Farmer-built compost turner with hydraulic drive

Project Goal:

To develop a cost-effective turner that will use the tractor’s remote hydraulics to power hydraulic motors on the turner and achieve the desired ground speed. The design of the turner will be such that a farmer can build it in their workshop.

Farm Profile:

Weatherbury Farm is a family operated 102 acre beef and sheep farm. In 2007 we began direct marketing grass-fed beef and in 2008 we added grass-fed lamb. Currently we have 24 cows, 8 heifers, 22 calves, and 20 ewes. In 2008 we took on another 35 acre farm which is all cropland. In the fall of 2008 we planted 10 acres each of soft red wheat and rye which we harvested as certified organic grain. In 2009 we harvested our first certified organic grains (10 acres soft red wheat, 10 acres rye, 1 acre hulless oats, and 1 acre open pollinated corn). In 2009 we also took on another 20 acres of fields. For the 2009-2010 crop season we are adding hard red wheat, spelt, spring wheat, emmer and einkorn. In 2011we took on another 25 acre farm and added buckwheat to our list of crops.

Technical Advisor Input:

My technical advisor , John Hewitt, works with the local conservation district and will be helping me with the nutrient management aspects of the project now that I have the compost turner built and am composting.

Project Activities

For this project, I first drafted all of the blueprints for my compost turner in CAD. Then I fabricated the subassemblies for the compost turner. I was able to utilize my CAD drawings to have my steel supplier CNC plasma cut out the different plate profiles giving me parts that were ready to assemble. I did almost all of the machining in my small on farm machine shop. I sand blasted all of the parts prior to spray painting them with automotive grade paint. Many of my neighbors who have seen machine up close are amazed at how professional it looks.

This project took a lot longer than I originally anticipated. Also as this project transformed from the simple sketches that I used to figure out my grant application to a finished machine some parts of the machine grew in complexity. The most notable example is the hydrostatic drive which grew from a concept involving 4 parts per side to a functioning system involving 12 parts per side.

Conditions

Since I have finished my compost turner it has done nothing but rain (or so it seems). I have tested the compost turner out using my 4WD tractor with a CVT transmission turning nearly 300 feet of windrows 3 times. I used the CVT tractor to test the turner since the original hydrostatic drive pivot bracket didn’t have enough rigidity and had to be revised. The original bracket would twist slightly and allow the hydraulically driven sprocket to jump out of the chain in the wheel rims. I made the new bracket that is twice as thick and will fix this problem 3 weeks ago but it has been too muddy to try it out. Once the drive design is perfected any changes will be made to the plans online to reflect the most current design.

Economics

In my grant, the materials were budgeted at $6,572; the materials actually cost $12,500. Inflation of nearly all raw material costs contributed substantially to the overall increase in cost. This increase was also due to the fact that my turner design ended up being more complex than the pre-grant sketch on paper. (I continued to look at commercially built turners, attend seminars and read articles during the time I designed the turner.) When designing the machine in Auto Cad, I realized that the simple hydrostatic drive system on my paper sketch had to be more complex to function in reality. I also incorporated several CNC plasma cut pieces of steel plate into the design, which increased the cost but drastically reduced the skill level needed to build the machine.

The Sittler 509 compost turner with hydraulic assist (the commercial machine closest to the one I built for the grant) cost $28,850 when the grant was submitted and costs $33,100 today. As initially submitted, the savings were $22,278; the turner as finally designed still has a savings of $20,600 savings with a superior design and is still definitely worth a farmer’s time to build.

Assessment

In this project I constructed a farmer built compost turner that will allow me to produce compost efficiently. Specialty farm equipment is often very expensive and this project could be used as a stepping stone for other farmers to build the specialty equipment they need for their operation. If a farmer has the time to build their own specialty equipment he/she could realize a substantial economic savings.

Adoption

Composting is the cornerstone of nutrient management for our farm. The compost turner I built in this project allows me to produce the compost in a timely fashion. The project has also had an interesting side effect; as people have seen my windrows of compost they have been approaching me about taking the excess manure that they have.

Outreach

The plans and construction manual are available online at:
http://www. weatherburyfarm.com/compostturner.htm . As I make further refinements to the design of my compost turner, the plans online will be updated to reflect the most current design.

On October 17, 2011, I presented the results of my Farmer Grant project to 35 farmers and agricultural service providers as part of the Pennsylvania Association for Sustainable Agriculture field day "Innovative Farmers: Finding creative solutions to common problems" in York County, Pennsylvania.  The presentation included a video of the machine in action and a picture board.

Once the hydrostatic drive is perfected I will write an article for the County Conservation District Newsletter and the PSU Extension Newsletter.

In 2012 a PASA field day on composting at my farm has been tentatively scheduled and the compost turner will be key feature of the event.