Public Missiles - Ariel

Contributed by Michael Mangieri

Construction Rating: starstarstarstarstar_border
Flight Rating: starstarstarstarstar
Overall Rating: starstarstarstarstar
Manufacturer: Public Missiles
Public Missiles, Ltd. Ariel

Brief:
Single stage HPR sport rocket with parachute recovery.

Construction:
The components are all top-notch. The kit contains two Quantum Polymer (QT) body tubes: a main airframe and a 9" long payload section. The main airframe is slotted, always a nice touch, and the payload section is large enough for most electronics. If you've never used QT before, you must give it a try. The three fins are 1/16" thick G10 fiberglass. Centering rings are 3/16" birch plywood, machined nicely. The motor mount is the most unique part of the kit. This is PML's Kwik-Switch 2000 system which allows easy changes between 29mm, 38mm and 54mm motors. The main motor mount tube is a 14.5" long 54mm phenolic tube which has a threaded adapter retainer on the forward end. Each of the 38mm and 29mm motor mount tubes have a threaded adapter screw mount at the forward end and a centering ring at the aft. Converting the 54mm main mount to accept a 38mm motor is as simple as screwing in the 38mm motor tube. The nose cone is your standard plastic nose, I didn't notice anything special here. The 36" parachute is made of quality rip-stop nylon, nicely constructed with durable shroud lines. The shock cord and piston strap are perfectly adequate and the kit comes complete with the required hardware.

PML's instructions are plain and logical with many illustrations throughout to help with assembly. The first page has a complete list of the included parts and also indicates the CP of the completed kit (although I always sim my rockets using RockSim, which located the CP about 2" further aft than PML's indicated location.) Important instructions are highlighted and the steps are clearly marked.

The Ariel went together quickly and easily. You must sand the QT with 120 grit sandpaper at all points where parts will be bonded. Epoxy will peel off unsanded QT! I used 30 minute epoxy throughout and built it stock with no modifications except for the Aero Pack motor retainer that I installed on the 38mm motor mount tube.

Although I didn't install one, a Kevlar® shock cord protector would be a good idea to install on the piston strap to help protect it from the ejection gases. Since the PML kits use piston ejection, additional chute protection is not necessary.

Although not included with the kit, I used PML plastic rivets to attach the nose cone to the payload bay instead of sheet metal screws. I also used 3/16" Quick Links at each end of the shock cord as well as on the parachute to allow for easy chute replacement. I would have preferred that both these items be supplied with the kit.

Finishing:
I sanded everything with 400 grit paper and then applied two coats of primer lightly sanding between coats. Krylon paint and primer was used throughout. I chose a similar paint design as shown on the PML web site, but picked Navy Blue and Purple for my colors. PML provides a single vinyl decal which I chose not to use. After the paint dried for 48 hours I applied Future Floor Polish for the clear coat. Two light coats and she was done. Results were excellent.

Construction Rating: 4 out of 5

Public Missiles, Ltd. Ariel

Flight:
PML doesn't list the recommended motors in the instruction sheet. Instead they provide an excellent .PDF file on their web site for each kit that lists all the recommended motors for that kit and detailed data giving expected altitude and coast times based on Rocksim simulations. I always weight every part individually and then account for my glue and paint, so I sim all my rockets before flight. Since I built the Ariel as my Level 1 certification rocket, I loaded her up with an H123W-M which my simulations said would put her at 1540 feet. My successful Level 1 cert flight reached 1500' as reported by the onboard PerfectFlite Alt15k.

Preparation is straightforward. Since the PML kits use piston ejection no wadding is necessary and, since I installed the RA38-P Retainer Assembly from Aero Pack Int'l, motor installation was a breeze--slide the casing in, screw on the retainer, and you're done.

Both of my flights have been on H123Ws and both were picture perfect. Nice straight boost and ejection just a bit after apogee. (I did modify the delay a bit using the approved AeroTech method to lower the M-delay from 10 seconds to about 8.)

Recovery:
The rocket preps quite easily and the 36" nylon parachute is adequate for recovery. Descent rate is reasonable, although a bit fast if you expect the rocket to land on concrete (which may cause the G10 fins to crack or chip). After two flights my Ariel still looks new except for some paint chips and mud from the last recovery in very soft and wet dirt. As with all PML kits, you will need to clean the inside of the tube after each flight to prevent the piston from sticking on the ejection residue that collects along the body tube.

Flight Rating: 5 out of 5

Summary:
This was my first PML kit and I specifically picked it because of many recommendations on it's choice as a Level 1 certification rocket. I concur--if you are looking to certify Level 1, then consider the Ariel. The pre-slotted Quantum Tube (QT) airframe with piston ejection and the Kwik-Switch motor mount are key PROs. I didn't really notice any key CONs, except that I would have preferred that the kit come supplied with D-links and maybe rail buttons instead of the 3/8" lugs.

Overall Rating: 5 out of 5

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