Use the Sighting Square (Not a Joke)

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Brendan’s video demonstrating his “chairmaker’s sighting square” was a bit of a joke. But the square itself is something we use all the time in the shop when drilling tricky angles.

You don’t have to build one of these squares – an aluminum framing square works just as well – but the wooden ones are nice. Here’s how the square works.

First the driller places the bit on the crest rail and lines up the drill with the hole locations on the crest and the seat (totally by eye). The driller can easily see if he (or she) is tilted too far left or right. But he can’t see if he’s tilted too far forward or back. This is where the sighting square comes in handy.

Place the sighting square on the crest with one of its legs in line with the drill and the bit (shown above). The “boring buddy” then sits at the other end of the square – basically, 90° to the axis of drilling.

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Then the boring buddy holds up the sighting square, lining up the point of the drill bit with the hole location in the seat and one leg of the square. She can easily see if the driller needs to lean forward or backward to achieve the correct angle.

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Works every time (as long as the boring buddy isn’t blind).

— Christopher Schwarz

About Lost Art Press

Publisher of woodworking books and videos specializing in hand tool techniques.
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10 Responses to Use the Sighting Square (Not a Joke)

  1. nrhiller says:

    Megan is anything but boring.

  2. Dan says:

    I am having trouble following the procedure, which is unusual because I usually find your instructions clear and idiot-proof (which is how I need them). Specifically, I’m missing something in the transition from second photo to the last photo. In the second photo, Megan is holding the very end of the long leg of the stick so that the intersection is at the point of the drill, and the short end is perpendicular to the axis of drilling. Then in the final photo the short end of the stick is no longer on the crest, and in fact is not visible in the photo. Megan is holding the long leg, and I gather from the description that what she’s doing is using the long end to imagine the line that would run from the appropriate spot on the crest, where the bit is touching the wood, to the hole bored into the seat. Once she’s established that line, she can tell whether the drill is parallel to it; if not, the drill needs to be adjusted forward or back.

    I can see the importance of holding the imaginary line showed in the third photo. I guess I don’t understand how the preliminaries helped her get there. What would go wrong if the boring buddy simply sat down perpendicular to the axis of drilling, and then held up a dowel in a line that would run from the drill bit to the hole in the leg? The only answer I can think of is that the first step helps her make sure that she is truly perpendicular to the axis of drilling. And I can see why setting up this way would be more precise than just eyeballing it. But I guess I don’t see why that precision doesn’t get lost when she then pulls the short end of the square off the crest, adjusts her grip , and flips the square around so that she can hold it on the imaginary line. Is the idea that the first step is just telling her precisely where she needs to sit? Maybe what I’m really missing is the transition from the first photo to the second–Is the difference between the first and second photo that in the first she’s standing, and once she’s gotten it lined up she pulls up the stool and sits down in that precise spot, which means she’s in a good enough position that she can then reliably eyeball the imaginary line?

  3. jenohdit says:

    It would be a lot easier to use a straightedge from the rail to the seat. If for example the crest rail is 2″ wide and the hole is centered, then a straightedge from the front edge of the rail to a point 1″ towards the front from the mark on the seat establishes the line. Easy to do for one person. Easier with someone eyeing the side view.

  4. Joe says:

    And if your boring buddy is actually blind, it still works some of the time.

  5. Adam says:

    Invention is the mother of necessity, I see

  6. Paul Cleary says:

    A close-up picture please of the dust extraction device for the bandsaw that seems to be sitting on the top of the dust extractor in the background?

    • tsstahl says:

      I’m always wrong when I make these guesses, but here goes anyway. Looks to me like simple accessory storage on a Fein or Ridgid vacuum.

  7. Stephen Newsome says:

    Hi Christopher
    What is the drill extension in picture 1 and 2?

    Stephen

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