[A&A Models] 1/72 - Dassault Mirage IVA (miva)

Minor progress before the wings go onto the fuselage.

There are seven vents on the upper fuselage of the Mirage IV that are case vents (?) that appear as tubes that either protrude slightly or are flush with the fuselage surface.  I've located their positions as best I could from photographic references and drilled holes that will allow Albion Alloys 0.9mm aluminum tubing to be inserted to represent the vent tubes.  The aluminum is soft and it can easily be cut with a hobby knife.  It can also be shaped with a sand stick, and "bell flared" slightly with a pointed scriber as shown. I wanted to do this before continuing with construction but will not install the vent tubes until after painting.

Progress resumes after a long time away from the modeling bench.  A milestone is reached as the lower wing has been attached to the fuselage without issue.  This required the aft fuselage cap near the tail to be placed also, and the photos below show the progress to date for these stages.  The bottom photo shows the small styrene shims placed at the wing root to assure the join between upper wing and fuselage does not deflect or create an unnecessary gap.




The landing gear improvement process started with measuring the kit parts, referring to photographs and maintenance manual drawings, and recreating the main gear in CAD for eventual 3D printing.


I was able to save the parts both as a combined form, and with separate components that I imagined would make painting and detailing easier.  Here is the group of parts for both versions right off the printer.  The large block-like pedestals (to the left side of the image) are supports that will assist me in alignment before I commit to installing the delicate landing gear.  Also included are some alignment guides for the main landing gear wheels to be used for this sub-assembly.


I cured and cleaned up the printed parts and they certainly have more refined detail than what the kit gives you, with the unfortunate drawback that they are brittle as compared to styrene.  I tried an engineering resin that is supposed to be stronger than the "ABS-type" printing resins to hopefully withstand a bit of handling during assembly and eventual transport.

You can see on this additional image that the two versions (combined vs. separate) can be seen, with the separate set having the torque links and some of the shock absorbers or dampeners printed on their own plinth.  I am satisfied with the results from the combined variation and considered the time and care it would take to clean up five parts vs. a single part.


I am using the Reskit 1/72 resin wheels for this project and intend to attach them to small steel shafts for the needs of strength, alignment, and the typical unnecessary complexity that follow my projects.  To use the shafts (small steel dowel pins) I had to drill through the axle stations on the printed parts, which of course revealed their brittle nature as I attempted to drill through the resin.  Shown below are the original and revised 3D CAD images where you may be able to detect a thicker surround on the revised version, which I printed afterwards.  Not dimensionally accurate in scale, but we sometimes make concessions for functionality.


The last thing to do as I move closer to the completion of assembly is to create a handling stand that will allow me to impale the model on a support jig so that I don't have to handle it again once painting starts.  This was done with two wooden dowels set on centers that matched the separation of the engines' axis.  

Hello

Nice to hear from your work again !
Very impressive work with your printed parts !! it seems nicely detailed !



@+
Fred

Hi Lee
my gosh!!! amazing work for a magnificent bird
cheers
N

Hi Lee,

Once a gain , thank you for sharing.
In fact I thank that we are honored to see an american modeller build « our » Mirage IV so nicely as you do.

I have a colleague who flew the Mirage IV in the ´90s for recce flights over the former Yugoslavia. He told me that USAF was impressed by the efficiency of this old aircraft.

Our turn to he impressed by y our state of the art modelling !

Hi Lee,
it’s great to see you back with your Mirage IV. Stunning work as usual
Looking forward to seeing the next steps !!!
JeF

To install the wheel axles, I had no luck in trying to drill through the 3D printed parts, so a redesign of the main landing gear was made.  I opted to use 2mm brass bushings with 0.8mm holes to be glued in place and allow me to insert the steel dowel pins (1/32") to hold the wheels with a robust assembly.  You can see the CAD images here of the parts:


And the bushings were turned on a lathe, with the exact 1/32" hole drilled in each piece, which matched the width of the surrounding 3D printed parts that were redesigned to hold the 2mm diameter hub.  Here they are assembled and set in the jig that assures they are square and perfectly spaced.


And the alignment jig also 3D printed.  The underside of the part was ideally going to provide exact wheel spacing for additional assembly, but the resin shrinkage prevented doing this without using an excessive amount of force, which you mostly avoid when building models.

Ca me rappelle l'armée de l'air quand j'y était pompier et qu'assurer la sécurité incendie du Miirage IV nous frillait les tympans.

