Adjust a Table Saw Fence Using a Dial Caliper

Today I found a new use for my dial calipers that I thought I'd share.

I'm in the process of making several drawers for some built in cabinets in my shop. The bottom of the drawers will be 1/4 inch plywood. Of course, 1/4 inch plywood is not really 1/4 inch. It's more like 3/16 inch.

I couldn't use my stacked dado set to cut the grooves in the drawer sides, since there is no way to make it narrower than 1/4 inch. Instead I made two passes on my table saw using my combination blade.

The first pass was easy. I simply set the rip fence to the distance between the bottom of the drawer and the bottom of the dado, set the height of the blade to 1/4 inch (half the thickness of my drawer slides) and made a pass to cut a 1/8 inch groove.

To make the next pass, I could have slid the fence over, made a test cut, adjust the fence, make another test cut and so on until the width of the dado was correct. Instead, I used my dial calipers to move the fence once and end up with a dado the perfect width.

I started by measuring the thickness of the plywood with the dial calipers. In this case, it measured 0.187 inches thick, give or take a thousandth or two. Then I placed the end of the dial calipers against my table saw fence and slid the movable head out until the inside of the jaw was against the miter slot. After locking down the head, I zeroed out the dial. I then opened the dial calipers an additional amount equal to the difference between the plywood thickness and the width of my table saw blade -- 0.062 inches in this case.

Now I could move the table saw fence. I moved the fence to the right, held the jaw of the dial calipers against the miter slot, and then moved the fence until it just touched the end of the dial calipers. A test cut confirms the fence setting and I was ready for the second pass to make my dado.

So the next time you need to adjust one of your tools, think about using your dial calipers, it just may help you adjust things correctly the first time, without a lot of trial and error

Cut Plywood Down To Size By Yourself

Working with plywood brings a set of challenges different than working with solid wood. One such challenge is simply the sheer size of a plywood sheet. Working with a 4x8 sheet of plywood by yourself can be diffult. In this post, I'll cover some of the ways of to break down plywood into more manageable pieces when working solo.

Leave it to the Lumberyard

One of the easiest ways to deal with large plywood sheets is to not deal with large sheets of plywood. Many lumberyards and home centers will, for a small fee, make a few rough cuts for you. The first couple of cuts may even be free. This way you take pieces that are much more manageable to your workshop.

If you have the lumberyard make some large cuts, have a cutting diagram worked out ahead of time. Also, have the cuts on the panel saw made about 1/2 inch to 1 inch oversize. Don't expect the panel saw operator to be able to cut your piece to within 1/64 inch of your final dimension. Cutting pieces oversize also allows you to deal with any tearout and irregularities in the cut at your shop. The blade on the panel saw at the lumberyard may not be the sharpest in the world and will likely leave a rough cut at best.

Circular Saw

If you have a portable circular saw, you can break down plywood into rough pieces using a straight-edge. Some circular saw systems, such as the Festool, are accurate enough that the cuts don't need to be cleaned up on the table saw.

Whether you use a commercial system or a home made straight-edge, the idea is the same: Lay the panel flat on some sawhorses or on a piece of foam on the floor, line up the straight-edge with a couple of marks parallel to the opposite edge, and guide the saw along the straight-edge to make the cut.

After cutting pieces to rough size, you may need to clean up the edge or break it down further on the table saw.

Table Saw

I wouldn't suggest cross cutting a sheet of plywood on the table saw, but it is possible to rip plywood on the table saw by yourself. To do so, it's important that you have a way to support the sheet on both the infeed and out-feed side of the blade. In my shop, I have a large table behind the table saw and I can use my workbench and some roller stands on the infeed side. The main idea is to support the sheet so that you don't have to hold it up in addition to maneuvering it through the saw.

When feeding a sheet of plywood through the table saw, keep an eye on the table saw fence. You want to make sure that you're keeping that edge against the fence. It's very easy for the sheet to rotate away from the fence and ruin your cut.

These are just a few ways to break down a sheet of plywood. What tips and tricks do you have for breaking down plywood into manageable sizes?