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Motor Selection

Kit Guidance

From kit packaging (IMG_7727):

  • Requires 38mm diameter rocket motors
  • Use H, I or J power motors, as well as high thrust G motors

Typical altitudes per packaging:

Motor Class Altitude Range
G motors 300-500 ft (requires avg thrust ≥80N)
H motors 600-1700 ft
I motors 1700-3500 ft
J motors 3700-6100 ft

Selected Motor

AeroTech H128W-14A - purchased locally in Sweden from Tripoli members.

See Motor Procurement for why this is the only practical option.

Specifications

Parameter Value
Diameter 29mm (reload)
Total Impulse 172.9 N·s
Max Thrust 168.7 N
Average Thrust 128 N
Burn Time 1.3 s
Delay 14 s (adjustable)
Propellant White Lightning (W)
Motor Length 194 mm
Total Mass 215 g
Propellant Mass 93.6 g

Hardware Required

The H128W is a reload motor requiring:

  • AeroTech 29/180 Case (PN: 60010)
  • 29mm forward closure
  • 29mm aft closure

Adapter Required

Peregrine has 38mm motor mount. H128W is 29mm.

Solution: 3D printed clamshell adapter from Thingiverse Thing:5971997

Parameter Value
Design Clamshell (two halves)
Material Translucent PETG
Printer Bambu Lab P1S

Material Choice

PETG instead of ASA because P1S lacks chamber heating. Tall ASA prints fail (spaghetti) after reaching certain height without enclosure temperature control.

Safety

Based on AeroTech Safety Data Sheet:

Hazard Classification

H128W propellant mass is 93.6g, classified as Explosive 1.3C (>62.5g propellant).

Handling

  • No smoking within 25 ft (7.6m)
  • Keep away from open flames and heat sources
  • Store in dry location, away from acids
  • Keep in original packaging until ready for use
  • Do not use indoors

Combustion Products

White Lightning propellant produces:

  • Hydrogen Chloride (HCl)
  • Carbon Monoxide (CO)

Do not breathe exhaust fumes.

Physical Properties

  • Auto-ignition temperature: 550°F (288°C)
  • Propellant density: 0.058-0.065 lb/in³

First Aid

  • Inhalation: Move to fresh air, call physician if symptoms persist
  • Skin contact: Wash immediately
  • Burns: Immerse in cold water, seek medical attention for severe burns
  • Ingestion: Induce vomiting, call physician

Fire Fighting

Use water only. Foam and CO2 are ineffective. Motors may become propulsive in fire.

Disposal

Do not dispose in landfill or sewer. Burn in controlled manner: bury motor with only nozzle exposed, ignite electrically from safe distance.

EU P2 Pyrotechnics Regulation

H-class motors are P2 category under EU Directive 2013/29/EU.

Per TTJA (Estonian Technical Regulatory Authority): Each EU member state determines P2 handling rules internally. In Estonia, the equipment producer should provide adequate training, which forms the basis for professional P2 device handling.

Training Adequacy

Whether reading the AeroTech SDS constitutes adequate "producer training" for Estonian P2 compliance is unclear. This is one reason for flying in Sweden where the regulatory framework is established.

Reference

Apogee product page lists compatible motors: Peregrine on Apogee Rockets

Note: Most motors listed there are not available for purchase in Estonia/Europe. The H128W was selected based on what Swedish Tripoli members can provide locally.