P-39, FM2, P-47, P-51 Updates:

Blimey I can’t believe I haven’t posted any updates since April…so I thought I should post an update as a lot is happening. The P-39 Restoration has been a particular focus of attention these last few months, with a particular emphasis on the Cabin rebuild.

P-39 Access Door Sta 86:

P-39N-5 cannon Access Door at Sta 86 positioned between the Rudder Pedal footwells. This took a while to create in CAD due to the complexity of the rudder footwells which are only required for positional reference.

The Footwells do exist which means we have a baseline to check the dimensions in-situ before fabrication. All the original CAD 3D models are provided to the restoration shop along with fully dimensioned 2D drawings.

P-39 Drive Shaft Cover:

P-39N-5 Drive Shaft Cover was another interesting assembly because it was decided at the eleventh hour to 3D print the main sections. For this to work the material thickness has to increase to 0.1″ which meant that careful consideration was required to ensure that this change did not impact the interfaces with the existing bulkheads and the Radio Console.

The above images are courtesy of Omnica Corporation.

P-39 Forward Floor panels and Rudder Quadrant Covers.

As you can see the right-hand floor panel is missing and of course the relevant Rudder Quadrant Cover. The left side panel was also created in CAD because there was consideration for replacing the existing panel and Rudder Cover on that side due to the poor condition.

FM2 and P-47:

Moving on from the P-39 the FM2 project is currently on hold as my intent is to visit a few collections in the UK later this year to do further research, particularly the wing geometry. The P-47 has made its very first mention on this blog…another ordinate study for a friend which is progressing reasonably well but with the focus on the P-39 this will take a bit longer than I had planned.

P-51 Mustang:

The P-51 has popped up again after so many years…not an update per se but a new direction for me on the 3D printing side of things. As some of you already know I have been messing around with 3D printing for a while now mainly the SLA resin. Many moons ago I fully modelled in CAD the Tailwheel mechanism, some of which I had already 3D printed. The reason for revisiting this project is to 3D print more of the parts as a test bed for different resins to examine various structural properties, dimensional accuracy and of course, play about with different finishes. Also to determine just how thin I can go with 3D printed parts and still have a workable mechanism.

This P-51 is a side project that will help me devise solutions for the ultimate goal which is to replicate flight instruments and controls.

As you know original instruments for these aircraft can be very expensive and just furnishing a static display restoration project with the original instruments somehow seems a waste when a replica would be sufficient. This way we can make available the original instruments or parts thereof for refurbishing/restoring for an actual flying aircraft restoration.

My budget for this is rather limited for purchasing materials and I also have limitations on the Elegoo Mars Pro print volume. However, I can work within these limitations…it just takes a bit longer! Something like the newer Elegoo Saturn Ultra would be a dream for this sort of stuff…maybe someday!

The resin I’m currently reviewing is the Anycubic ABS-Like washable resin which surprisingly is rather good…now I have the settings dialled in the detail and dimensional accuracy is exceptional. I will endeavour to test some of the engineering resins like the JAMG HE products though they do require a heated VAT. I see a lot of potential for 3D printing parts in the restoration of static aircraft projects. I would suggest organising the CAD workflow so the original parts are modelled to the manufacturer’s exact dimensions and adjustments made only to derived parts thus retaining the original details.

Link to AnyCubic ABS-Like Water Washable resin: https://store.anycubic.com/products/abs-like-resin-v2?variant=43608219484322

Another aspect of 3D printing worth exploring is for making molds and something else I am keen to try is whether it is strong enough for vacuum-forming thin sheet aluminium.

A lot is going on here at the moment with work continuing on the various aircraft whether that be ordinate studies, designing for manufacture or indeed exploring the vagaries of 3D printing.