Drilling Holes for Externally Adjustable Bellows

Applicable for: Both PBN and tantalum externally adjustable shutters

Materials Needed

• Paper kimwipe

• Ultra clean foil

• Kapton tape

• Clean gloves and hardware

• TiN or cobalt-coated drill bits (centering and number 43 bit)

• Number 2 bolt and corresponding washer

Procedure

1. Preparation:

• Wrap the Bellows:

  • Fold a paper kimwipe into a square and cut toward the middle. This will be used to absorb any excess oil from the machining process.

  • Slide the bellows rod to the center of the kimwipe cut and let the kimwipe rest flush with the bellows flange.

  • Cover the kimwipe with ultra clean foil, poking a hole and sliding it down the bellows rod.

  • Compress the bellows completely and evenly, then wrap the rest of the bellows (leaving about half of the threading exposed) with foil.

  • Have one person hold the bellows compressed while a second person secures the bellows in a compressed state using kapton tape.

2. Assembly:

• Assemble the shutter and bellows with the collar in place, inserting the shutter blade into the bellows assembly. Ensure the collar loosely hugs the assembly near the strain-relief hole.

• Orient the shutter blade, collar, and strain-relief hole so that the strain-relief hole faces the same direction as the shutter blade. The collar should be orthogonal to the strain-relief hole.

• Tighten the collar near the tip of the bellows assembly to provide maximum room for drilling later.

• Wrap the shutter blade and most of the rod with clean foil, leaving a little exposed for drilling.

3. Drilling Setup:

• Machine Shop Preparation:

  • Set up the drill press stage.

  • Insert a centering drill bit (preferably TiN or cobalt-coated) into the drill press. Ensure it is secure and not wobbly by turning on the drill briefly.

  • Find and insert a number 43 bit, suitable for a number 2 bolt.

• Drilling:

  • Secure the shutter and bellows ensuring the rod is level and the drill will contact perpendicular to the rod.

  • Drill a starter hole with the centering drill bit, supporting the rod with a finger to keep it level (note: the rod may get warm).

  • Be mindful of the bellows flexing under the force. Support the female collar during drilling.

  • Switch to the number 43 bit and complete the drilling.

  • Test the hole with a number 2 bolt.

4. Cleaning and Finishing:

• Ultra clean the machined parts including the bellows, shutter rod, and collar.

• Suspend the bellows and shutter rod over treatment containers, keeping the foil coverings on until the end.

• After cleaning and drying, keep the shutter and rod together as they form a unique pair due to the drilled angle.

Updates

• JAM ordered new drill bits and centering bits in January 2022, which should be available in the PL lab.