Estes Leviathan NAR L1 Certification Flight AeroTech H128W-M, Snow Ranch CA, April 2nd 2016
I built an Estes Pro Series II Leviathan Kit with the intent to attempt a NAR Level 1 Certification Flight using an H class motor. The only modifications made fromt eh stock kit were:
1. Installed a 3" diameter parachute shelf 9" below the top of the body tube.
2. Installed a 200lb swivel to the parachute shroud/bridle.
3. Used 30 min epoxy and 2oz. fiberglass to reinforce the stock estes "Tea Bag" shock cord mount.
4. installed a 12"x12" Nomex flame resistance cloth square to protect the parchute and shock cord.
The model was assembled with both Titebond II and 30 minute epoxy. The fin fillets were done with 1 part 30 min epoxy and 3 parts micro balloons. The paint is Valspar from Lowes (took weeks to fully "dry").
By installing the parachute shelf and nomex cloth, the CG was pushed forward to improve the static stability. At this point, the finished model weighed in at 17.8 oz. However, the stability margin a bit below 1 caliber for all but smaller G and F sized motors.
As I was planning to fly an AeroTech H128W-M motor, I needed to add a little more nose weight to get the static margine up to 1.0 calibers minimum. So, in addition to the parachute shelf, nomex and swivel, I added a Jolly Logic Chute Release and a Jolly Logic Altimeter 3 to the forward body tube's parachute area. Now with the rocket fully assembled per above and H128W motor installed, the launch weight was 26.3 oz and the Stability margin was 1.14 cal.
This seems to have paid off.. as the Leviathan ripped straight up off the pad, perfectly straight without a hint of instability or wobble.
The JL Altimeter 3 measured the peak altitude as 2,332 feet.
From that altitude, the model separated the nosecone and reefed chute from the body tube using the motor ejection which fired a little early at 9 seconds after impulse.. but that turned out the be nearly perfectly aligned with apogee. (matched Open Rocket Sim's 9 second prediction and 2300 ft altitude very nicely!) I set the chute release a little high as this was the first time I'd used it.. so I set it at 400' AGL. It worked perfectly. My model drifted about 1/2 mile away, too far to see exactly where. It took my daughter and I about 20 minutes to find it. We first found a nice little Rattle Snake up on the rock outcropping, but also spotted our rocket from that vantage point. The Leviathan landed on some river rocks as you see in the video. This scuffed the paint on some fins and put a small ding/dent on the body tube's top section. But it was definitely still flyable and thus I satisfied the NAR Level 1 Certification requirements! It was a great day. Thanks to Bill Orvis, the Orvis Cattle Ranch and LUNAR for an excellent day of High Power Rocketry!