In our first post, I've shown you a cheap and easy way to mill timbers.
This method never gives perfectly square logs and drying of beams can sometimes result in twisting or bending of the timbers. As you can see in my picture below.
Squaring up timbers on a planer
Squaring up timbers isn't easy. What a planer does is plane 1 side flat. Imagine a banana dragging over a table when you drag it only the beginning & end of the banana touch the table. The planer cuts 1 or 2 mm of the beginning and the end because the rest of the banana didn't touch the table. If you repeat this process you have a smaller but straight banana in the end.
So we now have 1 flat planed side on our banana our second goal is to make the other 3 sides of the "beam" also square.
The second problem with a planer is that it doesn't make it automatically square with the next edge.
The drawing below explains it better. If you plane the beam in model A you only plane the pointy edge away and thus making it more square. In drawing B you end up with 1 pretty planed side that isn't square.
Video how to use a fence on a planer:
Posted with STEMGeeks