1:24 scale Ranger 8 NASA space probe (1965)

[bgire]

Hello Folks!

Here's is my latest space project.

I designed and built a 1:24 scale model of NASA/JPL moon space probe Ranger 8.

In February, 1965, just fifty years ago NASA launched its eight (out of nine) spacecraft from the Ranger programme.

The aim: after a direct trajectory journey Ranger was to crash on the Moon. Just before impact a set of six TV cameras was to take pictures of the Moon ground as far as possible and broadcast them to Earth.

These pictures were needed to prepare for the following Surveyor landers and ultimately the Apollo manned programme.

Only Ranger 7 to 9 succeeded. Ranger 8 crashed in the Sea of Tranquillity, not far from the Apollo landing site, four years later.

I started my project after Telford 2012 and focused on a 1:24 scale kit with mixed media (resin, photo etching, turned brass) and full 3D CAD.

Originally I started this project for my own use but Jacques Druel, the owner of l’Arsenal soon proposed his help and to decline this project into a kit on a limited run basis for 28 kits.

This kit has been designed using CAD (Rhino 4, then 5) from the original NASA blueprints which are excellent.

Following is a résumé of my project and build. A complete, more detailed version is available here (in French):

http://www.forum-maquettes-spatiales.com/t1201-sonde-lunaire-ranger-8-prototypage-3d-1-24-montage-bgire#9986

Now let’s introduce the original, which spans 4.6m for a 3.6m height and weighted circa 370kg.

 

 

I worked from the original NASA blueprints (sample here):

 

 

For about 130 hours of CAD work I designed the probe:

 

 

 

 

 

Drawing finished. Here are some renderings:

 

 

 

 

 

Next step: preparing the parts for 3D prototyping (stereo-lithography)

 

 

A few months later the beautifully printed parts arrive at last:

 

 

 

 

 

 

Meanwhile I’d designed two PE sheets. One for improving the master parts, the other for using during the assembly.

The first one:

 

 

And the second one:

 

 

From this point, l’Arsenal began producing a limited run of 30 kits with excellent quality, as always.

 

 

 

 

Next came the first try for the PE sheet:

 

 

By summer of 2014 I received the first batch of parts. About 1 500 parts to check and sort out... amongst them... my kit!

 

 

 

An impression of the whole kit:

 

 

Being involved into the project with a planned sale, I worked on the assembly instructions.

I choose to have them in great detail burned on a CD which includes:

- Assembly steps designed from my original 3D drawings.

- Prototype assembly step by step pictures to help the builder.

- A bunch of picture of the original probe, including Ranger 7 which can be seen in Washington Air & Space Museum.

- Some NASA public domain footage of the original Ranger

By that time (July of 2014) I found a solution to a recurrent challenge: how to render the parabolic shaped fine mesh of the high gain antenna?

The solution came via an article in Airfix Magazine on a 1920’s era car build with details, including a front grid made of brass woven mesh. Eurêka!

I ordered a 50TPI mesh from Eileen’s Emporium and this made my day.

I ordered from Master of Poland a set of specially turned brass rods for the “base ring” braces.

 

 

By January, 2015 I was ready to assemble the prototype. Here is a résumé of the assembly. I used the opportunity to correct and improve the assembly instructions.

A sample from assembly instructions:

 

 

 

Now the prototype assembly:

The six TV cameras in place:

 

 

Mid course correction engine with its tank and support:

 

 

The same fitted inside main bus:

 

 

Viewed from below. The engine with its protective cover:

 

 

The twin platforms for attitude correction sub assembly (motor, tank and command electronics):

 

 

The six main “legs”:

 

 

Some painting work (gloss black under coat and aluminium Alclad2 finish):

 

 

The completed payload. One can see the side cut for the six cameras block with a downward oblique orientation:

 

 

The two solar panels:

 

 

 

Fitting the ten brass braces. Each one has two resin plugs to fit into the legs:

 

 

Attitude orientation plates fitted on the main bus:

 

 

Various connectors are fitted to the base ring:

 

 

 

Then comes the time for the very complex antenna driving gear. This includes thirteen tiny parts and is “functional”: the antenna can be rotated from folded to working position and the star tracker sun shield even rotates accordingly.

 

 

Then came the first challenging step: antenna assembly. I confess I was rather afraid because of the thinness of parts. The step worked well:

 

 

Second challenging step: fitting the formed woven mesh grid. I designed a two part forming jig which allowed to form each sector into a parabolic shape and determine their outline.

