PVS-14 Focus Cap

3D-printable flip cap for a PVS-14 night vision monocular.

This is a replacement cap with a rotating aperture disc for a Butler Creek 09A scope cap. The disc has three aperture sizes plus a closed position, allowing you to adjust depth of field without removing the cap. The closed position also helps protect the lens and tube.

Features:

• Fits a PVS-14 objective lens using a Butler Creek 09A scope cap body

• Rotating aperture disc with multiple aperture sizes

• Closed position for lens and tube protection

• Detent mechanism for positive aperture positions

• Uses common small hardware

Required parts:

• 3D printed cap insert

• 3D printed aperture ring

• 1x AR-15 detent spring, cut in half

• 1x M3x4 countersunk screw

• 1x 3/32" ball bearing

• 1x Butler Creek 09A flip-open scope cap

Printing:
Print both parts face up. The main body will need supports.

After printing, check that the aperture ring rotates smoothly, the screw seats cleanly, the detent spring hole is clear, and the ball bearing can move freely in the detent pocket.

Assembly:

1. Insert the cut detent spring into the small hole in the printed cap insert.

2. Place the 3/32" ball bearing on top of the spring.

3. Carefully place the aperture ring into position, capturing the spring and ball bearing.

4. Fasten the aperture ring with the M3x4 countersunk screw.

5. Verify that the ring rotates and clicks into each aperture position.

Installing on the Butler Creek cap:

1. Remove the hinge pin from the Butler Creek 09A cap.

2. Remove and discard the factory flip-open door.

3. Place the printed flip cap assembly into the hinge.

4. Reinsert the hinge pin.

5. Check that the cap opens, closes, and rotates freely.

Notes:
Make sure the aperture ring has positive detent engagement and cannot rotate freely under light handling. If the ring is loose, the detent may not work reliably.

Do not overtighten the M3 screw. The aperture ring should be retained securely while still rotating smoothly.