Braegan, Emily, Achyut, Marissa will focus on coming up with a method to incorporate winnowing into the thresher.

Braegan and Achyut are beginning their research, brainstorming and preliminary construction on a fan to blow away florets from the grain.

Emily and Marissa are researching winnowing techniques for all kinds of grains and even beans and eventually seek to build a shallow basket with mechanization to shake and shift the basket to separate and jostle the millet in order for the fan to be most effective.

For the Friday People:
Most of the fan is done. Here's where it is:
The pulley was too small to attach to the wheel, so it has been bolted on to this wood. The metal things with the screws through them are welded to the pulley on both sides. I think the weld was done well enough that the band will still fit through the pulley, but if not it should be OK to scrape off some of the metal blobs on the top side. There is more welding on the bottom.















The blades and the wooden thing need to be attached like this. Unfortunately, I didn't get this part done. It should be possible to put some of those little metal hooks (near the screw bins) around the spokes. That is the easiest way I can think of to do it.
















These two wooden blocks will probably make a good base. The fan could sit on a metal rod where the blue line is. We've got a threaded metal rod already, but it isn't the best size (slightly smaller than hole). It would be better to have a new rod, but the one we've got will probably do well enough.


















This is how the rod goes through the non-wheel part of the fan. This is just a bearing in a piece of pipe. The pipe is riveted to the blades. The whole thing is slightly off centered. That wasn't planned, but on the bright side, it may add a little bit of gusting.

The bearing can move around a bit in the pipe. I don't think it will come out, if it does then you can just stick it back in. Once the rod is through the bearing it should be impossible for the bearing to come out.














This is how the rod goes through the whole thing (minus the pulley).
If it is operating properly, the blades, wheel, wood part, and pulley should be what spins. The rod stays stationary.


































Also, Achyut said he may some in tonight after his classes are done to look at it, so it may have progressed a bit.
Good luck, sorry I can't make it (I've got to hand in some projects that determine whether or not I pass a class).

Braegan







Past:

Our first plan was simply to build a fan similar to a floor fan. This would blow air over the florets, lifting the lighter chafe and blowing it away. We tried a number of shapes for the blades, but none blew hard enough. Frustrated, we decided to turn the blades completely sideways. This blows the wind quite strongly, but it blows it from the sides of the fan. This actually is closer to the design of a traditional winnowing machine, although we didn't know it at the time. We've decided to go with this design.

Present:

Currently, we are building the sideways fan out of steel. It will be attached to an aluminum bike wheel. Because aluminum is difficult to weld, it will be attached with rivets.

Future:

We still need to see how the fan will interact with the whole system. In a classical winnowing machine the fan is covered. In our tests we could not get the covered fan to push very much wind. Currently, we do not plan on using a cover.