 

 

 

 

Done at last! Last challenging step: assembling the four tiny tripods which hold the panels folded during launch phase. Each is composed of tubing bolted to special jigs.

The original drawing was:

 

 

Tripods were made each with three legs (9, 10 and 11.5mm, .4mm diameter brass rod).

Resin parts involved were:

 

 

I was worrying before but I soon realized the rods perfectly “clipped” into the microscopic resin parts. The tripod even stood “on their own” before bonding them with CA super fluid glue.

 

 

Fitting the helium feed pipes to attitude control thrusters (.3mm brass rods clipped on resin parts)

 

 

 

Fitting the six rest pads which hold the antenna folded during flight:

 

 

And I’m done! Fifty years after the original mission, three years after I started my project.

So let me introduce to you.... drum rolls...

RANGER 8

 

 

 

 

 

Some further detailing to be done (various pipes and cables)

This build spans 189mm and is 136mm high with antenna deployed.

It includes 167 parts.

Thank to Jacques Druel from l’Arsenal for helping, sustaining the project and endorsing the risks.

_Bruno

Edited April 13, 2018 by bgire
re-established links with images

[Will Vale]

Wow, that's some very fine work. The parabolic antenna is incredible.

Will

[Hunter Rose]

Wow, that is a superb commitment to a project!

I'm not a big real space model fan, but I really respect what you've done here, fantastic work. And I agree with Will the antennae is incredible, time for a big cup of job well done!

[heloman1]

Pure genius, fantastic work. Congratualtions and thanks for sharing your pics.

Colin

[Eric Mc]

Very, very impressive. Is this a "hobby" build or do you build models professionally?

[Caerbannog]

Absolutely stunning - I saw this on space-Modellers Yahoo Group and it is really absolutely impressive.

What I did not see in the above mail is a link where you can order this gem: http://larsenal.com/

Rene

[Gimme Shelter]

what a masterpiece of modelling - stunning and really impressive

[Eric Mc]

At just under €80, I think that's quite good value considering.

[Ian Shumsky]

Very impressive and inspiring! Many thanks for sharing

[ScarecrowJoe]

Jesus. Christ.

[bgire]

Very, very impressive. Is this a "hobby" build or do you build models professionally?

First: thank you All for your comments and support.

Yes, this is a hobby build: I'm NOT professional. My main job is professor in a mid-size college near Bordeaux, France.

I managed an agreement with l'Arsenal and my friends who own this company. In short:

- I select the model I want to build.

- I start the design and when it's done and ready to print I propose it to l'Arsenal for a limited run.

- If they accept, they do the 3D printing and part casting and sell a batch of 30 (corresponding to the moulds working life) for their own business.

- I get three kits "free" out of this limited run, build it/them... and start another project.

With that method I can get 3D printed parts and professionally cast copies for "free" kits I had designed myself. L'Arsenal gets a new product without spending money for design. A good bargain to say the least.

Next week I'll start my next project on the same basis (plenty of suggestions in the queue).

_Bruno

[Shalako]

Very impressive work!!!!

[bgire]

Hello.

Back on this subject: I repaired the lost links for the pictures, which had been "stolen" during the Photobucket affair last year. Sorry for the delay.

 

_Bruno

[PC2012]

Absolutely fantastic!!!

[MarkSH]

Utterly brilliant from conception, design, print planning and building.....the additive manufacturing must have cost you an arm and a leg! having done similar on a vastly smaller scale I know how much it can cost.

Great work 

[bgilbertsound]

I can barely remember watching a TV broadcast of one of the Ranger series as it crashed into the moon... I would have been around 4 or 5 years old, a true space junkie from a very young age. I wish this model was more widely available, it would be great to have one in my collection.

 

[bgire]

Thanks!

 

I take this opportunity for a new statement:

Last Winter I completely revised the original kit to be no longer cast in resin with PE and metal rods but now full 3D printed with higher resolution (10µm), more details, easier assembly and replacing the costly brass rods with better printed parts.

The two solar cell patterns, which were etched on a brass piece glued to the resin panel are now fully integrated in a solid, full 3D printed part: this solve at last the differential dilatation encountered on the initial PE+resin assemblies, giving them a banana shape after some months, depending on the local weather.

 

This kit is now available again at the same price from l'Arsenal 2.0

For those who bought the original resin version you may want to obtain new printed solid panels to replace the faulty original ones (resin + PE).

Just take a picture of your resin parts and send it to l'Arsenal ([email protected]) and ask for a free replacement.

Edited September 4, 2022 by bgire

[Uncle Monty]

Superb model engineering, well done sir.