Tuesday, September 30, 2014

Starting a rocket build

While I very much enjoy building current kits, my real passion is perusing old catalogs and plans so that I can build the rockets that were available when I was a young geek (40 or so years ago – sigh). You can find a lot of the old catalogs here on Ninfinger’s site, and the instructions/plans are often available at JimZ’s Rocket Plans or, if he doesn’t have them, Ye Olde Rocket Plans. What you DO NOT want to do (unless you are a collector with serious bucks) is to spend a couple of hundred dollars on eBay for a kit you can easily clone for about $15.
A while ago, I was looking at the Estes 1973 catalog and ran across this page:
I have cloned the two in the middle (Little John and Wolverine) already, and the two on the far left – the Aero-Hi and Rogue – struck my fancy. I especially like the sounding rocket style and color scheme on the Aero-Hi. I now had the idea for my next build project, so what came next? In this case, I invoked Rule 1 from Part 1 of this series, and think about the build:
  1. Are the instructions and parts list available? Yep – JimZ’s site has the plans for the Rogue and Ye Olde Rocket Plans has them for the Aero-Hi.
  2. Are the parts available? Again, yes. Go to the Semroc web site – my absolute favorite rocket vendor, btw – and click on The Classics image near the top right. Searching the list for the Aero-Hi and Rogue shows that Semroc has all the parts I need, including laser-cut fin sets (Yay!). No decals, but a quick check of the Excelsior Rocketry web site indicates that he has them – the Rogue, Little John, and Aero-Hi are all on the same sheet, saving me from having to buy 2 sets of decals.
  3. Do I have some or all of the parts? In this case, yes, including the Excelsior decals, which I purchased when I cloned the Little John.
  4. Any gotchas in the builds? Pretty straight forward 4FNC (4 fins and a nose cone) construction, with tri-color paint jobs. However, I did notice that the Rogue fins are of thin 1/16″ balsa, which have a tendency to warp when you apply sanding sealer or water-thinned Fill N Finish. Best to paper laminate them, which will solve the warping issue, and add a lot of strength to the fins.
The next steps are to print out the instructions and to gather the parts from my various bins and boxes. Shown below are the components of the Aero-Hi; you can see that I have already applied Fill N Finish (mentioned in Part 2 of this series) to the body tube seams. The old brown-colored Estes/Centuri tubes have little in the way of spirals and often require no filling; however, the new white tubes often have deep spirals, which easily show in the painted model unless filled.
 The 1st step in the instructions for both rockets call for assembling the 13 mm motor mount, which I followed, EXCEPT for cutting small notches in the forward centering rings. The BT-20 main tube is rather small in diameter, and I like to have as much room for the parachute as possible. So I am opting to forego the standard Estes tri-fold paper shock cord  mount in favor of the Quest-style mount, in which thin 100# kevlar flame resistant (but not flame proof) thread is tied around the motor mount tube and passed through the notch in the centering ring. The shock cord is then tied to the thread (see image below). An important point is that the kevlar thread should not be so long as to stick out of the body tube, else the stress of ejection could result in a “zipper”, in which the thread cuts down through the body tube like a knife.
Body tube spirals filled, motor mounts assembled. We will continue on in Part 4…

1 comment:

  1. The Javelin and Super Flea were flown at our first organized launch in 1977. I've always wanted to clone them, but I've never gotten around to it.