The Smell of Molten Projects in the Morning

Ed Nisley's Blog: Shop notes, electronics, firmware, machinery, 3D printing, laser cuttery, and curiosities. Contents: 100% human thinking, 0% AI slop.

The New Hotness

  • Plastic Spring Clamp Jaw Rod Replacement

    A recent quilt photo shoot degenerated into me chasing several bright orange clamp jaws across the deck as they popped off their clamps hanging from the photo backdrop scaffold. Most clamps have jaws snapping onto actual rods, but these clamps have molded-in-place “rods” much smaller than the 2 mm expected by the jaws and much more irregular than seems reasonable.

    Trace and scan the nose of a clamp:

    Large spring clamp nose outline
    Large spring clamp nose outline

    Curiously, the molded rod is not centered in the nose:

    Large spring clamp nose - pin locatIon
    Large spring clamp nose – pin locatIon

    Use LightBurn to coerce a scan of the first sketch into a suitable path, laser-cut some MDF, and glue up a drill fixture:

    Spring clamp jaw pins - fixture gluing
    Spring clamp jaw pins – fixture gluing

    Align the drill to the center of the off-center hole marked on the bottom layer:

    Spring clamp jaw pins - drill alignment
    Spring clamp jaw pins – drill alignment

    The drilling setup looks casual, but hand-holding the clamps against the rear wall and into the form-fitting nose recess sufficed:

    Spring clamp jaw pins - fixture overview
    Spring clamp jaw pins – fixture overview

    I snipped the plastic “rods” out before drilling the holes, then rammed 2 mm steel rods in place:

    Spring clamp jaw pins - steel
    Spring clamp jaw pins – steel

    They’re really 5/64 inch = 1.98 mm rods from the oil-hardening drill rod stash, but entirely sufficient for the purpose.

    With one clamp in hand, though, there was obviously no reason for the rods to be off-center. So I centered the drill in the nose, punctured the rest of the clamps, and pressed 2 mm carbon fiber rods in place:

    Spring clamp jaw pins - steel vs carbon fiber
    Spring clamp jaw pins – steel vs carbon fiber

    The rods were cut to 20 mm by rolling them across a pad with firm pressure from a utility knife. That was mostly to get some experience cutting carbon fiber, which is obviously overqualified for the job.

    Snap the orange jaws in place and I shall never suffer the embarrassment of chasing them again …