Hello Lee.

the orange or red paint on the hatches as well as the marking on the tilting tanks made it possible to check by the tower or by another accompanying aircraft of the correct recoil and locking of the main gear by aligning these markings.
All Mirage IVA / P had these markings.

Merci pour ces photos Didier mais….le cornichon ?

MDR   ! la photo n'est pas de moi et il n'y a pas de nom ou copyright!
MDR! the photo is not mine and there is no name or copyright! (MDR! laughing out loud! French expression)

Thank you all for your encouraging comments. And especially Didier for the excellent photo coverage of the main gear. I had already seen the line drawings and used them as a basis for my 3D CAD model, which after several revisions, I printed to a representation more like the actual gear than the kit part represented. You may have noted that I only printed the fixed hydraulic manifold for the brake lines on the lower part. I am still not sure if I can find lead wire that thin to represent these accurately for the brake lines and the feed lines going down the back of the gear leg. We shall see.

Lee

Some small advances in preparation for completion of construction have been made.  Most notably, once I commit to placing the nose and probe on the front of the model, there are some critical alignment issues to address.  As I have embedded internals (cameras, etc.) in the nose, it is ready to affix to the area ahead of the cockpit, but as molded, it would be significantly out of alignment.  My solution is to first create an alignment guide to make sure it all goes at least on the centerline, and can be viewed from it's profile to keep the tip at the correct elevation.  My solution:

You will note the nose is painted black, which is not to simulate a radome (as there is not one there) but to allow me to mask around the apertures and clear ports with three small circular masks that will remain in place until all camouflage painting is completed. There is a black surround to each port.

Some major issues with the very poor clear parts that do not mate without significant gaps either with the fuselage or the windscreen as shown.  It is presently a problem still being solved.

And you will also note that the front and rear canopy sills are too wide and had to be re-shaped to match a correct section and not result in huge horizontal slabs that would result in an exaggerated and inaccurate appearance.


And much praise for Mr. Zorg, who is battling the same subject, with a lot of helpful insights into the details and approach to this aircraft project.

An update featuring images with the model finally in primer.  To keep the model at the correct stance, equivalent to what it will be once the landing gear are eventually installed, I fashioned these supports to fit within the main gear wheel wells.  They are temporarily glued in place with PVA cement.


The nose gear is just a section of rectangular tubing.  Note here the nose cone ahead of the cockpit has not been cemented in place until measurements were taken to assure the correct elevations with respect to the profile were obtained.


A general shot of the underside showing that the panel lines have all been filled and all of the small insets have been smoothed into place.  The belly radome will not be fitted until after re-scribing the airframe surface.


The underside again with the supports installed to set the elevation of the nose and wingtips. The turned aluminum refueling probe is from Master.


The last detail involved the main landing gear or specifically the ResKit wheels.  I used ResKit wheels which come as tire, inner hub, and outer hub per each of the eight items needed for the Mirage.  Once assembled (and painted) I had to drill out the wheels without breaking through to the outside hub (7), so I fixed a "stop" out of brass tubing (1, 5) that had a 0.8mm ID.  This was set back to limited the depth, then fixed to the drill bit with a very small amount of CA, backed up by a little tape (2).  The axle hole (6) was now the right size to fit the axle shafts (4).  Note: you can buy small HSS drill bits (3) with the 1/8" shank to avoid using the circuit board drills that break at the slightest provocation.

Wow.
Great progress. I'm glad to see that the project is progressing well.

In addition, your editing is instructive in more ways than one: thank you.

And thanks to Diider NISI for his photos (I'm thinking of using them as a support for an essay)

Lee, Coll, thanks to you: your work has actually helped me with my Mirage IV project and your work has inspired me and given me directions for editing.
I hope you don't mind that I was inspired by what you put into this montage.



Translated with www.DeepL.com/Translator (free version)


Wahou.
Superbes avancées. Je suis content de voir que le projet avance bien.

En plus ton montage est instructif à plus d'un titre: merci.

Et merci à Diider NISI pour ses photos ( je pense les utiliser comme support pour un essai )

Lee Coll,
merci à toi: en fait ton travail m'a aidé pour mon projet de Mirage IV, et ton travail m'a inspiré et donné des voies pour le montage.
J'espère que tu ne m'en voudras pas de m'être inspiré de ce que tu as insufflé dans ce montage.