.

i also have a bit of touch-up to do before moving on to the next step - but either way, the pit will be done tomorrow, leaving me ready to move on to bigger things (or at least bigger *parts* of things!)

 

[CrankyCrafstman]

Looking good Crazy

Ron G 

[crazypoet]

I ordered a set of braided lines and spark plugs from ANYZ, so while I’m waiting on them I’m going to do the supercharger assembly.  It has some interesting bits and pieces and materials and it’s a great practice space for NMF stuff in a place where I can hide my worst bit of experimentation.

The hot side of things is steel and the cool side is aluminum - I’ll have some fun playing with different NMF approaches while waiting for the fiddly bits of the engine to arrive

 

[HubertB]

Be aware that the R-2800 had pressurised ignition lines (to avoid arc-sparkles at altitude). Therefore, the ignition lines were metal tubes, and not braided cables. This is one instance where a smooth wire will be more useful than a braided one.

Hubert

 

PS : and I love that cockpit

[harv]

Oh my. Lovely work buddy !!.......harv 

[crazypoet]

5 hours ago, HubertB said:

Be aware that the R-2800 had pressurised ignition lines (to avoid arc-sparkles at altitude). Therefore, the ignition lines were metal tubes, and not braided cables. This is one instance where a smooth wire will be more useful than a braided one.

Hubert

 

PS : and I love that cockpit

Timely reminder!

[CrankyCrafstman]

17 hours ago, HubertB said:

Be aware that the R-2800 had pressurised ignition lines (to avoid arc-sparkles at altitude). Therefore, the ignition lines were metal tubes, and not braided cables. This is one instance where a smooth wire will be more useful than a braided one.

Hubert

 

PS : and I love that cockpit

I went through the P &W R-2800 book and did not see one photo or discription that said/showed they had tubes for spark plug leads. They had a pressurized ignition ring but not the plug wires. Plus they all didn't have pressurized ignition systems.

Ron G 

[crazypoet]

I’m going to dig into the references on the engine - thanks all for the notes!  I would not be even close to where I am without y’all looking over my shoulder and poking at me when I get something a bit off

most of the good pics I have are restorations, but I know I’ve also seen some good pics of early D revs floating around.  I’ll post what I find and go from there

[crazypoet]

So I’m starting to muddle along on the interior ductwork.  It’s really kind of interesting from an applied engineering standpoint.

The engineers who designed this thing really knew their stuff.

Most of this will be hidden away when I close up the fuselage.  That said, the interior ducting from the intercoolers out is not only visible but will have some nice Eduard PE representing the intercoolers themselves.

You’ll also be able to see at least part of the exhaust and supercharger assembly if you decide to take a peek up its arse (who does that to an airplane anyway? Seems to be a bit personal, if you ask me...!)

Due to the way the parts are engineered, I’ll have to prime and paint those internal surfaces before joining the duct halves, which makes the seams something of a challenge.  

from there, it’s pretty straightforward 

I found some great pics of the actual power train online (which might make for a fun project itself down the road!), and I’m using those to inform my paint/assembly work

 

[crazypoet]

I’ve been happily playing around with the innards of this thing, and it’s getting towards the point where I have to put the toys and powders away and actually pull it together so I can get on to stuff that people can see without a flashlight and dental mirror... 

I’ve played with a couple different approaches to the bare aluminum and steel plumbing, and found an approach that works well for me.  

Using Mr Surfacer and Tamiya Flat aluminum as the base for the cold side of things, I differentiated panel materials with Uschi iron and steel powders, then dirtied things up with Tamiya weathering powders.  I like the way they came out.  

The hot side of the plumbing I did with Uschi iron and steel powders over a gloss black base.  It looked gorgeous, but also flat wrong - a gloss coat was exactly what I should *not* have used for this.  I should have used a dark gray flat base coat instead.  The Tamiya powders helped to mute things a bit but if this was on the outside I’d be stripping it down and re-painting from scratch.  

Now on to the nuts and bolts.  I think I understand why the good folk at Trumpeter decided to include all of this stuff.  

First, parts of it will be visible, even more so with the Eduard exterior PE set - it opens things up quite a bit at the Oil Cooler and Intercooler discharge vents.

second, I’ve seen some very interesting maintenance and damage pics of the P-47 and they would be all but impossible to replicate without at least some of the plumbing present.  I don’t know if that’s a good enough reason for them to take this approach, but I can at least see their reasoning

And... all that said... I do wish that, having gone to all the trouble to engineer the plumbing, that they had gotten it right, dammit!

