Farmer Built Spelt Dehuller
The goal of my project is to design a spelt dehuller that could be built and used by any small farmer. The spelt dehuller will use a rotary screen with a grating/ peeling/ sizing action common to the German style dehullers but scaled down for the smaller farmer. The unit will also feature a simple aspirator to remove the free hulls.
Weatherbury Farm is a diversified small farm. Since 1986 we have had a cow-calf and lamb operation which we transformed in 2006 into a grass-fed beef and lamb operation where everything is sold directly to the consumer. In 2008 we started growing certified organic grains, largely so we could use the straw to bed the animals in the winter. We grow hard and soft wheat; rye, hull-less oats, spelt, open pollinated corn, and emmer. Last year we grew buckwheat for the first time. Currently our grain production is sold as milling grade grain and used to feed our chickens. In 2011 we purchased a stone mill with plans to sell whole grains, flour, and rolled products directly to the consumer. By mid-spring 2012 we should have all of our permits in place which will allow us to mill our grains and sell them directly to customers. Our farm also has a Farm Vacation (Bed & Breakfast on the farm) which we have operated since 1992.
We are currently farming 175 acres. We own 102 acres and farm another ~73 acres on three separate nearby farms. In 2011 we got an additional ~25 acres on the farm of the descendants of the family that started our farm ~180 years ago.
I have been working with Dr. Elizabeth Dyck of the Organic Growers’ Research and Information Sharing Network (who is my advisor on this project), formerly with the NOFA-NY Northeast Organic Wheat Project. For the past two years she has been doing field trials of emmer on our farm. When I am finished she will also help to disseminate information about the spelt dehuller through the many workshops she puts on.
In 2011 she connected me with a group of engineering students at Cornell who were looking at building a spelt dehuller as a senior engineering project. I have provided information to that group and have also shown one of the Cornell staff members working with the students the preliminary drawings of my spelt dehuller.
I got a late start on this project as I was working on finishing up my previous SARE project late into last year. I designed the spelt dehuller in AutoCAD on one design page so that I could quickly check the fit between parts. I am currently putting the individual parts and assemblies into their own title blocks.
I have designed the spelt dehuller in CAD. I have tried to keep it a clean design with a minimum of parts. I have also designed the dehuller so that I can build different interchangeable attachments at a later date. We had a very wet year which hindered the completion of my previous project and thus the commencement of this spelt dehuller project.
I have modified the drive system slightly from my original proposal. Instead of a jack shaft and pulleys to transfer the motors drive into the hulling chamber I have decided to go with a direct drive motor and a variable speed drive. The hammers in the hulling chamber will be mounted on a hub that is directly on the motors drive shaft. This setup greatly reduces the number of parts in the dehuller and also eliminates a belt which could potentially slip.
Since I will be slowing the motor down with the variable speed drive instead of using pulleys some of the motors rated horsepower will be lost. I upgraded the motor from a 7 ½hp motor to a 10hp motor which use the same bolt pattern and drive shaft size. When the dehuller is operational, I will be able to measure the amperage draw of the motor to determine if a 7 1/2hp motor could also be used with the same design. I felt it was better to have a little extra power that not enough.
Soon I will begin fabrication of the dehuller. Once the dehuller is built I will debug and experiment with different screen sizes and operational settings to optimize the dehuller’s operation.