After making the jig with bearings for the jig saw that allows me to make a perfect vertical cut at 90 degrees in wood (preventing the blade from making a crooked cut vertically), I thought a similar jig could also work for vertical 45-degree miter cuts. So in this post I’m going to make a jig for cutting wood with the jigsaw tilted to a 45 degrees angle.
The base and bearings support of this new woodworking jig is basically the same as in the previous jig. But three changes are necessary.
First, after making the plywood base, the one on which I will be able to attach the jigsaw with the help of some screws and wing nuts, I have to cut the slot for the blade at a 45 degrees vertical angle.


I start by tilting the jigsaw 45 degrees to the wrong side. Notice that that is the wrong side to tilt the jigsaw because when using this jig I will tilt the jigsaw to the other side. And with that inclination I cut the slot in the plywood base.

Now I tilt the base of the jigsaw to the opposite side. And in this way, when I attach in the correct position the jigsaw to the plywood base, the blade clamping system will be aligned with the slope of the slot.

Secondly, I have to change the position of the reinforcement that I put on the support where the bearings will go. This time I have to put the reinforcement flush with the front of the bearings support.



And thirdly I have to modify the way in which I put the bearings, as putting them directly in the support with the correct angle becomes very complicated. That’s why I decided to screw the bearings to a small piece of plywood. I will place this piece of plywood (with the bearings) against the support in the correct position and at the correct angle.

With the jigsaw cutting blade installed, I put the plywood piece with the bearings more or less in place, I adjust the position where I have to screw the piece with the bearings to the support, and I also mark where to cut what I have left over from the plywood piece where I screwed the bearings.

Once I have the piece with the bearings ready, I adjust its position with the help of an architect’s square (it is the most accurate square I have in my small woodworking and do-it-yourself workshop). In order to put the square against the blade, as shown in the picture, I had to remove one of the bearings.


I screw the part where the bearings go to the support, and I put the bearing that I had removed back in place.

I make sure that the blade is perfect at a 45 degrees angle in this jig for cutting vertical miters with the jigsaw …


And now I can cut vertical miters in wood at a perfect 45 degree angle.

I think I’ll need a little bit of skill to use this jigsaw jig, but I’m sure it will come in handy for many woodworking projects. And after the first tests I am happy with the result when cutting the wood, so I’m sure it will help me to get some nice miter joints.