(Click all images below for larger versions)

 

Concorde

I’ve been a fan of Concorde seemingly for ever – what an amazing aircraft! I had an Airfix model of it when I was a kid, but that model disappeared years ago. Rather than buying another kit, I tought it would be more fun to print one. It was almost a toss of the coin as to whether to make my Concorde as Air France, or British Airways. I even mulled over the idea of doing one side as AF and the other as BA, but decided that was probably a bad idea. In the end I opted for British Airways.

I didn’t design the 3D model, but I did modify it to suit the size and printing methodology I wanted, and recreated most of the decals to suit.

The 3D model came as an .stl file from the Printables website by a designer called Clerx. It was designed as 1:144 scale, but since I have some other 1:100 3D-printed planes, I decided to enlarge my Concorde model to 1:100, resulting in a print a bit over 600mm in length. Including the nose probe (which I didn’t print),  the production aircraft Concordes are 61.66m long. The prototype and pre-production models were shorter, at 51.8m and 60.1m respectively.

 

STL and Gcode file formats

STL (STereo Lithography) is a common 3D file format that is not printer-specific, and therefore is a widely used format for model sharing. The end user must then use ‘slicing’ software to convert the STL into a file suitable for printing on a specific machine.

The file format 3D printing machines use is called Gcode. A Program like Cura (or Snapmaker Luban), has all the information about the capabilities of the target printing machine loaded in as a ‘profile’. It will convert the STL into Gcode suitable for that particular printer, by virtually ‘slicing’ the 3D geometery into layers, consistent with the way the printer lays down layers of melted plastic to build up the actual 3-dimensional shape of the print.

 

3D file prep

I loaded the Concorde .stl files from Clerx into Lightwave 3D, resized everything to 1:100 scale and made some minor alterations for the joining of individual parts including flaps and rudder sections. I made many of the parts conjoined, but made it look like they were separate where appropriate. I thought it would be easier to print the pieces that way.

It wasn’t all smooth sailing, however. The transition from supplied .stl to Lightwave, out to .stl again, and then into Snapmaker’s 3D ‘slicing’ software ‘Luban’, caused a modelling gemoetery error with the tail.

Snapmaker’s Luban software is usually good at fixing 3d geometery errors, but not this time. The error also appeared in Cura slicing software, but Cura can’t fix such problems. In this case, the solution was to use the free online 3D model repair tool from Formware – just upload the .stl with the error, and Formware fixes it and keeps Snapmaker Luban (Cura or whatever) happy and things should print as expected!

 

The fuselage was supplied as a 3-piece print setup, with both wings and engines intergrated with the central fuselage section. 

Unfortunately, printing such a large section was going to be over 48 hours – that’s a long time if anything went wrong! Instead, I cut the .stl model up in Lightwave and produced the wings as separate parts, although retaining the engines as part of the wing prints, as per the original .stl file.

I made sure that the fuselage mid section retained the wing roots, to which I added 4 small holes on each side, and 4 corresponding holes on the wings. The idea was to use small nails (with their heads ground off) as joining pins when gluing the wings to the fuselage. It was a construction method that turned out well. 3-D printable joiners were provided for joining the fuselage sections, which were modelled with slots to accommodate the joiners. The joiners had to be modified slightly for the change of scale – with 3D printing you can’t just simply scale things up and down without taking joining tolerances into account.

 

Printing

Here’s a completed wing printed in the Snapmaker A350. Set to print at ‘normal’ quality, it still took over 15 hours to print!

To add to the print time, I accidentally printed two starboard wings! Never mind, at least I already have a completed wing if I decide to print an Air France Concorde!

The main pieces printed: Fuselage centre,  front,  wings,  tail,  and  engine nozzles.

Somewhere over 60 hours printing time for those parts – and the wing elevons* and rudder are yet to be printed!

*Rather than regular flaps, leading edge slats and items for trim etc., Concorde has none of those and instead has six ‘elevons’ at the rear of the wings, replacing traditional elevators and ailerons for pitch and roll control. Three elevons per wing; inner, middle and outer.

 

Joining and gluing

This series of photos shows using nails as pins to join the wings to the fuselage, which were glued with SuperGlue and dusted with baking soda. Baking soda sets off like rock almost instantly when it combines with the SuperGlue, eliminating having to hold the parts together for more than a few seconds while the glue bonds the parts together. The baking soda/Superglue combo also works like gap filler, and can be sanded smooth.

Tip: I discovered that if you keep SuperGlue in the fridge, it lasts for ages, even after the tube has been opened!

Locating the nails into the holes I modeled into the wings.

A bit of tweaking with a bench grinder so that the nails would go into the fuselage holes with just the right amount of resistance for a snug fit.

The wing roots were coated in SuperGlue, then the sections were pushed together and the join dusted with baking soda.

 

Painting

The glued model was now ready for a number of coats of automotive spray putty, wet sanded in between coats, to remove the print layer lines. I could have printed the model with Snapmaker’s ‘Super Fine’ quality setting, but as it was using ‘Normal’ quality, it took over 60 hours. Due to the smaller layer height and thus extra layers required for the print, ‘Super Fine’ would have probably required three times longer, or more! …and I would still have had to give the print a few coats of primer and top coat.

I decided not to glue the tail, as I figured it would be easier to apply the decals if the tail was separate…. and it was! Besides, as you will see later, I had a major problem with the tail.

Various stages of primer and wet-sanding in between.

Finally, the main surface was smooth. The flight control surfaces were also printed and primed. Notice the small holes in the corntol surface actuator bulges – the flaps will be joined to the wings later on using glue and printing filament as locating pins.

