Discussion in 'Scale' started by Crawf56, Feb 2, 2019.
Here is a reference crosscheck drawing of the S-IC outboard engine fairing:
No biggie... just showing the option if someone wants to build a better mousetrap...
man she looks awesome! beautiful job so far!
Preparing the other Fairings for assembly. I have always found vacuum-formed parts difficult to sand (because they tend to deflect), so most of what you see was done with an xacto knife and scissors.
Test fitting a Fin in the Fairing. When I did the first Fin/Fairing installation, I had to rotate it a bit to get proper Fin alignment.
The flash that is along the base of the Fairing (right side of pic, near purple xacto knife) was left there on purpose. I am trying to leave enough material for a good glue joint with the Main Tube.
And, another Fin/Fairing epoxied in place.
Here is what I did on mine, still for 24mm motors but you get the idea. You might also note the internal launch lugs.
Way to re-purpose leftovers!
I like your design, but I feel that I must re-state: The structure for the Estes Saturn V can handle E-engines as-built. Per Estes, when you move up to F-engines, the structure can have problems.
Fairings and Fins onboard. Still need to add fillets.
OK, time to be honest: Fin alignment was a struggle for me. Showing my dirty laundry....
From the side, the fins look ok. And I got them fairly straight up/down. But some of the fins are not aligned as well as I hoped.
Not really an option to rip off and re-apply the Fins. Ever forward....
I wanted to give myself flexibility to go with 24mm F's. Also, when I built one in my youth, the motor mount took off a split second before the rest of the rocket.
Also having troubles with the 3M 77 spray adhesive. Not sure if I will use 3M 77, or epoxy, or maybe foam-safe CA, for repair.
I had the same issue using 77 on my wraps. It did not hold the ends down. I used a very little bit of thin CA just at the edges. It’s been almost a year since I built mine, and they have not lifted since.
Aside from the 3M 77 and 90 sprays, I have seen others recommend Beacon Foam Tac.
Suggest you test on a piece of scrap styrene before using any new adhesive.
Some brands of thin CA and contact cement will crumble vacu-formed styrene.
FWIW, the CA I used was store-branded BSI.
I am an engineer, and have been one for 30 years. And I have found that, after you do something...….you figure out a better way to do what you just did.
After this process of attaching the Fins and Fairings, I think I figured a better way to do it.
Essentially, I should have cut the bottom out of the fairing, along the dotted shown. This would allow me to:
Glue the Fairing in place, allowing me to put generous amounts of epoxy on the outside and INSIDE of the Fairing.
Once the Fairing had dried, I could slide the Fin in place. I could put generous amounts of glue, and get the Fin aligned as needed.
Lastly, I could make a flat Base for the Fairing from left-over plastic, and attach it to the underside of the Fairing. This would allow me to make a better fit to the Main Body Tube, also.
The idea came from the Apogee video instructions for their Zephyr rocket, and from the online build thread mentioned earlier.
Here is where I would cut a little notch for the Fin to go into the Fairing. But since everything is already glued, I will leave the model as is.
OK, I got my Sirius/MO fairing+fin polyurethane combos.
Weights are: 16.0, 15.3, 16.6, 15.5 grams each.
For reference, stock shroud + fin are 5.1 g.
Thus, figure + 43g / 1.5 oz of extra weight to the rocket.
That's the price you pay for perfect look and stronger (semi-indestructible) fins.
Adding the fillets for the Fins and Fairings. After I get all the Fins glued, I will work on some of the "unwrapping" of the wraps.
Epoxy on the bottom of the fairings to add strength.
Cut-outs at the base. Just "eyed"
Ok, wraps on the upper 3rd stage.
The reduction/cone wrap gave me some fits. Had to use an xacto knife to cut slits in the lower half of the cone to get it to fit the existing paper wrap.
Did some tests using the Foam Safe CA that I use on some of my RC models. Seemed to bond good between a cardboard tube and some scrap vacuum-form plastic.
Attaching the outer "piping". Used foam safe CA, to be followed by some epoxy reinforcement.
Perhaps a historical hold over. The original 1236, K-36 was sold back before Estes sold any E motors. These newer Saturn Vs being its descendants, use the same motor. Although the original had an interesting switchable engine mount that could take either a D size mount, or a C-cluster (X3) mount.
I still have my built 1236. It flies pretty well on a D12-3. It is slow off the pad and apogee is kind of low, but the chutes deploy okay. And that's without the transparent fin extenders. I never can get those things to stay on.
Attaching the wire 'hook', which is part of the CSM/Lander parachute apparatus.
And the Control Nozzles (RCS - Reaction Control System) for the Command and Service Module.
The "hook" also seems to represent this antenna. Does anyone bother to put one on both sides?
I built and flew a straight-out-of-the-box Estes Saturn V (#2001 - the one with the card stock stringer sections) for the opening flight of NARAM-31 in Manassas, Virginia way back in 1989. That day was cloudy and windy, and she barely made a 'pop-gun' flight on an Estes D12-3 of about 200 feet. Winds caused the upper section to be caught in some trees (lower section recovered fine); a fellow rocketeer whipped out his fiberglass lineman's pole and recovered it.
Fast forward to the last day and I prep the rocket for the last official flight on an Aerotech E6-3. Not knowing that the thermalite bunched up at the base of the propellant in the motor instead of going up the moonburner core. Rocket chuffs on the pad and when it finally ignited fully it did a short core-sample flight, destroying it. in full view of Harry Stine and Mary Roberts. She sent me a replacement kit but I never got around to finishing it.
Great looking model.
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