1/24 Spitfire Mk Ia Airfix 1970 boxing

[uncletony]

I've had this kit in my stash since the early 90s. I bought it for analog work on a game I was working on at the time. It was already very old -- it's the original 1970 boxing -- a kit I built as a kid and loved.

I pulled it down in December and started at it. Lots to like, lots not so great... fun!



stay tuned.

[uncletony]

This kit will probably be familiar to a lot of folks here. While it pales in many ways to the new tool 1/24 Mk IX, the overall shape is decent and in general it's quite accurate.






Clearly the kit was primarily modeled on Mk I museum specimens, leading to the mold makers erroneously copying details that do not belong on a BoB era Spitfire. For instance, the electrical socket on the port wing fillet was not present in 1940, although surviving Mk Is were retrofitted thusly later on. And the large raised line at the top of the fillet represents a doubler repair that would likely not have been present when the machine was on front line duty. (And it is wildly overscale in any case).


Similarly, during the BoB and prior, Spitfires were fitted with fabric covered ailerons. However the fabric ballooned at high speed, causing extremely high stick forces. The (partial) solution was metal covered ailerons, and all Mk Is were retrofitted -- but not until 1941 or so.


Another repair inadvertently copied to the model -- the raised zig zaggy line on the bottom of the fillet is another panel edge doubler repair -- again, present on many museum specimens which were usually sourced from war-weary OTU machines. The "zag" in the fillet edge, which is only present on the starboard side, is to accomodate one of the two parachute flare doors. (Starting with the Mk II, the second flare chute was deleted).


The quarter turn fastener detail on the cowling panels is a wee overdone !


...and the interior walls are pretty thick (1.5mm) and blobby, with the rudder and elevator trim wheels molded directly into the fuselage side.


While most of the gun access panels are removable, there is no other detail inside the wings save the guns themselves and their ammunition boxes. Kind of the Milton Bradley Operation effect. Same is true for the wheel wells.


The fuselage fit is pretty horrible!


The Merlin lump is just that.


The instrument panel is co-molded with former 8. It features clear plastic gauges, with the dial details embossed on the front.  Meanwhile, the former fans out at the bottom to fill the fillet -- in fact the interior shape is actually ovoid.


The control stick is particularly awful!

[uncletony]

Where to start? In my case I started with the rudder pedals :-)

1940 Spitfires were fitted with simple cast alloy pedals embossed with "Supermarine". The kit depicts (in its execrable way) the later two-step pedal -- the higher step was meant for combat, allowing the pilot to sustain higher G-forces. Again, these were not present in 1940, but were retrofitted.



I designed and printed my own pedals. The strap detail, which on the original was supposedly flattened firehose, will be added later:



Next up, the rudder bar and rods.

[uncletony]

The control column was next up.

I've already touched on the misshapen and blobby kit part. The original column consisted of a central tube that rocked fore and and aft for pitch control, topped with a yoke that tilted side to side for roll. The yoke transmitted its input via chain and cable that ran on either side of the central tube. This was covered by a chain guard. The pneumatic wheel brakes were actuated by the bicycle-style brake handle via bowden cable to the valves in the floor. The machine guns were likewise pneumatically operated via the push button at the top of the spade grip. the ring that surrounded the button was notched and rotated between safe and hot positions.

[uncletony]

Next up, the interior tub situation. Unlike how Airfix modeled this 50 odd years ago, the wing fillets are not part of the fuselage per se and do not contribute to the interior volume. Generally speaking, my Spitfire is going to be broken down into the same main assemblies that comprised the original.

My plan is to remove the fillets from the fuselage and create a new "tub." Originally I had planned to vac form this, but a better option presented itself.

I started by marking the fillet borders and fuel tank cover with blue tape.



By shining a bright light thru the plastic, I was able to trace the border on the inside of the fuselage.



