Apollo 50th: Building Estes’ 1:100 Scale Flying Saturn V

Estes Rockets has a 50^th anniversary Saturn V kit out this year. I picked mine up at eRockets a while back, but be sure to check your local hobby shop as well. This is a 1:100 flying model rocket kit, which puts the final dimensions at 43.25” tall and 8” fin tip to fin tip. This is a challenging rocket to build but will definitely be well admired. I’m going to detail my build and show some of the modifications I’ve made. Sadly, I’m not going to get a chance to fly it on or around the anniversary. Hopefully, I’ll make it to a launch with my NAR Section (NAR.org) in August or September and fly it then, so I can share launch photos at a later date.

This is a challenging kit even for a steely-eyed missile man like myself. I’ve been building and flying model rockets for close to 30 years now. This kit is not an entry point to the hobby. GeekDad has had a few rocketry articles in the past, and I hope to have a rocketry primer article up later this summer, if you’re interested in the hobby.

A Note on Modifications

The stock kit is designed to fly on a single 24 mm motor E. I’ve seen others who have upgraded this to use different motor locations, larger diameter motors, clusters of multiple motors, and staged to fly like the real rocket. These types of modifications will require other changes to the rocket to fly safely. I’ve chosen to build the stock motor configuration. The modifications I outline below are to add some strength to the design with minimal impact on weight. Building light is key to a well-performing model rocket.

Let’s Go to Michael’s Assembly Basement and Build a Rocket!

Most rockets start with the assembly of the motor mount, and while I will skip around in steps to complete sub-assemblies, this is an excellent place to start. The motor mount tube is responsible for transmitting all the thrust from the engine to the rest of the rocket. The motor block is installed with the engine hook and the engine hook retainer. (Engine and motor often get used interchangeable in model rocket circles, and a great way to start a very spirited discussion is to ask which is correct. I’ve heard engine hook is used more often than motor hook.) The motor block is what the thrusting motor pushes directly against, and the hook is to help retain the motor both during thrust and when the ejection charge fires to deploy the parachutes.

Outside of the long motor mount tube, three centering rings are attached. These pieces center the motor tube in the larger air frame and connect the motor to the outer airframe. I chose to add some balsa wood gussets to the upper and lower centering rings. This allows for a stronger load path to the rest of the rocket by stiffening the centering rings.

At this point, I moved to the S-IV-B or third stage of the Saturn V. First assembling the short ring that fits inside the booster. This is where the rocket will split for recovery. The booster section (this is the 1^st and 2^nd stage of the real rocket) recovers under 2 parachutes, the third stage and Command Service Module returns separately. Here is another point where I deviated from the instructions. I installed a balsa wood block in between the centering rings on the connector, in which I mounted a screw eye. This should be a much more robust attach point than the stock elastic loop through the two holes in the centering ring. I installed similar recover attach points later in the main body of the rocket as well.

Then the upper body tube is installed between these two rings. A conical paper wrap is built and will be the foundation for the vacuum formed wrap applied later. I had a lot of difficulty getting this wrap to fit correctly. I should have cut well outside of the lines and test the fit more thoroughly before gluing it together.

Next, we move to assembling the plastic components. CA (cyanoacrylic/super glue) or plastic model cement can be used. If you have access to the plastic cement that can actually melt/weld the plastic together, I recommend it highly. You’ll have an easier time than I did. Components for the Command Module, Launch Escape System (LES) tower, fins, and F1 engines were removed from their respective sprues, lightly sanded, being careful not to remove the alignment pins, sanded, and glued together.

My instructions said to use 2 of the 4 pats of clay as nose weight in the Command Module. I found it odd that only half were used, so I contacted Estes Customer Service and they said to use all 4. This was backed up by data on rocketryforum.com that said using only 2 of the 4 pieces of clay resulted in poor flying characteristics.

Now we move on to what is the most difficult part of this model, the cutting and gluing of the vacuum formed wraps. For those uninitiated, vacuum formed plastic is thin plastic (~0.010”/~0.254mm) that is heated and pulled over a mold using a uniform vacuum. Its benefits are the ability to capture fine details, like the hat-shaped stringers that were needed to strength to the Saturn V in between the fuel and oxidizer tanks, and its light weight. The downsides are it is susceptible to melting when using adhesives like CA and epoxy, which give off heat when curing, and it can be difficult to cut correctly.

To further complicate matters, the interstage wrap is not correct. The lower first stage portion is offset from the upper second stage portion. In all honesty, most people (including a lot of space geeks) will miss this looking at the rocket when finished. I did correct it on mine (though I was off slightly in doing so). Chris Michielssen documents the change needed on his blog Model Rocket Building. If you want to see someone’s build process super detailed to make an amazing version of this kit, check out his 50+ part series of his build.

