Brief:
The USR Miniroc 1.2 is a small 29mm minimum diameter rocket. It is a 3FNC style rocket with swept fins and overall a fairly attractive profile. It should be able to fly on anything from C to G power and USR suggests flying it on an H motor as well. The rocket is very stout, considering the light weight and small size.

Construction:
The kit came with 4 pages of adequate but limited instructions giving useful diagrams and details on construction and flying. The instructions also suggest that the Miniroc 1.2 might be good for egg loft and flexwing competition events. The manufacturer did not, I think, adequately edit individual sets of instructions.

After going over the parts list in the instructions, I discovered the kit was missing three parts--1 of 2 body tube couplers (CT-11-9-2), 1 shock cord (SC-5), and 1 streamer (SM-3). This was the first time that I had purchased a kit with parts were missing, and as a result I was suspicious that somehow I had lost these parts when I opened the kit. The rocket uses a balsa nosecone and 3 nicely cut plywood fins that appeared to be of good quality but one was warped. All other components appeared to be in good shape. Despite the missing parts and warped fin, I decided to proceed with building although these two factors reduced my enthusiasm for USR kits. I elected not to contact USR to discuss these failings.

I built the rocket per the instructions except using 5-minute epoxy throughout construction. I tapered the fin edges as described and used my Estes fin alignment guide for fin installation. This is a minimal diameter rocket and the instructions suggested surface mounted fins. I think that this should be fine. After tacking the fins in place with epoxy, I gave them a nice fillet. I cut the ¼ inch launch lug on an angle as suggested and gave the lugs a fillet as well.

For construction of the upper payload section of the rocket, the instructions say to glue the payload plate into the payload tube with the beveled side forward. The plate did have a crudely beveled edge that was ragged, but this method of installation was irrelevant considering that the plate needed to be sanded down to about ¾ of its original diameter just to fit in the tube. By that point the beveled outer edge was long gone.

The recovery system calls for a ¼" elastic shock cord to be glued into the main body tube using the 3-fold paper method. I installed it as described, using 6 feet of ¼" elastic shock cord that I had lying around.

I could not build the 24mm motor adapter as described since the coupler tube intended for this purpose was missing. When needed, I used a different one that I had on hand.

PROs: The kit parts are stout. Construction is straight forward and should be suitable for a beginner if it weren't for some of the failings of the kit.

CONs: The kit had 3 missing parts that cost me a couple of bucks to replace. One fin was warped. The instructions are cobbled together from those of other kits and not properly edited. The payload bulkhead plate did not fit properly.

Finishing:
I did not fill the grain of the balsa nose cone. After painting, it was fairly smooth. I think I would use a plastic nose come if I were designing this kit. The body tubes were very smooth so I did not consider filling spirals. I sprayed the rocket with a single, thin coat of automotive primer, gave it a brief sanding, then added a single coat of "hammered gray" automotive spray paint. I then used masking tape to add stripes with single coats of red and blue "hammered-look" paint.

The finished rocket weighed 106 grams (without a 24mm motor adapter). I substituted 5-minute epoxy for construction throughout instead of the recommended yellow wood glue, perhaps adding a few grams. The final weight listed on the kit pack is 40 grams and the USR web page lists final weight at 40 grams also. I found this to be ludicrous. I was suspicious of this before construction, so I weighed some of the components as I was building. For example, the screw eye (part SE-1), small plywood bulkhead (payload plate PP-11), and 6-inch airframe tube for the payload section (part B-11-6) together weighed 26 grams before gluing them together. I did not note the weight of all other parts, but considering that the payload section (which is ½ the length of the lower body) together with the streamer (11 grams) weighed 37 grams before construction, I don't see how it is possible for this kit to be built at the manufacturer's claimed weight. I feel that if I had been extremely conservative in my use of glue and paint, I might have been able to finish this rocket at 90 grams. USR should reevaluate its weight estimates. I think that a better value can be found in kits from other manufacturers.

PROs: Painting was a snap. I chose not to follow USR recommended color scheme which is hard to visualize given that USR shows only black and white drawings and/or photos of their rockets on their website. The instructions only include line drawings of the rockets. I typically do not adhere to manufacturer's recommended schemes anyway.

CONs: I chose not to apply the USR decals that came with the kit. They are less decal and more simply label, giving the name of the rocket. They do not appear to me to be the sort of thing you would add to a rocket if you were really interested in dressing it up, however, the decals might be useful to have in the event of a judging competition to remind people of the name of the rocket. The final weight of the rocket as described by USR is impossibly low.

Construction Rating: 1 out of 5

Flight:
I flew Miniroc 1.2 on a D12-7. I used 6 sheets of Estes paper wadding and packed the streamer as I normally would. This amount of wadding was very substantial, given that one has only about 9 inches of 29mm tubing into which to fit everything. One wrap of masking tape provided a good fit of the payload section coupler to the lower body tube. I added 2 wraps of masking tape to the nosecone shoulder to give a very tight fit, as I did not want to glue it in nor lose the nosecone. My son added 1/8 of a saltine cracker and my daughter added a single red desert flower in the payload section. These were meant as gifts to any aliens that might happen upon the rocket in flight.

The boost was to quite a nice altitude. Ejection was at apogee. The motor was kicked out and the shock cord burned through right at the glue point. The streamer gave good fast recovery to the payload section, while the main body tube plunged straight down. The body tube took a 3 inch core sample of the desert dirt and the rocket remained in the upside-down, stuck-in-the-ground position. Upon inspection, the rocket suffered essentially no damage other than the failed shock cord. This is a testament to the rugged nature of the tubing that USR supplies with the kit.

Recovery:
The shock cord system clearly wants for some sort of a Kevlar® leader cord. The 3-fold paper glue-in method should still work fine though. I used 6 feet of shock cord but this is probably the minimum required in order to avoid body tube dings.

Flight Rating: 3 out of 5

Summary:
The Miniroc 1.2 flies nicely and is built of rugged stock. Despite this, I gave the rocket a low rating because of the missing parts that typified my experience with USR. The overall shoddy nature of the kit components and instructions I think represents this kit as a poor value.

Overall Rating: 2 out of 5