Sunday, July 05, 2015

Saturn V SA-666, from the top down

Well, after seeing Daddyisabar's post on his attempt at an induction stabilized rocket, the gears started turning. Unfortunately, the belts were also slipping a bit so this crazy rocket is what popped out. First, the name. 'Saturn V' because it is based on the AlaskaPaperModelWorks Saturn-V plans. 'SA' comes from the Saturn designations. You can guess the rest :)

The basic concept is a Saturn V with the gap section removed and the 2nd-3rd stage transition turned into ductwork.  It has small fins, which may be cheating. The concept sounded easy until I started gathering all the scrap parts to make it work. It grew from a light paper rocket to something heavier. I am still contemplating what engine to use. I'm also waiting to see the results of the next test flight of the inductor. I might go big with a G74, or I may make this a shelf model. I never build flying models that are never intended to fly. This one was intended to fly but I don't want to waste a motor just to kill it if the probability of success approaches zero.

Here it is with just a touch-up or three required.

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The build was real-time and somewhat helter skelter. So, I'll just give a brief description of each part, from the top down.

Command Module (nose cone) - Cardstock, from the APMW plans with a wood disc inserted to force it to be round at the base, Also provided a bit more strength.

Service Module - Cardstock only.

LEM Adaptor (transition) - Cardstock, inside swabbed with epoxy for rigidity (used up some leftovers).

Third Stage - Cardstock wrap over a section of the Aerotech 38mm DMS packing tube, which is almost the perfect diameter. Inside is a bulkhead to keep the upper section of the rocket from blowing off at ejection and a short shock tether that is epoxied to the tube wall. A shoulder was made with another section of that tube.

Interstage Transition - This is the upper tip of the motor mount/parachute tube.  It is another section of DMS packing tube. Six stringers connect it to the '2nd stage' body section. It has a 29mm motor hole capped with an Estes retainer. I wasn't sure that I wanted to use a retainer, but these rockets are hard to load. Plus, if it crashes, I can scavenge the retainer with the help from my Dremel grinder. If it doesn't fly, it will be a big waste. Maybe I'll give the rocket to my grandson and recover the retainer later.

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2nd Stage body - The 2.875" diameter paper wraps for the APMW plans don't match any tubes that I have, so I cut down the stuffer from a 3" mailing tube.  I cut out a thin strip of the proper width, which was used to reinforce the edge from the inside.

Air gap - I sized this using Dean Black's latest reference design as a guide. The1st and 2nd stages are connected with 4 tongue depressors. High tech stuff. If I had better planning, or printed more wraps, I could make these blend in better. However, I have put enough effort into this thing. Good enough is good enough.

1st Stage - The tube was made as described above. The fairings, fins and nozzles are cardstock from the plans. I added wood discs at the base of the nozzles to keep them round and attached them to the fairings with 1/8" launch lugs. To stiffen the fins I added big honkin' fillets made from...wait for it...hot glue. This rocket was built with lots of odd crafty techniques. Hot glue, tempera paint, Aileen's Tacky Glue, etc.

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