Wooden straight edge

[poolhound]

In anticipation of the need to setup the wings and extensions of my new table saw I decided it was time to have a real straight edge in the shop. I didnt have the desire for anything too fancy and in the end went for a set by Fulton from Peachtree. They arrived today with perfect timing as the saw got assembled yesterday. I just checked out the main table of the saw and it was pretty dang good when measuring across the diagonals with the biggest gap I could measure being no more than 4 or 5 thous. right at the edge of one corner might be a bit low at .008/9 but that's still within the manufacturing tolerance which Sawstop quotes as .010. I am pretty happy.

Now to the topic of this post. Quite a few years ago in need of a straight edge and not having one, I made a pair of wooden ones, yes straight edges made from wood! I had found more than one article explaining how to do this and how the choice of wood and the design mitigates the issue of wood moving. I was skeptical but it all worked and they have served me well for years. Having just received the machined metal straight edges I compared the measurements I took with them with my wooden versions. FYI these have never been trued or changed since I made them which was at least 5 years ago and here in AZ they will have experienced temps from freezing to 120F and humidity from less than 10% to more than 70%. In this non scientific test I would say they produced results pretty close to the new metal edges +/- .001" !!!

At the end of the day we are woodworkers not machinists and work with an imperfect and ever changing medium. If we can get close to 1/64" (~0.016") worth of accuracy that's pretty amazing and even then it can shrink/grow by a 1/4 or even 1/2 each year. I was really amazed at how a straight edge made from wood held its own against a metal one.

Jon

[LCHIEN]

If you don't have some reliable straight edges like Jon,
you can get some 4-foot or 6-foot levels that are going to be pretty straight. for a reasonable amount of money.

[Jim Frye]

In addition to the long levels that will be useful forever, I have a six foot long aluminum bar stock that I bought decades ago at a big box store for use as a long straightedge. It was inexpensive, light weight, and is easy to tape to things for hands free use.

[Jim Frye]

The 6' aluminum bar stock I bought for a straightedge also lent itself to an additional tool. It also serves as a trammel bar for laying out large radius curves. I used some red oak scraps and some 1/4x20 bolts to make the trammel bodies. Nothing fancy, nor terribly ingenious, but they work.