Introduction:
This piston test is conducted to qualify and test the separation mechanism without the dependencies and difficulties of a full ground test. 

Overview:
The mission package minus the nose cone is brought to the blast chamber. Where the nose cone would be there is a plywood base, and the safety coupler is tied from the ceiling with a rope to keep it from hitting the ground.
Person leading the test MUST have black powder handling form filed with the ATF. There must be AT LEAST 2 people at the test.
Tests:
10/31/2018: 0.2g black powder, no shear pins

Materials:
  • Scale with .01g resolution (Accurate within +- .03 g)
  • Multimeter
  • Firebolts
  • Black Powder
  • Weigh Boats and popsicle sticks 
  • Gloves
  • Screwdrivers
  • Teflon tape
  • Safety glasses
  • Bolts/screws
  • Piston
  • Tubes
  • Bulkheads
  • Plywood Base Plate
  • Webbing (for securing test setup in blast chamber)
  • Battery
  • Extension Chord
  • Wrench (for holding Firebolt while filling)
  • Scissors

Piston Integration Procedure:
  1. Using a 1/4 inch torque wrench, ensure that the bolts holding the piston together are very very tight. If the bolts are loose, the piston will loose pressure as it extends.
  2. Check continuity of Firebolt (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 pliers 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 safey glasses. 

  4. Measure out the appropriate amount of black powder into a weigh boat (will vary over testing matrix) and pour it into the other side of the tee  , holding over a weigh boat. Seal the opening by wrapping over the head and opening three times with teflon tape.

  5. Compress the piston.

  6. Screw an elbow joint into a side female end of the tee.

  7. Wrench the elbow and tee assembly into the inlet hole of the piston with 5 wraps of teflon tape until extremely tight.

  8. Screw a 1/4 NPT plug into a female end of a 1/4 NPT tee adapter.

  9. Seal the open female end of the tee fitting with a plug.

Integrate the AV coupler following the Hermes Integration Procedure.

Test Setup Procedure:

  1. Place the diaphragm in the cup. Screw in the holes with 10/32 set screws.
  2. Secure the diaphragm to the piston using an eyebolt
  3. Secure the payload bulkhead to the nose cone coupler using the 3 alignment holes and chamfered screws.
  4. Secure the coupler to the mission package tube using 6 screws.
  5. Secure the piston to the payload bulkhead using 4 screws into the base of the piston.
  6. Ensure (doubly, triply, as many times as necessary) that the cup slides smoothly (aka the piston is pointed straight up in the mission package tube.)
  7. Attach the packaged drogue to the eyebolt.
  8. Constrain the forward retention ring
  9. Insert the forward retention ring into the mission package tube.
  10. Insert shear pins
  11. Clear stray objects from the blast chamber
  12. Test the resistance of the firebolt and log it
  13. Run detonation wires out of the blast chamber and close the door
  14. Connect a voltage source to the wires and detonate the black powder.
  15. If a misfire occurs, wait outside the chamber for one minute. Verbally and visually confirm that the power source is disconnected to the igniter wires before reentering.

Disassembly:

  1. In a well ventilated area, remove the pyrotechnic assemblies from the piston. 
    1. It will smell really bad (sulfur smell =/= good)
    2. Very slowly loosen the pyrotechnics
  2. Unscrew the plug slowly to let it vent. 
Item
No.
Description
Item
No.
Description
1Front Head19 **Retaining Ring
2 **Bushing20Tie Rod Nuts (4)
3 **Wiper21Lock Washers (4)
4 **Bushing O-ring22Tie Rods (4)
5 **Bearing Strip23Cushion Adjustment Screw Nut
6 **Rod U-Cup24Cushion Adjustment Screw
7Cylinder Tube25O-Ring
8 *Piston Retainer26Cylinder Insert
9Piston27 **Cushion Poppet
10 **Piston U-Cup28 **Front Cushion Spring
11 **Rear Cushion Spring29 *O-Ring
12Cylinder Insert30 **Piston Bearing
13 **Cushion Poppet31 *Piston Lock Nut
14 **Cylinder Tube Seal32 *Threaded Washer
15Rear Head33Cushion Adjustment Screw Nut
16Retaining Ring34Cushion Adjustment Screw
17 *Piston Rod35O-Ring
18Jam Nut  

Assembly:

The top is the cap with the hole.

http://www.motioncontrolsllc.com/sites/default/files/product-datasheets/D-Series-Datasheet.pdf

http://www.motioncontrolsllc.com/accessory/d-series-maintenance

Seal repair kit: McMaster P/N 6491K136

  1. Place the O-rings for the cap and base into the cap and base. 
  2. Following the instructions for the second link, reassemble the piston.
  3. Tighten the tie rods to 100 inch-pounds.
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