There are some glaring errors and messes in areas that are potentially visible.  The exhaust, hot side of the supercharger and the piping from the compressor to the intercoolers are all just... wrong.  Like head-scratching, whatinthehellweretheysmoking wrong.  Ejector pin marks with in the middle of visible panels...  bad overall fit (including areas where two designers were obviously not comparing notes and left mismatched pins and holes here and there...)

And you can actually *see* some of this stuff.  

the longitudinal fit of the completed assembly is also a bit iffy, so I’ll use canopy glue for flexibility on some of the joints along with some judicious trimming and sanding to ensure it all goes together cleanly.

whats worse is that they had available some amazing references out there, including the whole naked guts up on display - with signs and airflow arrows, no less!  Instead it seems that one of the Trumpy engineers used an old Army Air Corps air-flow schematic as gospel.

such is life!  I’ve had some fun with this and it’s getting on time to put all the bits together, fill the gaps and shoehorn it all together...

 

[crazypoet]

On 9/30/2019 at 10:22 PM, crazypoet said:

I’m going to dig into the references on the engine - thanks all for the notes!  I would not be even close to where I am without y’all looking over my shoulder and poking at me when I get something a bit off

most of the good pics I have are restorations, but I know I’ve also seen some good pics of early D revs floating around.  I’ll post what I find and go from there

The ignition wiring I've seen in both restored and original engines *appears* to be rubber-coated braided lines, emerging from the pressurized ignition ring.

Does this jive with your own references?

[CrankyCrafstman]

19 minutes ago, crazypoet said:

The ignition wiring I've seen in both restored and original engines *appears* to be rubber-coated braided lines, emerging from the pressurized ignition ring.

Does this jive with your own references?

You are correct, they were a braided wire, similar to what was used on automotive engines of the time, but of a much better quality, better noise/ static suppression.

Ron G 

[Axeman]

Great job on the cockpit!  Looking forward to seeing more. 

[crazypoet]

Puttering along with the front of the engine.  

holes drilled for the spark plugs, oil crossovers in place and getting ready to attach the rocker arm covers.

for the record, I *love* the ANYZ spark plugs!!!  They seem overly fiddly until you actually work with them.  They have a pretty robust stub that sits neatly into a .33” hole.

So far everything is fitting nicely, though I found an interesting hitch on the rocker arm covers, reinforcing the old adage to test fit many before gluing once...

to align properly with the pushrods, you need to force a slight bend in the oil crossovers.  So I’ve temporarily connected the pushrods with rubber frisket so I can get everything properly aligned...

 

[Jeff]

[Bomber_County]

20 hours ago, Jeff said:

Pass the chips Jeff..........

[crazypoet]

Greetings all!  It’s been a minute or two since I had bench time - too many distractions and the odd bit of familial   drama...

but I’ve made a tiny bit of progress...  the engine has the base painting done and it’s ready for final assembly, connecting lines and weathering

I did a fair bit of head-scratching on how best to attach the Anyz braided lines to the ignition ring, before remembering  that canopy glue is a wonderful thing for any number of odd bits.  

Each connector on the ignition ring has multiple wires, so I cut and glued the braided lines first, then glued them to the ignition ring.  Looks a bit like someone one having a truly bad hair day at the moment!
I’ll cut each wire to length And glue to the spark plugs and such after I assemble the engine

 

[DocRob]

16 hours ago, crazypoet said:

 Looks a bit like someone one having a truly bad hair day at the moment!

He he, I remember that expression from my P-47 build, but used wire instead of Anyz. Somebody wrote here, that he fiddled thin wire through the Anyz braided threads to gain a little bit more strength. This way it would be easier to glue the lines into pre drilled holes, I guess.

Cheers Rob

[crazypoet]

Managed to get a bit further on the engine - it’s beginning to look a bit like an engine now...

 

[sieben]

I like your work .

 

 

 

[Sir Desmond Glazebrook]

On 8/28/2019 at 3:27 AM, Ryan said:

yes #2 is no big deal.

[crazypoet]

Step by slow step!

i keep hoping for more Bench Time, but it comes in drips and drabs over the holidaze...  

at any rate, I did finally have a chance to finish the engine.  I debated some additional hoses And such, but they would be mostly buried, so I decided to pass

also, since the cowl will be on and closed, I didn’t pay *too* much attention to the back and side views of the engine.

the parts that might be visible through open cowl flaps will get a bit more attention later, but for now this is it.

Now, on to stuffing all the plumbing inside and closing up the fuselage...  that will take a bit of hammering and sawing, and possibly some explosive 

 

[harv]

AWESOME !!.....harv

[TJTX]

Wonderful stuff. I'm working on my TBM engine and came here for ideas and inspiration.   I love the way you've brought the engine to life and especially the wiring harness.