After making the guide with bearings for the jigsaw blade that allows me to make a perfect vertical cut at 90 degrees in wood (preventing the blade from twisting vertically), I thought a similar guide could also work for 45-degree vertical miter cuts. So, in this post, I am going to make a jig for cutting wood with the jigsaw tilted to a 45-degree miter.
The base and support for the bearings of this new jig are basically the same as the previous one. But three changes are necessary.
First, after making the plywood base, the one where I can attach the jigsaw with the help of screws and wing nuts, I have to cut the slot for the blade at a 45-degree vertical angle. I use the same long jigsaw blade that I used with the 90º jig.
I start by tilting the jigsaw base 45 degrees to the opposite side of where I will use it in this jig. And with that tilt, I cut the slot in the plywood base.
Now I tilt the jigsaw base to the opposite side, and in this way, when attaching the saw to the plywood base, I have the blade clamping system aligned with the angle of the slot.
Second, I have to change the rib of the support where the bearings will go. This rib must be flush with the front of the support this time.
Third, I have to modify the way I place the bearings, as placing them directly on the support with the necessary angle is very complicated. That is why I decided to screw the bearings to a strip of plywood. This plywood strip will be placed against the support in the correct position and at the correct angle.
With the jigsaw blade installed, I place the strip with bearings more or less in place, adjust the position where I need to screw the support to the plywood base, and also mark where to cut off the excess from the strip where I placed 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 precise square I have in my small woodworking and DIY workshop). To be able to support the square against the blade, as we see in the photo, I had to remove one of the bearings.
I screw the piece with the bearings to the support and put back the bearing I had removed.
I make sure the blade is perfect at 45 degrees in this jig for vertical miter cutting with the jigsaw…
And I can now cut wood at a perfect vertical miter angle of 45 degrees.
I think I will need a bit of skill to use this jigsaw jig, but it will definitely be useful for many woodworking projects. And after the first tests, I am happy with the result when cutting wood, so I am sure it will help me achieve nice miter joints.
