The table saw is easily my favorite tool. For me, it is amazingly versatile in what it can do and when you start adding jigs to it, the table saw can do some amazing things. I am currently on my fourth, and possibly my last table saw. Since none of my saw, including this one, hand the same fences, many of my jigs I have had to re-make, including this bevel cutting jig. Hopefully this version will also be my last because I am going to make it with a small amount of adjustability in mind. Something I neglected on my last versions. To be honest, the last versions of the Bevel Cutting Jig that I made, were all rushed together quickly to satisfy an immediate need. This one I am making without that immediate need and with the knowledge that I will be using it in the future.
The biggest problems I had in the past with this jig was - storage. All my jigs needed to be stored in an unheated outdoor shed. This means the wood moved a lot. In the winter it is cold and damp and the wood expands to around 14% moisture content. In the summer it's often hot and dry the wood shrinks down to 8%. Now all this is not huge, but when you are working with close tolerances, like on a metal table saw fence. A jig I make in the summer, will certainly not slide back and forth on the table saw fence in the winter, in fact, some won't even fit over the fence they have expanded so much.
This time I am going to select my wood carefully and make the part the slides over the table saw fence, slightly adjustable without having to take it apart and re-make it ...
So ... for the upright, I chose MDF (medium density fibreboard). It's flat and straight and it stays that way, and even if I have to store it outside, I can seal it water based varnish to prevent it from absorbing moisture. The cross member part will be Red Oak this time. Red Oak does absorb moisture but because it is so dense it does this slowly and if I seal the ends, this make the wood only absorb moisture through the sides which it will do very slowly and evenly so having a jig that is sticking on the ends but loose in the middle will be less of a concern. The outside piece will also be a hardwood, could be oak, maple of whatever I have that fits and is a bit of an orphan in my wood pile.
The size of the upright doesn't matter, except it needs to be manageable and sufficient to you as the woodworker to manage as you move it through the saw blade. The cross member Red Oak, typically wants to be as wide as the upright and needs to be trimmed to width first and should be just slightly narrower than you table saw fence .. by about the thickness of 3 sheets of paper. the back upright also needs to be about as long as the cross member piece but it needs to be cut slightly higher than what the cross member piece is as it sits on the fence. The reason for this is to give yourself some room for fasteners, including washers so they have a good backing when it comes time to tighten the whole jig together.
The first components that need to be attached are the upright and the cross-member piece. I used a thin veneer to lift my upright off the table saw deck so that when I move the jig back and forth the bottom of it will not hang up on the table saws mitre slots. I used a very wide head screws to attach mine but made sure they were countersunk deep enough. and this time, I constructed the jig on the table saw for a much tighter and accurate fit.
Next to be attached is the back upright, but this time in stead of just screwing it to the cross-member piece I decided to use Hangerbolts ... wood screws thread on one end, machine screw thread on the other. To make sure these fit, I clamped the outside piece to the cross-member and drilled 3 pilot holes through the back upright and into the cross-member. Later I used a larger bit to enlarge the holes for the hangerbolts to be driven in and to make sure the back upright fit smoothly on once all the hangerbolts were attached.
The final bit of trim, and an important one, is to attach a thin strip of wood to the upright to use as a backer when running wood through the saw blade. Make sure that you use wood that is suitable fo this and that your lowest screws (if you are attaching with screws) is ABOVE the height of the saw blade.
Whenever I have used one of these jigs, either mine or someone elses, I have always found they are not perfectly rigid at the top, there will always be a bit of sway but that should not affect your cuts because the cuts are done low down on the jig and the wood is wedged betweent the saw blade and the jig so a tiny bit of sway before you start cutting should transform into a firm, tight cut when you are done.
Copyright Colin Knecht