Announcement

Announcement Module
Collapse
No announcement yet.

Doweling jig mod

Page Title Module
Move Remove Collapse
X
Conversation Detail Module
Collapse
  • Filter
  • Time
  • Show
Clear All
new posts

  • Doweling jig mod

    I was going to buy the Joint Genie doweling jig. The price isn't exactly low so I waited and waited and... well I need a non-self centering jig NOW! So I tinkered with a version of the one sold by most woodworking stores.

    Some benefits of the self centering jig are:

    1. it is self centering (see drawbacks, below)
    2. it is less expensive
    3. it has built in clamping useful under some circumstances.
    4. bushings are replaceable (in the model linked to above), no need to buy a different jig.
    5. No need to buy a different jig ti change the bushing size. The same jig accepts various sizes at a cost lower than the entire jig.
    Drawbacks:
    1. unlike Joint Genie, it would be hard to use he jig for applications such as shelf support using dowels. This functionality can be somewhat emulated, albeit not fully.
    2. it is self centering which is not so good when joining pieces of different thicknesses
    I haven't come up with any ideas how to eliminate drawback #1 but the other one is not much of a problem.

    My experiments with the jig were pretty simple. Simplistic in fact. It turns out I can do without Join Genie, and yet I can have most of its functionality.

    All it takes is the removal of one of the jaws of the jig and voila, we have something that works just like Joint Genie.

    Some observations I made:
    1. If one jaw is removed then the offset can be adjusted at will within the parameters of the jig).Under this scenario a clamp had to be used (as shown in a photo)
    2. If the jaw is not removed then the offset of the steel bar can be adjusted by turning the the nut on the threaded bolt.
    3. If the offset is thus adjusted then it will be exactly the same for mated pieces if they are of the same thickness.
    4. If the offset is thus adjusted then for pieces of different thicknesses the offsets will be as follows:
      • on the thinner piece "A" the steel bar will be offset as set by the position of the bolt
      • on the thicker piece "B" the offset will be one half of the difference if thicknesses between piece A and piece B.
    The rest is explained with the equivalents of 1000 words. The measurements shown are not 100% precise as it is hard to hold a camera and the micrometer with a steady hand all at the same time, but they should give a pretty good idea as to how this works.
    Attached Files
    In order to understand recursion, one must first understand recursion.

  • #2
    Re: Doweling jig mod

    Nice, have you considered padding on one side between the jaw and work piece to create the desired offset?

    For instance, if I have a 1" thick piece and want to offset the hole 1/4" from center then I can add a 1/2" thick pad to one side. The jig sees this as a 1-1/2" thick piece and centers accordingly at 3/4" in from each face.

    But with our example 1" piece and a 1/2" pad the hole will be 3/4" in from the outside face of the workpiece, rendering it 1/4" from the opposing face. No adjustment or dismemberment of the jig is required.
    ---------------
    Light is faster than sound. That's why some people seem really bright until you hear them speak.
    ---------------
    “If I had my life to live over again, I'd be a plumber.” - Albert Einstein
    ---------
    "Its a table saw.... Do you know where your fingers are?"
    ---------
    sigpic http://www.helmetstohardhats.com/

    Comment


    • #3
      Re: Doweling jig mod

      I gave the idea a thought or two but I did not experiment yet. I thought that if I need and offset then padding on the side of interest could be done by simply using a shim as thick as the desired offset. The clamping action simply wont allow the centers to go more than by thickness of jig + the shim.

      I gotta tinker some more.
      In order to understand recursion, one must first understand recursion.

      Comment

      Working...
      X