Shop Made Clamp
by Edwin C. Hackleman

In many respects,   I like my clamp design better than a clamp screw or a C-clamp.   I admit that my clamp won't obtain the clamping pressure of a C-clamp, but the throat is deeper and it won't leave a "frog eye" on the work piece.

Also, you can adjust it far more rapidly than either a clamp screw or a C-clamp.   You can make the clamp about as long as you want, although a maximum realistic jaw opening is probably about 18".   That sure beats a C-clamp or a clamp screw.   Also, like the clamp screw, you can clamp round dowel stock, which the C-clamp cannot do.

The plans I show yield an average-size clamp with jaws that can reach in about   5-1/2"   and open about   8"   wide.   I made this with from one   24"   length of threaded rod, a hex nut, a washer, and a wing nut--all   3/8"   stock.

  •   The jaws are made from one piece of   5/4 hardwood   that I cut from a   9" x 3-1/2"   blank.   I shaped the clamp knob from a cutoff scrap.

  •   Before cutting the blank in half, Drill a pair of   3/8" dia.   holes for the threaded rod a little over halfway through its width.

  •   Drill four   1/2"   dia holes through its thickness to mark the rounded corner positions of the interior cut outs.

  •   Cut the blank in half, with the table saw,
    dead center along its length.

  •   Drill   5/16" blind holes   for the threaded rods in the bottom jaw, stopping just short of the bottom surface.

  •   Route the V-groove on both jaws to allow clamping round stock and cut out the jaw opening using the band saw.

  •   Note: That extra clearance has to be provided for the wing nut on one end.

  •   Thread the   5/16" blind holes   with a   3/8" NC tap.

  •   Cut and rounded the outside corners with the band saw and and used a   1/4"   roundover bit to eliminate all sharp edges on the inside and outside edges.
    However, Do not round over the two clamping surfaces.

  •   Cut the two threaded rods to length with the inside rod an inch longer and chamfered all four ends.

  •   Temporarily use a pair of jam nuts to set them tight into their blind holes in the lower jaw.

  •   The rod for the clamp knob needs a washer on the bottom jaw and a hex nut to hold it tight, but the outer rod needs only a wing nut facing upward.

  •   Make the clamp's spinner knob using   7/8"   thick scrap stock by simply cutting a round knob and threading a   5/16"   hole in the center using a   3/8" NC tap.

  •   Spin sand the spinner on the drill press, removing the sharp edges.

  •   Drop the top jaw into place and thread the spinner knob on, adding a little wax or lithium grease to smooth out the spinning action.

  •   Wax up the inside of the holes in the top jaw.

  •   Finally, give the jaws and the knob a couple of coats of 20% thinned varnish to seal the hardwood.

  • So, you are now ready to use the clamp.

    Here's how it works.

    Open the jaws wide enough and squeeze them by hand for a temporary snug fit.   Now spin the wing nut snug against the top jaw.   Use the spinner knob to clamp everything tight.
    Note: The wing nut stops the backs of both jaws cold while the clamp knob does the rest to apply the pressure.

    I suggest that you make one to see if you like it.   Then make a bunch more of various sizes if you do.   I did.


    This site is maintained by:
    Good-Lyddon Data Systems

    Copyright © 2004-2012 Joe Lyddon,