7/4/23: As discussed earlier this year I purchased parts for a Patriot Pro several years ago but never built it. After reading the history of the Estes Pro Series II kits I realized I should use the parts I have to build a Leviathan. Leviathan was the first of the Pro Series II and was available from 2012 until 2015, and was 41.5" tall with a 3" diameter. Mine will be 43" tall because I have a longer body tube (Estes/North Coast Rocketry #31755 sold by Estes from 1996-1999). The Leviathan instructions used to be available on the Estes site but they redesigned their site recently and did away with that so I have to go to the Internet Wayback Machine to find it: https://web.archive.org/web/20220113172227/https://estesrockets.com/wp-content/uploads/Instructions/009700_LEVIATHAN.pdf
(of course, it's also available on JimZ's site ; I'm just showing off my Internet geek skills by searching the Wayback Machine for when they last "scraped" the Estes site before the "upgrade".)
I ordered plywood fins and centering rings from Bad Boy Rocketry on eBay and a 24" nylon parachute from Apogee and will use an Estes 29mm engine mount and retainer. I decided I didn't like the original Estes color scheme so I went to StickerShock23.com who have a red & black vinyl decal which would look good on a white rocket with black nose cone. Being too cheap to buy it (and not wanting to wait), I found the Estes decal sheet, copied the page showing the fin decals, opened it in GIMP (the poor man's Photoshop) and changed the colors to black and red:
I'll try printing my own decals on some inkjet waterslide decal paper I bought on Amazon. Simulations in OpenRocket looks like this will require a big engine to fly. Using the biggest Estes 29 mm engine I can buy, an F15-2, it is projected to fly 138 feet and crash before deploying the parachute! If I buy an Aerotech F50-4 from Apogee it should go 782 feet and deploy the parachute at ~350 feet ($42 per engine with a $35 hazmat shipping fee). I might try the Aerotech F67-4W ("White lightning") from Apogee because I can buy 2 engines for $47 and no hazmat shipping fee; the F67-4W is projected to take it 565 feet with parachute opening at 300 feet. With the colors and engines solved, it's time to start building.
I test fitted the fins in my body tube and the retaining rings on the 29mm engine mount and everything fits perfectly. I need to drill four small holes in the upper retaining ring for a Kevlar shock mount per the Peak of Flight newsletter, but the rest of the assembly should be pretty straight forward.
8/19/23 Update:
After some idle time I finally assembled the engine mount, test fitted it, and attached the Kevlar shock mount. Based upon the above Peak of Flight article, I measured the distance from the upper centering ring to the top of the body tube (34" - 8" = 26"). The diameter is 3", so the instructions say to add 1.5X diameter to the length so 26 + 4.5 = 30.5", then multiply that by the 4 strands to get a total Kevlar length of 122". After drilling holes in the upper centering ring with a small drill, I threaded the Kevlar back and forth through the holes, tying it off as described, then attached a swivel clip for the parachute at the top:
8/20 update:
I glued the engine mount into the body, painting glue at 8" in and 4.5" in from the bottom before sliding the front two into the tube. Adding another ring of glue just inside the body I slid the last ring into place and let it dry standing up so the engine mount was even with the body tube. After a couple of hours, I added glue on the bottom of the engine mount then tried gluing the fins in place using my mounting guide but the fins were too long for the mounting guide so I had to glue them one at a time. I glued each fin and left it to dry using a fin alignment guide I built from Tim Van Milligan's book, "Model Rocket Design and Construction" (
pg. 72 of 2008 edition).
Now I just need to put some fillets along the fins, attach the engine retainer, launch lug and nose cone, sand, prime and paint. It's a big one, standing 45" tall and 3" diameter. At least I'm finally getting something large off my build pile.
8/28 update:
I painted the rocket with white primer then sanded the fins and nose cone. The spiral on the body tube wasn't noticeable so I didn't spend a lot of time sanding that. Since this is my first time with plywood fins I didn't realize how much work it was to even round the edges of the fins (compared to balsa). Also, I just received the biggest engines I've ever ordered, a pair of
F67-6Ws, from
Apogee Components along with a Nomex parachute protector and 29mm display stands for my Doorknob and my next soon-to-be-built 29 mm powered rocket.
Before sanding the fins I tried printing my mockup fin decals on decal paper (
Waterslide Decal InkJet Transfer Paper from Amazon), sprayed twice with clear enamel, cut and soaked off the decal to test fitting it on the fins. When I did that I noticed that the red color ink ran onto the fins outside of the decal. Printing the decals worked but it was very hard to position and the bleeding color would be a problem. I think I'll try to paint the recommended colors and stripes by using masking tape (Frog tape). The original Leviathan plans said decals could be "ordered through estesrockets.com" but the were never for sale. Instead,
Estes provided a "free paint scheme" for the Leviathan (I found it on the Internet Wayback Machine from April 2013). I'll post pictures when it's finished.
9/12:
Some progress (and lots of distractions!). I've tackled a variation on the Estes paint scheme used by K'Tesh on the Rocketry Forum when building
OpenRocket simulations for the Leviathan. I've started measuring, carefully cutting Frog tape and marking off areas I don't want to be red (I'll cover the main body with plastic and still have work to do on the fins):
After painting the red, and waiting at least a day for it to dry, I'll mask off space for the black chevrons on the fins and rings around the red stripes on the body.
10/6:
I finished masking the rest of the fins last night (and covered the body with plastic wrap):
I sprayed the unmasked parts with Rust-Oleum Carnival Red enamel spray (a little too liberally) using an extra broom handle in an expended 29 mm E engine to hold the rocket:
Here's my painting stick:
and here's the finished rocket, after waiting ~4 hours and removing the tape.
I updated the
OpenRocket simulation based upon the finished weight and it looks like it should go ~650 feet on an F15-4. The simulation includes using the
JLCR to delay chute opening until 300 feet so it doesn't drift away on the 24 inch nylon parachute.
If I use the F67-6W motor I just bought my Leviathan will fly over 1000 feet! I hope to launch this weekend or at next month's club launch. Next to build, either one of my new Estes Der Big Red Max's, my new Estes Super Nova or Baby Bertha or my Estes/North Coast Rocketry Big Brute (4" diameter!).
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