DIY jig to cut large wood beams

So many times I needed to cut a large beam! But I could not do that using the circular table saw in a single pass. I tried different ways of performing the combined cuts using the circular saw, so that the two cuts to be perfect, but without any results.

You can also read more about how to make laminated wooden beams by using a homemade clamping system which helps you build them very quickly and without hand pains.

The only solution I have found was to build a DIY beam cutting jig easy to be done. And of course it did not have to cost too much.

The advantages of using this perpendicular beam cutting jig are:

You need to make one single measurement, so that you can avoid the differences that can occur from two-side measurement.
You can do repeated cuts very quickly, so that you earn considerable time on projects involving many cut large wood beams.
In order to build it, you only need the circular saw, a square, a fir wood plank and four screws
You can build it any time you need it in a very short time. It is very cheap and it can be built using scrap woods

The less pleasant part is that you have to build such cutting jig for each wood beam size that you want to cut. Another disadvantage is that it can be damaged in time (this thing depends on the temperature and the humidity). That’s why I prefer to make a new one for each project.

In order to build this cutting jig, I chose a fir wood plank (of about 10 cm wide and 2 cm thick). I cut three pieces with the circular saw, using a square as guideline, to make sure that the cuts are perpendicular. The dimensions of two wood pieces are not important, the only condition is that they have to be longer than the thickness of the fir wood beam. The third piece must be 0.5 mm longer than the thickness of the wood beam you have to cut.

I measured the thickness of the fir wood beam — Measuring the thickness of the fir wood beam

I used a fir wood plank to create the wooden jig for cutting the large beam — The fir wood plank used to build the cutting jig

I used 3 pieces cut from a wide fir wood plank to build the handmade jig for cutting large wood beams — The three pieces cut from a fir wood plank

We fixed the wood pieces with screws, taking care that the two pieces that will be used to guideline the circular saw, to be in the same plane and to be perpendicular on the third piece. The checking was done by putting the wooden jig on a MDF board.

checking the flatness of the cutting jig made to cut large fir wood beams — Checking the flatness of the cutting jig

That was all! I went to test the cutting jig. After the first cut, I saw that there were still some small adjustments that I had to do, but they were easily done due to the fact that the jig was made out of fir wood. At the second check the cut was almost perfect, the only problem being that I made a little mistake so that at the end of the cut it appeared a little circular traces. I did not fixed the wood beam on the table, so a hand was busy to hold the wood beam and I could not keep the circular well with both hands.

I made the first cut using of the circular saw and the handmade jig for cutting large wood beams — First cutting, with the circular

this is the obtained cut of the large fir wood beam using the handmade guide — The final result

the cut end of the large fir wood beam is placed perpendicular on the MDF board — The beam is placed perpendicular on the plane

I checked the perpendicularity of the cut by putting the wood beam on a MDF board and placing the square near two sides of it. For my ongoing project I did not need too much precision, so I decided to sand the circular traces.