1/2A3-4T Model Rocket Engines (4)

This is a 1/2A-class 1/2A3-4T single use mini model rocket engine from Estes. For use in single stage model rockets.

Estes 1/2A3-4T Model Rocket Engines (4) Mini Rocket Motor #1504
 Estes Rockets # est1504
Retail $11.29  SAVE 21% !
Estes Rockets Item # est1504
Specifications :
  • Length: 1 3/4"
  • Diameter: 1/2"
  • Estes Product Number: 1504
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Spotlight Review

"Great Kid Friendly Motor"
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.

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  • "Mini" class model rocket engine 4 pack.
  • Single stage model rocket motor.
  • Detailed instructions.
  • Easy to use.
  • National Association of Rocketry certified.


  • Length: 1 3/4"
  • Diameter: 1/2"
  • Estes Product Number: 1504


  • 4 1/2 A3-4T Model Rocket Engines
  • 4 Igniters
  • 4 Plugs

Requirements & Suggestions

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  • WARNING: Model rocket motors are flammable. Please use caution.
  • Must be 14 to purchase in CA and NJ.
  • Do not burn engines.
  • Soak in water to destroy.

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