Thursday, February 26, 2009

Modified roller modules

While Thom was working on the winnower, Jeff updated the roller modules to be more durable, as well as integrated a feed hopper.

We were having issues with the rubber staying glued to the rollers, so the design was modified to accept a rubber tube. We now have a seamless rubber roller that does not move or get caught up in the framework.

The belt drive wheel was moved to the opposite side for user safety, and all of the access points were moved to the front, so you don't have to dissemble the entire system to remove a the field

The feed hopper was integrated into the top of the module, which allows for the same design to be stacked on top of each other to create the 2 pass system. (The metal walls for the hopper are being bent today, so I added them in Photoshop...)

Winnower prototype

Sorry for the delay in posts...Travel, work schedule and the flu have kept me from updating...

Thom built a prototype of the integrated winnower, including a clear front so we could see how everything works. The ramps are adjustable to allow the angles to be tweaked.

Initial test went well, with a few seeds getting stuck on the ramp

A fair amount of chaff made it out of the system

While the seeds dropped down into the bottom

Our only concern is the ability to generate a constant amount of airflow using a hand powered fan attached to the hand crank. We plan to discuss with Erv during his visit this weekend.

Monday, February 9, 2009

Getting Closer...

A few updates from this weekends work...

Attached the natural rubber to the floating roller and passed the millet through 2 times. We are having some trouble getting the sheet rubber to stick to the roller and are going to special order some natural rubber that is formed in tubes, so we can stretch over the rollers and tack down. This should stop the rubber from lifting.

Even with the rubber sheet issues, wrapping the rollers has resulted in a significant reduction in broken grains.

Also mocked up a smaller feed area on the current hopper. This helped even the flow of millet into the rollers.

We are still dialing in the winnower, and need to find the right fan and speed to blow the chaff out of the system. On the left is the raw millet. On the right is the threshed millet after 2 passes and a few fans with a piece of cardboard.

Next steps, in order of importance

1. Wrap rollers with rubber tube
2. Re-build frame from Plywood rather than OSB
3. Integrate winnower
4. Incorporate gears and chain if possible

Sunday, February 8, 2009

Final Concept...

Here is a quick sketch of our final layout. We have split this weeks efforts into 3 areas - Hopper, Winnower and Rollers

Thom will be working this week to integrate a winnower system based on CTI's recommendation. The idea is to make a small fan that blows air across the falling grain, forcing the chaff up and out the side.

Jeff will be working on the roller assemblies, adding rubber sheet to one of the rollers. This decreases the amount of grain breakage significantly

I will be building the hopper. I am using a plastic bin to start, and adding the ability to adjust the feed rate by varying the size of the opening.

The 3 of us worked from each of our homes today, so the images will follow shortly...