Design and Performance of Hold-on Type Sorghum Thresher for High Moisture Content

Abstract Sorghum is a plant with broad adaptability, is resistant to drought, and is very suitable in marginal areas. Sorghum plants contain 7% to 17% seed composition and 83% to 93% leaf stems. At harvest, the moisture content of seeds is 20% to 30%, and the stem is around 76% to 88%. Several stages are carried out after the sorghum harvesting process, and one of them is threshing the sorghum seeds. The threshing of sorghum seeds requires a hold-on threshing machine so seeds can be threshed immediately after harvest, and the stems from sorghum plants can be chopped directly for cattle feed. This study aims to design and test the performance of a hold-on type sorghum threshing machine that can be used to thresh sorghum seeds immediately after harvesting at a grain moisture content of around 20% to 30%. The methods used include problem considerations, the preparation of structural designs, functional designs, manufacturing drawing designs, and manufacturing functional and performance testing. The results of testing the performance of the threshing machine revealed that the working capacity of the machine was affected by rod clamp rotation, the threshing cylinder, and the moisture content of sorghum seeds. The cleanliness level of sorghum seeds is above 90%, while the level of seed damage ranges from 0% to 1%.