Logan Cabinet Shoppe

With the built-in finally finished, I had some time to work on a few shop projects I've been wanting to do for awhile. The first was the saw vise that I completed a couple of weeks ago. This weekend's project has been something I have wanted to make for awhile now but continued to put off because there were other ways to accomplish the task this tool does. After the recent sale of my old long steel rulers, I decided the time had come to finally make these.

If you are not familiar with them, they are called pinch sticks, pinch rods, and I'm sure several other names as well. Their sole purpose is to aid in squaring up cases. To use them, you place the pair of sticks inside the assembled box, extend the sticks until the points on the ends nest into the inside corners of the case and lock them down with the captured wedge or thumbscrew. If one diagonal is longer than the other, it will immediately be obvious using this tool. You then simply adjust the case until both diagonals are the same at which point your case is square. Of course you could do this with a long ruler, but with the pinch sticks there is no measuring involved so there is very little room for error. I made several sets in different sizes that will let me use them to square diagonals anywhere from about 8" up to about 60".

Here's a closer picture of the middle set to give you a better view of how they work. The middle block is simply a square block with a through mortise bored and chopped through its center. The mortise is sized to the width of the sticks and their combined thickness. I cut all four blocks from a single piece of wood. I bored and chopped all of the mortises prior to cutting the individual blocks apart to provide an area for holding the stock while cutting the joinery. At the top of the mortise for the sticks on the two smaller pair, an angled wedge mortise is cut and chiseled for the captive wedge that locks the sticks at their setting. I made the blocks from ash and the sticks and wedges from oak. The sticks on the two smaller pair are each about 1/4" thick by about 5/8" wide. The wedges are 1/4" thick.

The sticks on the larger pair are made thicker, about 5/16" thick, so they flex less along their long, 30" length. Since the sticks on the longer pair are thicker, the mortise had to be bigger. Because I cut the blocks from the same small piece of wood as the blocks for the smaller pairs, there was less supporting wood left for a captive wedge mortise to be cut. I was afraid that there would be insufficient material left to support the wedging force without blowing out the end grain on this larger pair so I used brass thumb screws cross grain in place of the captive wedge. The difference is that the blocks end up oriented differently when the sticks are inserted. The wedging forces of the captive wedge need to be in line with the grain for maximum strength. On the other hand, end grain does not tap well so the holes for the thumbscrews needed to be bored and tapped cross grain for maximum strength. I bored and tapped a hole centered on each mortise for a #10-32 brass thumbscrew. To keep the screws from marring the faces of the sticks, short sections of 1/8" oak dowel were put in the holes before putting the screws in. The dowels will then provide the clamping pressure on the sticks, not the screws. This picture was taken before the two blocks for the large pair were cut apart.

This was a long overdue project and I see these tools getting a lot of use in the future.

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