Estes Rocket Motors - 1/4A3-3T (Pack4)

The Estes 1/4A3-3T is a mini model rocket engine designed for flights in lightweight rockets. Supplied here as a bulk pack of 72, this listing uses Estes part D-ES1502 and the 1/4A3-3T specification to deliver quick boosts with a 3 second delay for ejection. The compact 13 mm format keeps overall mass down while providing reliable performance for small models within the stated lift limits.

Each retail 1/4A3-3T pack is a set of mini engines intended for single-stage use, offering consistent ignition and predictable delay timing. The figures below summarise the manufacturer-provided specifications for the 1/4A3-3T motor.

What's Included (Per Retail Pack)

• 4 engines
• 4 starters
• 4 starter plugs

Specifications

• Motor Type: 1/4A3-3T mini model rocket engine (single stage)
• Length: 1.75 in (4.4 cm)
• Diameter: 0.50 in (13 mm)
• Estimated Weight: 0.21 oz (6 g)
• Total Impulse: 0.625 N-sec
• Time Delay: 3 seconds
• Estimated Max Lift Weight: 1.0 oz (28 g)
• Max Thrust: 4.90 N (1.1 lb)
• Thrust Duration: 0.25 seconds
• Initial Weight: 0.21 oz (5.9 g)
• Propellant Weight: 0.05 oz (1.3 g)
• Quantity Per Pack: 4

Estes 1/4A3-3T motors are intended for lightweight models within the stated lift weight and are part of the 13 mm mini engine range. The combination of quick thrust and short burn makes them suitable for small, single-stage flights where a modest total impulse and defined delay are required.