Gluing the filament ‘pins’ to the actuators in preparation for gluing the flight surfaces to the wings and the rudder to the tail. Gluing was done over a bucket of baking soda, which was dusted onto the wet glue to make sure the fulament held firm in the slightly oversized holes. Standing parts up in the baking soda made for a handy holder when applying glue.

A few coats of white spray paint followed the many coats of primer, with light sanding in between coats. This process took a few days to allow for drying time in between coats.

The only other paint needed was black for around the engine exhausts, so the model was masked with Yellow Frog Tape (for delicate surfaces) and an old supermarket catalogue!

Black engines! In order to make engine masking and painting easier, the flaps had not been fitted. For this photo, the flight control surfaces filament joiners have just been pushed into their mounting holes, and are yet to be glued.

The included stand as originally modellecd wouldn’t hold Concorde up properly, as the slot in the fuselage bottom wasn’t in the correct position at the model’s centre of gravity. Rather than cutting another hole inn the fuselage, I modelled a collar piece to sit over the top of the stand arm to prevent the model from tipping over backwards.

 

Decals

The decal artwork was supplied as a PDF for printing onto water transfer paper. I used the laserprint verion, but an inkjet compatible version is also available. However, it was at 1:144 scale, so I redrew most of it in Adobe Illustrator at 1:100 scale, and added some detail that the original artwork omitted. The only remaining original art was the British Airway flags for the tail and the British Airways flag and wordmark for the front fuselage sides. 

I came across many great websites with lots of ‘detail’ photos of Concorde, which made fantastic reference material which could be turned into decal artwork with Adobe Phortoshop and Illustrator. Particularly helpful for reference material was www.concordesst.com

Many of the photos could be used for decals, with a bit of straightening up and perspective warping in Photoshop, but the Rolls Royce Snecma engine decals had to be redrawn almost from scratch in Illustrator.

Drawing the canopy windshield (in-flight) decals were a bit of a fiddle to get right, but using paper templates and modifying the artwork as needed got the job done. Below is the canopy windshield decal development in Photoshop, overlaid on a phone camera picture of the Concorde model canopy area, viewed from the top (front is to the right).

From this, a few test windshield images were printed on paper for test-fitting, and the design tewaked until correct. The final windshield artwork wasn’t as tapered as I had originally thought it would have to be, but the test fitting paid off and it ended up fitting like a glove to the Concorde’s curves.

Same procedure for the canopy side windows, also drawn in Photoshop.

The completed A4 decal sheet, with mostly new artwork. I duplicated many items, just in case I wrecked some when applying the decals. As it turned out, I ruined one of the tail flags when applying it, so it was good to have a spare without having to print a new sheet.

The decal sheet was initially laser printed on paper and test-fitted, and tweaked as necessary before comitting to printing on the water transfer sheet.

 

Mirror Imaged 3D Prints!

When doing the paper decal tests, I realised that Lightwave had mirror imaged everything and that the doors and tail rudder control actuators were on the wrong sides! The error wasn’t apparent with the wings and engines, as they are asymmetrical. As there were many coats of paint on the fuselage resulting in the windows and doors being relatively smooth, rather than recessed, the mirrored print wouldn’t be a problem there, as the error would be covered by the decals.

Unfortunately the tail was a different story.  With my 3D print coming out mirror imaged, the  actuator bulges in the tail wouldn’t match the decals and would obviously look incorrect, especially to anyone fimiliar with photos of Concorde’s tail. Concorde has a split rudder, so it needs two actuators. The tail is too thin to put them internally, so they are on the outside, one on each side; upper on the right, lower on the left.

The only solution was to print and paint another tail!

Here we go again, with the two actuator bulges on the correct sides of the tail this time!  The vertical parts are support material, to hold up the protruding horizontal fairing near the top of the tail (VOR aerials, one on each side) and the actuator bulges, as the layers are added, one on top of the other. The brim around the base of the tail is to provide extra grip to the print mat during printing. Both the support material and brim are broken off when the print is completed.

 

Decal cut-outs

As the decal transfer material isn’t flexible and would have cracked if any attempt was made to shape it around the actuator fairing bulges, it was necessary to redisign the tail flag art to include actuator-shaped cutout areas (and then paint the actuators later on after the decals had been appplied).

To get the right shape for the decal actuator cutouts, I made a screengrab of the tail side view in Lightwave. This made it easy in Photoshop to get the cutouts aligned properly with the flag artwork. Shown below is the starboard tail side, with the cutout areas in white. When overlaid on the flag artwork, the cutouts were in the correct position. The actuator fairing bulges would later be painted over with red enamel.

 

 

Painting the tail actuator fairings

A mix of paints was required: Humbrol Orange Lining Matt 82 mixed with a dash of Revell Silk Fiery Red SM330 , Humbrol White Gloss 22 (to backline some of the colur) and Tamiya Flat Blue (to repair small cracks in the blue of the decal)

 

Decal Details

Although small details are barely visible on the finished model, adding such small details makes a differnce to the overall look of the finished model. Below, for example, is the tail door on the starboard side, just behind the trailing edge of the wing root. The door shape is drawn in Illustrator, and a small detail photo has been placed within the shape. Although blurred and too small to read, on the finished model, small things like this add to the overall result.

The door detail was taken from this image – straightened out with Photoshop’s Transform/Distort tools.

Another addition missing from the original decal PDF sheet, were the Static Tube ports – one set   on each side of the fuselage below the front cabin doors.

 

Decal Application

Applying the decals is always a bit of a fiddle. Doing small bits at a time is the way to go. Using a small, wet paint brush helps with applying the decals and nudging them into position. Removing excess water from the applied decal can be done by soaking the water up VERY GENTLY with a piece of paper towel.

 

Finished (almost!)

The decals have been applied and the tail rudder actuator fairings painted. All it needs is to the whole model a couple coats of clear paint to protect the whole aircraft and seal the decals.