I marked the body tubes as shown in the instructions for the wraps and accounted for the corrections noted above. The instructions called for permanent spray contact adhesive. I have a cans of 3M Super 77 and Aileen’s adjustable spray adhesive, but I chose not to use those. I knew with the Super 77 I’d have one shot at getting the wraps on and I was not that confident in my abilities. Plus Super 77 is messy and a pain to work with on a good day, and my can is really old. I didn’t want to use the adjustable either. I used plain old rubber cement and touched any lose edges up with CA. I’m mostly happy with the results, but I had a few bubbles in the wraps. Lots of rubber bands and clothes pins were used to hold things while adhesives dried. I think it will survive the aerodynamic forces of flight but we’ll see.

Next, the fins and vacuum formed fairings are installed at the base of the rocket. The fins are glued to the vacuum formed wraps in the instructions. I chose to cut away the wrap and glue the fins directly to the body tube. The fin fairing assemblies should be test fit and carefully checked before. I had some issues getting clean cuts on the fairings.

Which lead to the need to apply some Squadron Putty around the fairings. I also used this to fill seams in the body tubes. Filling the spiral seams would have been smarter to do before applying the body wraps. Sanding off the excess putty near some of the wraps was not easy. I also applied some cardstock panels to the service module to give it a little more detail.

Painting and Finishing

My standard finishing is to start with several coats of primer, alternating between white and grey. I then sand most of this off to get a smooth finish. As sanding the details of the hat stringers would have been very challenging, I modified my process. I sprayed one light coat of white primer and only sanded visible irregularities. Now it was time for the color coats.

I purchased some Testor’s Model Masters acrylics from my local hobby store. A bottle each of flat white, flat black, and aluminum. I sprayed them through my airbrush and had a difficult time fine-tuning the spray. These paints were thin to begin with, and even a small amount of thinning with Testor’s acrylic airbrush thinner made the paint too thin. Spraying the paint straight, though, was also not ideal. For the white especially, I should have moved up to the larger nozzle size. This is not a reflection on the paint but more so my being not used to Testor’s acrylics. The white color coat took most of the half ounce bottle, with just enough for touch-ups and mask sealing. After the white had dried, I started masking for the black coat.

Now masking for this rocket is a challenge. The vertical lines are not hard, as that runs parallel to the stiffeners. However, the circumferential masking is a challenge. What I found worked best was to use a mechanical pencil with the lead retracted to burnish the masking tape down between the stiffeners. I then sprayed a light coat of white along the edges of the tape to “seal” the tape, then proceeded with the black coat. This worked very well! I had very few paint runs under the masking tapes, and the ones I had were very small.

I then remasked for the application of the aluminum paint on the fins, the bottom of the fairings, and the service module.

This was less successful, as the burnishing could not be as strong on the less supported vacuum formed fairings, the multi-colored area underneath prevented the seal, and I started with the rocket upside-down. Despite this the runs were not terribly significant and easy to touch up with a paintbrush. While doing touch-ups I freehanded the hatch and a few details on the boost protection cover of the capsule.

Next, decals were applied. I’m a bit out of practice with waterslide decals, but these went on fairly easily. Some of the decals are very long and skinny, which often is the source of decal difficulties, but I had little crinkling. These decals, however, were very sticky. They grabbed the surface very quickly. I used a flat paintbrush to work back under the decal and repositioned the ones that grabbed where I didn’t want them. I still have to apply a flat clear coat to protect the decals, then it will be complete.

What Is Not Finished

I still have to paint the five F-1 first stage engines and attach them to the display piece. These are not designed to be part of the flying configuration. Also, the way I display my rockets, the F-1 engines won’t be in the rocket often. The kit also included a 1:100 scale Lunar Excursion Module (LEM or the Lunar Lander) from Revel. It looks to be an excellent little model that I plan to build at some point.

Thoughts and Recommendations

This was a rocket that I truly enjoyed building. Many of my builds, both scratch-built and kits, tend to be more sci-fi in style. I do enjoy scale builds as well. This kit definitely got more attention to it than other scale rockets I have built. As I said at the top, it is not an easy build but enjoyable.

If you have built model rockets before or have other modeling experience, this rocket is likely buildable. If you’re looking for more of an entry-level rocketry experience and want a Saturn V, check out Estes 1:200 scale kit. It falls in their “Ready to Fly” skill level. This is available both with and without a launch pad option, if you need a launch pad. This rocket definitely makes a centerpiece for any rocket fleet. I definitely recommend getting it!

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