The zigzag seed cleaner

Ok, lets face it: you don’t need anything fancy to clean seed: humans built modern civilization on seeds (wheat, rye, barley, rice), and they cleaned those seeds with the wind and maybe some baskets. There is a great scene in “Tales of the green valley” (a BBC series available for free on YouTube) that actually shows what this looked like in Renaissance Europe. This method still works. So why are we building a fancy gizmo to do the same thing?

Well, I was asked to build this for the Ujamaa Seed cooperative (an amazing organization, with a very cool seed collection well worth checking out). They have found it useful for a few reasons: they are currently a non-profit run by volunteers, who come and clean seed when they can - often after dark, or on rainy days, or on excessively windy days. Not the best for standing outside with a basket - or even laying out a tarp with a bucket and fan, which is of course the high-tech traditional method. The zig-zag seed cleaner contains the mess to the point that it can be done indoors, in just a few square feet. This is, I have to admit, a pretty major plus.

When asked to build this, I found a couple of versions online, with plans. I used a combination of two sets, here and here. The first link, to RealSeeds, has much better and easier to follow plans, but the second had modifications that made the whole thing easier and quicker to clean. which was important to me.

In case the link ever stops working, here is the diagram with measurements:

Pro tip: If you use these plans, and don’t already have a tape measure with centimeter marks - go out and buy one. My sister in law came over, and we spend an immensely frustrating hour firs trying to convert everything, then cutting it and trying to make it fit. Which it didn’t. Fortunately I had bot an extra length of wood. A quick run to the hardwear store and a cute little keyring tape measure (the only one with centimeters) later, and we were kicking ourselves for wasting so much time. We were able to make the measurements, draw out the lines right on the plywood backing board,and put it together relatively easily.

One of the surprisingly tricky bits was cutting the triangles. At first I tried to use my chopsaw to cut the board ends at an angle. That did NOT work, as the endgrain pieces split and went flying as the saw cut. In the end, I had to run a 2x4 through the table saw with the blade at an angle, then cut them to lenght with the chopsaw. Other than that - it is true that some of the angles were not perfect, but a whole lot of wood glue took care of those little cracks.

The half built cleaner, after applying all the wood glue and smoothing things out as much as possible.

The biggest modification in the second link above, and one that I heartily reccomend, is the plexiglass door on hinges. This allows you to open the whole thing, vacuum it out, and even wipe it down with alcohol in just a few minutes between lots of seed. the use of plexiglass did make it harder to make the rotating lever to seal off the holes to adjust the suction: I could have done the on the back of the cleaner, but I ended up drilling the holes in the front and then using a piece of packing tape to adjust the suction. Not as pretty, but whatever works, right?

In the end, I was pretty pleased with the final result.

Its inaugural run was a batch of sesame seed we had grown for ourselves, and never gotten around to cleaning. It worked like a dream! We caught an excellent video - it really lets you see how the cleaner works to pull of lighter stuff while letting the seeds drop through.