How I Built a Sawmill in the Backyard

Woodworking is a recent hobby of mine. I’m lucky to have a pretty capable garage full of tools I bought in my single days. Pro-tip: get those toys before you’re married! Since starting a family (second kid on the way), its become harder to afford woodworking tools! Machines and consumables aside, the raw material is out of my budget.

There is a lot of wood around my house in the form of freshly fallen limbs and trees. I’ve looked at it and thought, “If only I could free the boards within.” Commercial sawmills are big and expensive, but as I started researching them a voice inside my head said, “Hey, I can make one of those!”

When looking at a bandsaw mill, there are really only three parts: the bandsaw, a gantry that holds it horizontally, and rails that the whole thing can slide on. There are some tricky parts, but I ignored those at first and just jumped into building.

There’s something to be said for having theories and plans, but too often I get bogged down in design. No CAD designs or paper sketches went into building this. The only calculations I made were for figuring out pulley sizes to get the right blade speed (2800 fpm) and determine how far apart the wheels should be for a certain blade length. I designed on the fly using my own experience and intuition as a guide – something I refer to as “eyeball engineering.”

This worked well for some things. I came up with a clever design for tensioning the blade based off milling machine ways. I figured out a way to make the blade guides using just simple bearings and some scrap pieces. I felt that most DIY sawmills used way too much metal and were too heavy, so I built mine with the least amount of steel that I could, and ended up with a very capable lightweight machine.

However, some of my intuition was way off. I had assumed a 1 HP AC motor was more than enough for ripping 20″ logs. Well, the first time I used the saw this motor overheated and almost caught fire! I have a much better understanding of horsepower now.

Also I didn’t understand the intricacies of bandsaw blades well enough. I’m embarrassed to admit that I didn’t even order a blade until the saw was almost done. I had done no research on blades up until that point. The blade I did buy wandered badly in the cut, or rubbed against the wood and fell off several times. Because the first blade I bought was too narrow, there was no hope for the blade guides to do their job.

The first thing I did in my second revision was to replace the motor with a “small” 6.5 horsepower gas engine. In terms of cost and weight per horsepower, gas wins hands down over electricity.

Next I replaced my blade. In hindsight I know how crazy it was to not begin my design with the part that does the actual cutting. It turns out there are only a few blades on the market that will work with a small saw like this, so I ordered one of each. This started to get expensive, but I chalked it up to research. I was lucky to find one that works great. It was also the thickest, cheapest, and the one I thought for sure wouldn’t work.

The result is a little sawmill that just tears through trees! I was very surprised at how well it works. I just wanted to try it and ended up milling an 18″ diameter, 6′ long log of spalted maple into over a dozen 6″x1″ boards. The cedar log that I cut up next revealed an awesome purple heartwood. I started milling wood and just couldn’t stop. I eventually came to my sense and acknowledged that this saw has almost zero safety features. My very next step before cutting another board is going to be installing guards around the blade and drive belt. I will also add a push handle.

Then there are the rails. The screwed together 2×8 lumber worked surprisingly well, but the whole thing will probably only last one season. I roll the logs and then screw them to the wood. This has worked pretty well, but it’s slow and the rails are getting beat up. I will eventually replace it with a welded metal frame that has built-in clamps for holding the logs. In fact, if I were to build another mill, I would literally start from the ground up and focus first on log handling and making a solid foundation for the rest of the saw.

Take a look at my videos for more detail on the build and to see it in action. I will post an updated video soon, so please subscribe to my channel and stay tuned!