At first blush it may seem un-economical to buy a 1/2A motor given that I am usually stuffing something a lot bigger in my rockets, but I really love these little motors. One of the key elements to their disproportionate performance is their weight. An 18 mm 'A' motor is the same size as a 'C' motor which holds 4 times the propellant. The 13 mm motor case for the mini-size motors are there fore much less than 1/2 the weight of their bigger brethren. In large rockets, this may not make a big difference in the overall launch weight, but in small 13mm and 18mm rockets with balsa nosecones and fins, the motor makes up a much larger percentage of the rocket launch weight. This little motor will send my 18mm scratch built as high as a full 18mm A' motor will. In minimum size 13mm rockets, which are really fun to build, this motor will send them almost out of sight. I always make sure I have plenty of mini motors on hand in both this and full A sizes. They are very economical and a good way to teach small hands how to install and prepare motors in small rockets that stay within eye shot for easy recovery.

Not bad for a small motor. No problems at all with these engines.