I used these marks to thin the plastic with a dremel to about .35mm



At this point it is a simple matter of cutting along the exterior panel line to remove the fillet




In a similar fashion, the tail was removed at station 19 (per the original) and the radio and accumulator hatches opened up.

As I knew I would need to assemble the fuselage many times as I worked out the interior bits, I decided to make the halves temporarily fasten together with tiny screws. In order to properly line things up so the holes and bosses were perfectly parallel to the vertical seams, I created a series of jigs for my drill press.





voilá

[uncletony]

The new fuselage tub is to be printed. This is one of the many early iterations, each one fitting a little better than the last-- yes it is broken in front. The jagged seam will be addressed...

[uncletony]

...first though, the fuselage walls need to be drastically thinned and blobby details removed. The grunt work is accomplished with an end mill and the trusty X-Y table.





The goal is a thickness of ~.5mm. Where the end mill won't reach, a hand held dremel will. The port side shows the desired outcome.

[uncletony]

Frame 11 is a major structural element. Among other things, the pilot's seat attaches to this bulkhead. The kit part is incorrect and sad.


The original is a hollow structure made up of numerous riveted pieces, Here's one of my first attempts at a replacement:



The seat proper was on a removable framework that incorporated the raising / lowering mechanism.



Like the original, my seat framework is locked into place with functional "rifle" bolts (.001" brass wire)




edit: typo

[uncletony]

the kit seat has a lot of problems. It's not really the correct shape, the flare rack holes are too small and yet it is way oversized.


maybe it is designed around this guy. 


My version is based around the early style all-metal seat. Later seats were made of an plastic-impregnated paper composite material.


The seat raising mechanism is functional:

[uncletony]

Frame 9 & 10 aren't really represented in the kit. Frame 9 has the bearings for the rudder bar rods:


Frame 10 has the attachment points for the rear wing spars (still to do).


A test fit of what I've got so far, with yet another iteration of the tub:

[uncletony]

The upper interior portion of the cockpit is a single piece insert. This is another early development piece.

[Davos522]

Oh dear goodness. This is stunning stuff, absolute state of the art. And I do mean Art.

It's funny, twenty-plus years ago, while wrestling with one of Eric Hight's (original) CSM white-metal engines, I made a throwaway comment on the WWI Mailing List about someday being able to fire up my computer and spit out a fully detailed Benz D.III... but what I didn't forsee was the hours and hours of design work that you'd have to put into creating the virtual model before you could push the button.

Hats off, Uncle. Can't wait to see where you take this.

Dave V.

[uncletony]

but what I didn't forsee was the hours and hours of design work that you'd have to put into creating the virtual model before you could push the button.

Thanks much  Dave Yep, I think you nailed it. We live it an age of amazing, accessible tools -- tools I dreamed of when i was a kid, but these things don't design themselves yet...

[KiwiZac]

This is remarkable. I've just spent a few minutes properly absorbing each post - the detail here is incredible! Kudos and bring on the next update!!

[uncletony]

Thanks Zac!

On with it, then. I have spent a lot of time working out the cockpit door. The goal is for it to open and close with a working latch mechanism, fit nicely when closed and hang properly when open. Complicating things further is the canopy track which is at a very slight angle to datum. A lot to juggle and I haven't quite perfected it yet, but it's hopefully getting closer.

The latch turned out to be the easy part. Like the original, pulling down on the lever withdraws the pins allowing the door to open.




Getting the door to fit and open and close correctly has been more of a challenge. This is one of the first iterations of the door, before I fully understood that the top edge of the door was also the channel section that canopy runners run in. At this point I was simply matching what Airfix did, which is to say, wrong. Obviously the door doesn't sit in the opening correctly. The hinges are also quite a bit too large.



A later iteration, with the channel corrected -- of course it doesn't match the kit any more but I'll get to that.

Confoundingly, the curve doesn't match at the rear.


After much trial and error and many iterations, I finally discovered that my door wasn't conforming to the opening because the print (which has very thin walls) was warping due to my stingy use of supports. This version then is starting to get dialed in.