Objectives:
- Relate black powder mass to piston force
- Demonstrate ability to consistently break shear pins
Future Goals:
- Test with realistic package (nosecone + cup)
To Do:
- Build piston testing rig
- Find way to measure force
- Consider using nitrocellulose instead of black powder
Piston Testing Rig:
- Essentially the middle part of Hermes bolted on to a plate
- Use Hermes body tube (need to find where this is)
- From top to bottom:
- Motor coupler
- Hermes body tube
- Cup
- Avionics Bulkhead
- Nosecone Coupler
- Bulkhead
- Base Plate
Pressure sensitive film adapter:
- 2 Pieces of inch round stock
- Lathe and tap hole for piston rod (3/8-16)
Numbers:
- Shear pins require approx. 75lbs to break each, but vary greatly (75-115 lbs)
- Avionics bulkhead rated to 500lbs (see relevant wiki page), but survived up to 1g of bp
- Piston pressure rated to 8000 pounds
- Typically use 0.2g of black powder, equivalent to ~400 lbs of force from black powder calculator