The Pratt Hobbies Positron is a small rocket designed to be a 'recoverable' Mosquito (well actually an Astron Streak, the 18mm version of the Mosquito). To achieve this it uses an ejectable motor holder and Nomex® streamer, tied to the rocket body by a Kevlar® line. The kit is complete, and actually comes two to the package. The fins are precut balsa and attach easily to the body tube. The light, plastic nose cone is attached to a shoulder piece of tubing and then glued into the body tube. The shock cord is attached to this shoulder and to the thrust ring in the motor holder tube.  

I built this kit in about 30 minutes, not including glue fillet drying time. We painted the first Positron yellow with a silver nose and ring around the motor holder. The swept-back fins achieve the 'retro' look that Doug Pratt was looking for. I rate the kit 5 points (mainly because there were two models in the same bag) and the construction 4 ½ points (I may have added a wrap around fin positioner).  

The recommended motors for the Positron are a 1/2A6-2 and an A8-3. So far we have only launched with the 1/2A6. The Positron leaps off the pad, even with a 1/2A6, I can't imagine you would ever find the Positron with a B or C motor. Flight was very stable and quite high. The motor holder ejects well and deploys the Nomex® streamer. The streamer is quite short and doesn't slow the rocket down that much. This one would probably fly well in fairly high wind. After you get the rocket back, it is only moments until you can fly again (no parachute or wadding to worry about. )I rate the flight performance 5 points, but the recovery 4 points (the streamer is a bit too short). It is still really fun to fly.  

I would rate this rocket 4 ½ points overall. The only thing I would change is the streamer, but even that's not bad at all. Thanks for a nice rocket, Doug.  

One of the reasons I purchased this kit was because you get two of them.   One for me, and one for my son Jamie. Another reason was because we lost a really nice little Estes Quark on its second flight, almost lost an Estes Mosquito on its first, and I thought a streamer recoverable cute little rocket would be the answer. I also thought Doug Pratt's use of Kevlar® only (for shock cord)
and Nomex® (for reusable heat shield) were innovative (at least in terms of what I'd been exposed to previously) and desirable.

Construction

I ordered a few kits at the same time, so all the kits were shipped in heavy-duty prism shaped priority mail boxes. I knew there was no chance of damage even before opening the boxes. All the parts for both Positron kits come in the same heat-sealed plastic bag.   I read through the instructions and they seemed pretty straightforward and easy to follow.

The instructions recommend using white glue for construction.   I happened to have some yellow glue from woodworking, and some USA Gold CA I purchased in the same order, so I used these. I used the CA on paper to plastic joints (like body tube to nose cone), and for reinforcing body tube edges where they might be stressed by the Kevlar® shock cord, and the tips of the fins because I faired them to a more fragile profile than the kit provides. Compare my pictures with those in the review provided by Mike Rangitsch. Using CA was probably unnecessary, but I just couldn't resist using my new stuff.

The fins on all of Pratt's kits are laser cut. I think this is a really nice feature, especially with the curved leading edge of the Positron's fins.

One of the things I'd like to see added to the instructions is a suggestion to mark the body tube where the root and leading edge of the fins should make contact. The angle between the root and the trailing edge is very shallow, so it's difficult to tell from looking at the bottom of the body tube whether or not the fin is positioned properly along the length of the body tube. My son's fins had to be removed and reattached because all three where at different locations, and one was significantly higher (1/8") than the others, causing the rocket to appear lopsided. A wrap around fin placement guide of the correct width would be perfect.

The Nomex® streamer material seems to unravel along the edges rather easily. I don't know how long it would be before it unraveled to unusable state, but I found myself thinking about how to reinforce the edges. If it does continue to unravel, I'll probably ask my wife to sewa stitch along the edges.

I would rate the construction at 4 points. Complete, and easy and quick to put together.

Flight

The motor mounts in a motor mount attached by a Kevlar® shock cord to the coupler between the nose cone and the main body tube. There is a Nomex® streamer between the two. The instructions call for rolling up the streamer, inserting it into the top of the motor mount thrust ring, and then looping the Kevlar® and inserting it into the rocket body.   I found this really hard to do, as the Kevlar® doesn't like to remain looped or coiled. What I found worked very well was folding the Nomex® streamer back and forth (instead of rolling it) and then looping the Kevlar® shock cord around the Nomex®. In my static tests of popping out the motor mount, everything seemed to uncoil and unfold
without problem.

First flight (and only flight so far) was rather eventful.   Friction fit a ½ A6-3 into the motor mount and over and above the instructions taped the motor at the bottom to the motor mount. Flight was perfect with the ½ A motor. Nosed over beautifully at apogee and then dove right for the ground. Turned out the motor ejected, but not the motor mount, so it did exactly what my Estes Quark did. The motor mount must have had a tighter fit than the motor itself, though I really didn't think it did. I'm used to permanently mounted motor mounts with clips, so I have some self-education ahead of me. I would have attempted to try again, but one of the fins came loose and I didn't have any CA with me. I might try using an A motor, but I really like this rocket and don't want to lose it. I'm looking forward to flying this rocket a lot.

I rate the flight experience: 4 points. It would have been a 5 had everything worked perfectly.

Overall

Overall I really liked this kit. The quality of the components is good, the instructions are clear, and I like having a cute little rocket that I can actually find after launching. It would be nice if the Nomex® streamer came with an edge that didn't deteriorate. It also would have been nice if the first flight went perfectly. I really like to see small manufacturers in the business. Let's support them!

Overall rating is 4 points.