Video: Re-Use Soft Jaws with Expanding Pins

When tool-and-die and contract machine shop Baklund R&D developed a workholding device to solve a challenge with one of its own jobs, the company realized it potentially had a solution that could benefit many other shops as well. The “Expandable Collet Pin” is now a standard product marketed by Baklund Workholding, a sister company to the shop.

The video shows how the Expandable Collet Pin facilitates the reuse of soft jaws on machining-center vises. The pin simply requires 1/2-inch holes to be drilled in vise faces (as Baklund R&D has now done throughout its shop). Whereas aluminum soft jaws are often considered disposable because of the difficulty with relocating them for reuse, the pin provides for secure and repeatable clamping. To secure the jaw, it expands within the hole as it is tightened—holding to 480 pounds of pull force and locating to ±0.0003 inch, the company says.

This solution evolved from a clamping challenge related to a large forging that lacked straight sides. After some initial ideas failed to hold the part well, Baklund R&D at last hit upon creating a 4-inch-diameter expanding collet pin to grip the component within a large bore that was a feature of the part. Watching how well and how consistently this collet held the part, shop owner Jon Baklund realized he could apply the same solution to workholding using collet pins scaled down to a smaller size.

In fact, because of the repeatable locating with the pins, jaws can be turned, flipped and accurately re-located. That means four different edges can be used to clamp four different parts with a single set of jaws. The video emphasizes this advantage.