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rocketguy101 10-05-2019 05:51 PM

1/70 Apollo Little Joe II upgrade
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This has been a project that has been many years in the 2009, when I was cloning the 1/100th Saturn 1B ) click for build thread ), I found out that YORF member grafgulch produced vacuform wraps for the Saturn 1B. During email exchanges, I learned he also had vacuform parts to upgrade the Estes Apollo Little Joe II to the A003 vehicle. I always loved the big 1/45 Centuri Little Joe II, but could never justify the expense of it to my parents, so I settled for an Estes 1/70, but painted it silver and white like the bigger brother.

So I purchased a couple sets of LJII wraps, gathered up the required tubes, then put it all in my closet and forgot about the project. Fast forward to 2016 and Estes re-released the 1/45th Little Joe II. I bought a couple, and then thought it would be cool to make a "mini me" 1/70th model, so I dug the parts out of the closet and cut the tubes to length and decided to order an Apogee Apollo capsule rather than try to clone the Estes K-30 capsule (or build a Semroc capsule). Something came up, and the parts went back into the closet...

Finally, back in May I decided to get to work on this model. I contacted Paul (grafgulch) to see if he still made the wraps and to see if he minded me posting a build article on them. He gave me the go ahead, so here we go...

First, what do you get when you order the wraps? In the photo you see the body wrap, four sets of fin halves, and four fin fairings. The body wrap is formed with 0.012 inch thick polystyrene, and the other parts are 0.030 inch thick. The parts are high quality, with a lot of detail.

rocketguy101 10-05-2019 05:54 PM

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I will be referring to the 1/45 Little Joe II "Tips and Tricks" thread on TRF for some of the assembly methods, such as finishing and painting the top of the body tube before putting the wrap on.

I cut the body wrap to 5.04 length, then I drew a line down the tube, and dry-fitted the wrap to check for gaps or overlap. It was nearly a perfect fit!

I used 3M Super 77 spray adhesive on the wrap and placed it on the tube, then used rubber bands to hold everything. After letting things set overnight, I used CA to seal the edges of wrap. The wrap went on really nice, and the seam was nearly non-existent.

rocketguy101 10-05-2019 05:56 PM

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The fins and fairings require some sanding to square the parts up and remove some molding flash. It's really easy with big sanding block. I numbered the fin halves as I was cutting them out so I would have matched halves when it came time to glue them together.

I put a piece of sandpaper on a BT-70 tube and sanded the bottom of the fairings so they will fit on the tube later.

rocketguy101 10-05-2019 05:58 PM

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Trimming the fairing to fit over the fin was something I was a little afraid of...I didn't want to trim too much and ruin the fairing, so started by cutting around the molded shape from the inside to give me a flat surface to work on. I just used an X-acto knife, but if I had a pair of curved scissors, I would have liked to see if that made the job easier, especially cutting the short side and the corner. Slowly working with the X-acto yielded pretty good results.

I numbered the fins and fairings in order to match them in case the parts weren't exactly turned out they weren't so I marked the additional cuts needed for each pair and resumed trimming/fitting/trimming. I think small scissors would have made this part go a lot faster! I eventually got all the fins and fairings fitted. There are some gaps that will be filled with putty after gluing everything together.

rocketguy101 10-05-2019 05:59 PM

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I built a pretty standard engine mount following the directions from the Estes K-30 model, even adding the balsa gussets. I cut a set of centering rings from 0.050 mat board.

I had planned on running a piece of Kevlar line through a hole in the top centering ring, looping it around the engine tube, and back out another hole in the CR, but got in a hurry and glued the mount into the tube!!! I will use Kevlar and a standard shock cord paper mount epoxied to the body tube instead.

rocketguy101 10-05-2019 06:03 PM

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I used Testor's orange tube glue to glue the fins to the body. I thought about Tenax (or Plastruct "Plastic Weld") like I used on the 1/45 model per the recommendations on the TRF thread, but decided I wanted a gap-filling glue since I was gluing the fins on top of the corrugated wrap. I did take a pin and poke holes through the wrap and body tube hoping to make glue "rivets" like when I glue balsa fins with wood glue. After drying the fins seem like they are attached really well, and the fairings should provide more reinforcement.

Taking a tip from the 1/45 model, I decided to add the long and short tunnels to the model. I had some scrap styrene that was just under 0.2 inch wide and 0.068 thick which was almost perfect. I cut a 5.04 inch piece and a 1.96 inch piece. The long piece is glued alongside the seam in wrap, just like the 1/45th kit. The other piece goes 180 degrees from that. I made a template for placing the parts with CAD and will attach the drawing pdf later.

rocketguy101 10-05-2019 06:08 PM

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After the fins dried, I used Testor's to apply fillets to the fin root. Then I glued the fairings in place. As you can see, there will be some filling work to do. I will used Testor's plastic putty. I decided to fillet the fairing joint on the that I see it, I wonder if this was a wise move...

rocketguy101 10-05-2019 06:10 PM

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I decided to put the launch lugs on stand-offs so the wrap would not get "rod rash". Somebody pointed out a neat trick that placing two round bodies on a flat surface ensured they were aligned with each other. I used some 1/8" dowel for the stand-off and 3/16" lugs. After gluing and fillets, I was wondering the best way to glue the wood dowel to the plastic wrap. I used a piece of scrap wrap trimming and tested an old method I saw in some Centuri instructions of applying wood glue to the wood (or paper) and plastic glue to the plastic, letting the two glues bond to each other. I also saw in the video instructions that come with the Apogee Apollo capsule the recommendation to use thick CA glue to bond wood or paper to plastic. I tried this with the scrap plastic also. The Titebond/Testor's does bond, but it stayed semi-flexible. The thick CA bonded very well, plus the thick gel is gap-filling. So I used that. I decided to place the lugs on the side with the long tunnel so when it sits on the launch pad, it will look like the pictures I've seen of the real Little Joe II on the pad.

rocketguy101 10-05-2019 06:11 PM

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As noted before, I had to resort to the good old Estes shock cord mount with a Kevlar loop. I used epoxy to make the mount and epoxied it in the tube.

rocketguy101 10-05-2019 06:14 PM

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The Testor's plastic putty did a nice job of filling in my butchering job on the fairings.

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