Public Missiles MR-1

Public Missiles - MR-1

Contributed by Al Gloer

Construction Rating: starstarstarstar_borderstar_border
Flight Rating: starstarstarstarstar_border
Overall Rating: starstarstarstarstar_border
Manufacturer: Public Missiles

Brief:
A real short mid to high power sport flier styled after an anti-tank weapon. It's basically a big nose cone with just enough body to hold the fins. Available in both 29mm and 38mm, this review reflects a 38mm build.

Public Missiles, Ltd. MR-1

Construction:
The parts list:

  • 1 Nose cone with pre-attached shock cord
  • 1 Urethane nosecone transition with launch lug mount
  • 1 Body tube (available only in Quantum Tubing)
  • 1 Parts for 2.1" piston (tube, bulkhead, strap, D-ring
  • 3 G-10 fins
  • 2 Centering rings
  • 1 Launch lug
  • 1 Motor mount

This is a basic PML build. You need to make sure you sand all the epoxy points as the bond to QT can be difficult to attain. In the case of this review, I was building with the 38mm mount so the internal fillets were a challenge at best (not a lot of room to work). I mixed up a slurry of 6 minute epoxy and milled fiberglass and then injected it into place holding the rocket level. I repeated this three times and got a fairly good set of internal fillets. In the case of this rocket, larger fillets on the outside are called for strengthening purposes.

Because the base of the nose is almost twice as wide as the body tube, the transition has a molded riser for the launch lug. This is not a bad case of flashing so read the directions and don't grind it off! I found that basic hobby epoxy did a lousy job of holding the brass lug to the urethane transition. JB-Weld is strongly recommended. If you are a hardcore rail junkie, this one will put you to the test of your creativity. Also, note that when finished, the nose cone does not seem to fit right and there is a 1" band exposed. This is there by design.

Retention is difficult as the gap between the MMT and BT is about 1/2". I epoxied a SHCS in and use a single nut to hold the motor in. If ever a rocket called for an Aero Pack or Slimline retainer, this is the one.

Finishing:
I painted the body gloss black, the nose red, the transition blue and covered the funny step in the nose with chrome trim Monokote. Other than that it's a basic paint your rocket if you like job. Of course with the airframe being QT, you need to give a light sanding for best paint adhesion.

Construction Rating: 3 out of 5

Public Missiles, Ltd. MR-1

Flight:
Stuffing in the recovery system is a bit of a challenge as there just is not a whole lot of room. You push the piston as far back as possible, fold the chute real tight, and poke it in to the body as best as possible. Then invert the NC, stuff everything else in there, and slip it all together.

The first flight was at METRA on Aug 6th, 2006. The load was a G67R in the 38-120 casing. The rocket took off almost sideways off the pad and never got more than 150' off the ground. I heard the deployment charge, however, since it was basically a ballistic trajectory, the forces involved got in the way of the deployment. One of the fins had broken away intact. The cause of the wild flight was obvious. On launch, the lug had torn away and the rocket lifted off unguided.

The post repair second flight was at CATO on August 19th, 2006. The load this time was a G61 in the 38-120. A near perfect flight!

Recovery:
This is a standard PML piston design system. Some will choose to leave out the piston, however, that is a matter of personal choice. This is a perfect rocket on a small field for the 1 grain 38mm reload and on a larger field for the 2-grain. It is rather short and using electronics might me iffy. This might be a perfect airframe for the new AT EFC product if you wanted.

Flight Rating: 4 out of 5

Summary:
Were I to build this again, I would slot the body to the base and assemble the fin can outside the body allowing for the better fin to MMT.

PROs:

  • Typical easy to build PML kit.
  • Nice flight profile

CONs:

  • Not the best candidate for a rail.
  • Stuffing in the laundry required more thought than I like on the field.

Overall Rating: 4 out of 5

Other Reviews
  • Public Missiles MR-1 By John Lee (June 14, 2009)

    The MR-1 is something that looks like it comes out of an ordnance inventory. Opening the bag, that impression is confirmed as one looks at the parts. The Quantum tubing and glass fins make this a heavy and substantial rocket. The NC makes it even more so. I am hoping to get a chance to do some HPR flying in May at the West Texas Thunder event so I started looking through some of the bigger ...

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