How wide is it?
If you don’t have a folding rule with a metal extension bar, you can still accurately measure inside a drawer or similar workpiece by using a retractable tape measure and a combination square. Place the square against one corner. Starting at the opposite corner, measure the remaining distance with the tape measure. Add the two measurements for the total width.
Too round for rules:
Finding the exact diameter of a round object isn’t that tricky. Place the object against a straightedge rule tnd between two blocks or other items with true straight edges. Then just read the diameter on the rule (the distance between the blocks). You can create variations of this gauge with a mix of try squares, framing squares and combination squares.
Improvise a depth gauge for stopped holes or recesses with a bolt and two nuts. With the nuts on the bolt, place the bolt in the hole. Twist the nuts down to the surface of the work. To hold the measure in place, tighten the top nut to the bottom one.
A car mechanic’s gauge for measuring the depth of tyre treads is also a handy gadget for the woodworker. Use the gauge (which measures in increments down to 0.5 mm) to check the depth of stopped holes and shallow recesses.
Use a combination square to determine, the depth of a recess. Making sure the blade is free to slide, rest the square on a flat edge of the work. Adjust the blade to the depth of the recess, then lock the blade in place using the thumbscrew. Besides measuring the recess, you can use the square to transfer the depth dimension to other workpieces. v
If you’re not sure that an edge is straight, place it against a known straightedge and hold the two pieces up to a light. If the light shines through, the edge isn’t straight. To straighten it, shave off the high spots with a file, sander or plane.
Get it square:
When making a rectangular object, such as a drawer, check that it is actually square. Here’s how. First measure across the workpiece diagonally from corner to corner. Then measure along the opposite diagonal If the two measurements match, the workpiece is square.
To make sure that a right angle is true, use the 3:4:5 method of triangulation. For example, to check a corner for squareness, measure three units along one wall and four units along the other. If the distance between the two end points is five units, the corner is square. To create a right angle, tack two strings where you want the right angle to be. Measure two legs of a triangle; one 12″ (300 mm) and the other 16″ (400 mm). Position the two legs so that the distance between their end points is 20″ (500 mm). You can also figure in meters, or in multiples of 3, 4, and 5 if you use the same multiple for all three.
Chalk it up
Back to school:
To identify parts when assembling a project, use white or yellow blackboard chalk. It’s easy to sand off, and chalk doesn’t leave a hard-to-remove impression the way a pen or pencil can.
When marking budding material with a chalk line, first remove excess chalk from the line by snapping it on the ground or floor or against studs or joists. Then you’ll be ready to stretch the line over the material and snip it as usual. The result will be a crisp line.
You can find the centreline of an odd-size board without having to divide awkward numbers. Place a rule or measuring tape diagonally across the board with an even numbered inch or 1/2″ mark on each of the board’s two edges. Subtract one figure from the other and halve it to locate the centre of the board.
A windy day can make it difficult to Use a plumb bob. To keep the bob from bobbing around, sink the weighted end in a bucket of water. (The bob shouldn’t touch the side or the bottom of the bucket.) Since you can’t align the work directly against the plumb bob string, measure the distance between the work and the string at the top and bottom. If they are aligned, the measurements will be the same.
To mark equal segments, angle a ruler across the work. Place the beginning of the ruler on one edge of the work, and adjust the angle so that a 1/2″ mark divisible by the number of segments needed lies at the other end of the work. For example, to divide a 6″ wide board into 7 segments: let the ruler measure 7″; then mark every inch.
Walk this way:
Another way to mark equal segments is with dividers or a compass. Set the points at the desired distance; then walk the dividers along a straightedge by swinging one point in front of the other.
In the round
To find the centre of a circle, clamp a combination square to a framing or try square. The combination square should be set against the framing square so that its rule intersects the inside corner of the framing square at 45 degrees. Slide the contraption over the work until both sides of
the framing square rest against it. Using the rule of the combination square as a guide, draw a pencil line on the work; rotate the work and draw a second line. The intersection of the lines marks the centre. You can also make a plywood jig. Cut out a right angle in the plywood; then attach a straightedge to it with screws, creating a 45 degree angle. Use the jig in the same way as the one above.
To mark equal distances around a cylinder, measure the circumference with a strip of paper; then lay the paper flat and mark off equal segments with a compass. Wrap the paper around the cylinder, tape down the end, and transfer the marks.