Brief:
This is a rocket designed to fly to extreme altitude if desired. It has a 1.6" diameter and is 44" tall with a payload bay and solid resin nose cone. It can be flown with 38mm motors; or 29mm motors with an adapter. Everything that normally comes with a PML phenolic kit is provided including a piston ejection system, parachute, and fiberglass fins. A 29/38 adapter is not provided, nor are any motor retention or nose cone retention methods or parts provided. Since this rocket can conceivably go very fast and high, one item not normally provided with PML kits but provided with this one is fiberglass cloth for stronger fin attachment. The finished weight of the rocket with a simple phenolic adapter and all retention hardware is 21oz. without a motor.

Prize Notification/Delivery:
This kit was provided as a prize from a periodic random drawing sponsored by EMRR, and donated by Rocket Silo. Upon notification that I was the winner, Rocket Silo very quickly responded, and had PML drop ship the kit directly to my home. I received it within a few days. I thank them profusely for their rapid response and generosity. I would not have chosen this kit myself because I was intimidated by the high altitude design (the fields in Minnesota do not support real long walks). However, it stretched me to learn how to fiberglass for the first time, gave me my first high power payload rocket (now I will have to buy an altimeter), and by necessity led me to find a source of high quality motor retention for all my rockets.

Construction:
Construction of this rocket is very straightforward as is typical with PML kits. The method for fiberglassing the fin area was described adequately, and I experienced no problems. However, I had to wait to do this step till after I had designed, purchased, and installed motor retention hardware.

Since this is a minimum diameter rocket, the usual engine retention methods of blind nuts and clips can not be installed. I decided to try two different methods, with this rocket being a test bed for both. One method would be to epoxy a piece of small threaded rod to the outside of the body tube, and use a nut and washer to retain either a 29/38mm adapter or a 38mm motor case. The fiberglass would then be applied over the top of this threaded rod for extra strength. The second method is to install a clip specifically designed for minimum diameter high power rockets, and for sale through SarahzRocketry (link-out dead). I highly recommend this hardware, as it is designed to exactly fit this application. The only problem I encountered was that the 29/38mm adapter I purchased had a longer than standard thrust ring. So the brass clip that retained a 38mm motor case would not fit over the thrust ring of the adapter. I wrote SarahzRocketry, explained the problem, and they were gracious enough to make a second brass clip that exactly fit over the end of my adapter. The MD-1 hardware normally includes a brass retainer clip sized for standard RMS motors, a stainless steel machine screw, a threaded mounting flange and installation instructions. The web site also has detailed installation instructions with lots of pictures. They probably had to make tooling capable of making this second custom brass clip, so if others buy this kit and also buy the adapter I did, it should be easy to include both brass clips at the same time if you ask. The adapter was purchased from Red Arrow Hobbies in Michigan over the Internet. I purchased this particular adapter because it was $8.00 and included both a thrust ring and motor retention.

The other problem I encountered was nose cone retention. After irreplaceably losing the original nose cone off my vintage Estes SAROS several years ago because it was not firmly enough attached to the payload tube, I am particularly sensitive to this issue. Normally, with a hollow plastic nose cone, this would not be difficult. The PML instructions say "Now install the nose cone atop the rocket and secure it in place using small screws or rivets.", which would be easy to do with a hollow nose cone. However, this nose cone is solid resin, and you wouldn't want to trust screw holes tapped in the relatively soft resin to stand up to repeated launches and recovery. So I found some small 4mm machine screws and compatible steel nuts at Home Depot. Holding the nose cone firmly in the payload tube, I drilled two 5/32" holes through the phenolic body tube into the nose cone shoulder about 1/2" deep. These two holes are about 5/8" back from the front of the tube. Using the 5/32" holes as pilot holes, I then carefully drilled two 5/16" holes 1/4" deep into the nose cone shoulder after I removed it from the body tube. Caution must be exercised with this step because steel bits dig deep fast into resin. I goofed and went too deep the first time and had to rotate 90 degrees and try again. I CA'd and then epoxied the nuts into those holes. I used the machine screws to simultaneously keep glue out of the threads of the nut and keep the nuts lined up vertically, but also being careful to not permanently glue the screws into the nuts. This was a dicey operation as I kept turning the screws in and out of the nuts until the glue had cured.

One other minor deviation from the kit was to elevate the brass launch lug off the rocket body by use of a wooden popsicle stick. I did this so that launch rod friction would not mar the finish or otherwise rub against the body during takeoff. I used a little leftover fiberglass cloth to cover the front and back of the popsicle stick, and used plenty of epoxy to fillet the sides of the assembly. It took quite a bit of epoxy and putty, but it looks nice and streamlined, yet raised off the body some.

Finishing:
Since this rocket apparently only comes with phenolic tube rather than the new quantum tube, finishing involves quite a bit of work with putty to fill in the spiral grooves. The body tube is essentially 38mm engine mount tubing. The transition to the fin area that had fiberglass also required quite a bit of sanding and filling to smooth it out as much as possible. The 20 minute finishing epoxy used on top of the fiberglass as recommended by the instructions is quite a bit easier to sand than regular 30 minute epoxy. A coat of primer revealed spots requiring more putty, and the final paint coat was Krylon teal, which goes well with the dark blue and red decal.

Construction Rating: 4 out of 5

Flight:
The first flight was with a 29mm F40-4W reload. The rocket flew straight up to about 1000 feet, and deployed the cute at apogee. The second and third flights were also hot, straight and normal with an F and a G.

Recovery:
At the time of the first flight, I did not have the brass clip from SarahzRocketry and only had the single threaded rod and nut to retain the adapter/motor casing. The small threaded rod was not hefty enough and bent out of the way to allow the adapter and motor to eject out the back when the ejection charge fired. Fortunately, there was enough gas pressure buildup to also eject the parachute. The adapter and RMS casing were found by a spectator, and returned promptly. The lesson here is if you can bend a threaded rod with your fingers, it is not strong enough to retain a motor. The other lesson is to use the hardware obtained from SarahzRocketry. It is very strong and works great, as demonstrated during the second and third flights. The parachute is a little small for a 21-oz. rocket, but I am sure that PML downsized a little out of concern about how high it would be coming down from if used with an H or bigger engine.

Flight Rating: 5 out of 5

Summary:
PRO: Strong PML materials and design. The solid resin nose cone provides plenty of CG shift forward for bigger motors. CON: No provision for motor and nose cone retention. 29/38 adapter not included.

I understand PML's philosophy on not providing motor retention with their kits as many modelers have many different preferred methods and hardware. However, this is a minimum diameter rocket and most modelers' preferred methods and hardware are not appropriate on this rocket anyway. Since this is a rocket that will not normally be flown with a 38mm motor unless someone regularly launches at large recovery areas, I feel that PML should also include an adapter with the kit. I STRONGLY urge PML to include a simple 29/38 adapter (like the one I bought) and minimum diameter retention hardware for both a 38mm motor and a 29/38mm adapter. In fact, they should subcontract this to SarahzRocketry, where I obtained the hardware used on this kit. Since this is the only rocket made by PML (that I know of) that has a solid nose cone on a payload section, I also urge PML to include a method for nose cone retention, as normal nose cone retention methods are not applicable either. The rocket itself is a great addition to my fleet. It flies well, and the payload bay is large enough for an RRC altimeter.

Overall Rating: 4 out of 5