Page History

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1. 1. Assemble the nozzle. Add o-rings and lubricate well.
   2. Follow the 'MIT Rocket Team Grain Cutting and Bonding Procedure' to bond the grains to the liner, using the nozzle assembly as a placement guide. Apply aeropoxy to the splice, if any.
   3. Bolt the nozzle assembly to the case, taking account of directionality.
   4. Slide the motor load into the case.
   5. Use RTV to attach the insulation disk to the forward closure. 
   6. Attach the pressure transducer to the forward closure.
   7. Add o-rings to the forward closure and lubricate generously. Slide the closure into the open end of the case.
   8. Bolt the forward retention ring to the case.
      
      

2. Piston
   
   Hermes III Piston Assembly Procedures
   Materials
   

    

   •  

     Piston

   •  

     1/4 in torque wrench

   •  Integrated Firebolts
   •  Multimeter
   •  Teflon tape
   •  2 1/4 NPT plugs 
   •  Safety goggles
   •  Gloves
   •  Weigh boats 
   •  Popsicle sticks
   •  Elbow joint
   •  Tee fitting
   •  Adjustable wrench
   •  Vice grip/pliers
   •  Small scale
     
     

   Procedures

   1. Using a 1/4 inch torque wrench, ensure that the bolts holding the piston together are tight (100 inch-pounds of torque). If the bolts are loose, the piston will lose pressure as it extends. (torque wrench adapter in piston box)

   2. Use multimeter to check continuity of Firebolt (should be about 1.0-1.4 ohms) and twist the wires to short it. Two people should visually confirm that it is shorted. Wrap the Firebolt with five wraps of Teflon tape. Use the appropriate wrench to screw firebolt into the NPT plug.

   3. Everyone put on safety glasses. From now on, everyone within the vicinity of the pyrotechnics must wear safety glasses.

   4. Measure and pour 0.2 g of black powder into the other side of the plug, holding over a weigh boat to catch any fallout. This will probably be enough to completely fill the plug. Seal the opening by wrapping over the head and opening three times with Teflon tape. Make sure Teflon tape is flush on the inside.

   5. Repeat steps b-d

   6. Screw the plugs into the bottom and left sides of the tee fitting. Tap the tee fitting several times and make sure no black powder falls out after screwing in each plug. If there are any leaks, remove the responsible plug and re-make it.

   7. Compress the piston completely!

   8. Screw an elbow joint into a side female end of the tee after adding Teflon tape.

   9. Screw god nut on piston

   10. Slide diaphragm on, with anti rotation rod attached and slid through hole of anti rotation rod holder

   11. Screw eye nut on and line up with hole

   12. Put cotter pin in and bend ends

   13. Put gaff tape over cotter pin ends

   14. Pull piston up and tighten god nut with wrench (check that diaphragm doesn’t wobble)

   15. Wrench the elbow and tee assembly into the inlet hole of the piston with 5 wraps of Teflon tape until extremely tight and turned upright.

   16. Put the 2 assembled plugs into two remaining female ends of tee fitting

   17. Clock the tee fitting close to the body of the piston so the piston fits better into AV bay

   18. Test the piston by pulling up rod for 5 secs and checking that it is sealed
   19. Log Firebolts

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