[ October 2017 ]
The South Australian Grains Industry Trust is using one of the three test stands to trial the Seed Terminator against a range of crops including Wheat, Canola, Lentils, Beans, Chaff laced with Ryegrass, Broom Grass, Turnip, Prickly Lettuce, Medic, Tares, Wild Radish, Bifora, Bedstraw, Marshmallow and Wild Oats. Early results show Seed Terminator is over performing.
July 2017 Image above is of one of the three test stands: Pitot tube with hot wire anemometer to measure the air flow, torque transducer to measure torque, dustpan and broom to measure kill!
During 2017 harvest there were many learnings and on balance, it was a successful one and a massive leap forward from 2016. The Seed Terminator's beat the living daylights out of billions of weed seeds across the country; 32 machines running successfully across 4 Australian states. Our Farmer Research Partners not only made a real difference to the sustainability of their farms, but they have played a huge part in developing our technology to assist the whole industry.
Our upgraded drive system worked really well, farmers noted that they didn’t notice power draw in canola and barley if the conditions were good. Long green canola straw presented an issue in some areas, if at times too much straw ended up in the mill hoppers. Harvester setup has a role in this, for example an internal chopper on a CASE machine throws straw better than an internal beater. We were able to implement a blockage sensor on one machine which proved quite effective. As the season progressed and the crops dried out, blockage issues disappeared. In the wheat and lupins, engine load was increased over barley and canola. Cutting wheat low to the ground to collect weeds requires a lot of power to thresh. Additionally, wheat produces a lot of chaff on the sieve and can contain a lot of short straw for the mill to process. 35 tonne/hour of wheat produces around 10 tonne/hour of chaff. Lupin pods on the other hand are just tough to process! Our farmers did note that the material coming out of the mill was highly pulverised and volunteer and weed seeds exiting the mill were like flour. This amount of pulverising ensures that there are no escapees in tougher conditions when the moisture is up, or the seeds are smaller, however it comes at a cost of additional load. Lesson 1 from harvest was that there is an opportunity to reduce the amount of pulverisation and the load on harvester.
In the middle stages of harvest, we started to notice that some machines had more mill wear than expected, particularly in sandy soil types. Low cut heights and undulating ground can result in sand entering the harvester and into the mill. Also rain can splash sand onto the lower part of the plant. This effect is so profound that we found nearby farmers cutting the 7-10cm height have twice as much wear as 15-20cm height. Clearly there is another compromise between cut height (and collection of seeds) and mill wear. On some machines, sand also gets sucked through the harvester fan, particularly machines with tracks.
"I have been asked, if the sand is entering the harvester then why isn’t my harvester wearing out? And the answer is all around tip speed. Nothing on the harvester has any where near the tip speed of the rotor which is around 330 km/h. At these speeds sand acts like a sandblaster, biting into the steel."
Lesson 2 from harvest was we need a resistant wear package for sandy regions. At harvest we managed to trial 3 different surface treating options with some good success but a lot to work on.
The harvest finished up and the team went straight to work on reducing power and increasing wear life. A lot of brain storming, some fundamental modelling, and lots (and lots) of prototype testing. In addition to these goals we have continued to develop our drive system. One season of testing is not enough to test long term reliability, so we are using accelerated life testing of components in the off season.
2016 was Seed Terminator's maiden year, the idea of the Multi-stage Hammer Mill was concieved by Dr Nick Berry in June 2016, designed in July 2016 and manufactured in August 2016. A concept that uses the long-held knowledge that hammer mills kill seeds and then splitting that process over three stages to achieve the capacity needed to process the chaff stream of a modern combine harvester. September 2016 saw the promising results of pouring chaff through the mill on a stationery test stand and samples analysed by the Weed Science Research Group, a part of the University of Adelaide confirmed that the Seed Terminator could consistently reduce germination (i.e. seed kill) compared to a control sample by 90% when operated at 2,700rpm.
The Drive System concept was developed to fit across different makes, keeping it as simple as possible with minimal moving parts. CGS Engineers and Nylastex Tooling proceeded to build 9 prototypes on three makes across 4 states in a matter of weeks. The nine prototype trial units were installed on Case (7120, 8010, 8120, 9240), New Holland (CR 8090, CR 9090) and John Deere (9760 STS, 2 x S680). The prototypes were trialed in four states (Western Australia, South Australia, New South Wales and Victoria) across a variety of crops (Wheat, Barley, Canola, Lupins, Oats, Lentils, Faba Beans), soil types and key rainfall zones in the 2016 Harvest.
The season was fortunately a long one as it was a challenging harvest, we were able to try 3 completely different drive systems. The perseverance from all involved was exceptional and enabled us to learn a huge amount and prepare for a massive year of research and development in 2017. The outcome of 2016 harvest was purely we needed a robust drive system. The mill seemed to perform well with a few tweaks needed.