Needle Plate Locating Plunger 82171 - Alignment Pin

Part Number: 82171

Type: Needle plate locating plunger / release pin

Related Parts: Works with Needle Plate Locating Plunger Spring #82172 and Releasing Lever #82173

Function and Purpose:

The Locating Plunger is a specialized alignment pin used in the needle plate and pinion assembly of vintage industrial shoe patcher machines. It is designed to lock or release the needle plate in a specific position to facilitate maintenance and directional sewing operations on leather goods and footwear.

Key Functions:

Needle Plate Alignment: Ensures the needle plate is perfectly centered over the pinion and shuttle mechanism, which is critical for accurate 360-degree directional stitching on boots, bags, and leather repairs.

Release Mechanism: Functions as a release pin, allowing the operator to quickly disengage or reposition components during leather repair tasks and maintenance procedures without disassembling the entire needle plate assembly.

Mechanical Stability: Prevents the plate from shifting under the high pressure of industrial leather sewing, maintaining consistent stitch quality and preventing needle strikes or timing issues during heavy-duty operations.

When to Replace:

Replace this plunger if the needle plate becomes loose, shifts during sewing, or if the release mechanism fails to hold the plate securely. A worn plunger can cause alignment issues and inconsistent stitch formation on leather work.

Compatible Singer Models:

Singer 29K Class: 29K71, 29K73

Singer 29U Series: 29U171A, 29U172A, 29U173A

Generic Compatibility: Fits most patcher and cobbler machines that follow the original Singer 29K design

Professional Tip: For complete repair, pair this plunger with the Needle Plate Locating Plunger Spring (Part #82172), which provides the tension required for the plunger to stay properly seated. Regular inspection of this assembly ensures reliable needle plate positioning for professional leather work.