Design and Development of an Universal Vacuum Disc Equipped with Hole Adaptors for Precision Seeders

The objective of this study was to design and develop a vacuum disk equipped with hole adaptors for precision seeding of different crop seeds. In order to meet this objective, a vacuum plate with a pitch diameter of 190 mm and with 36 holes, each in the diameter of 8 mm was designed and manufactured.  What makes the disk for using different crops was the idea of adjusting hole diameter with different adaptors at different diameters that makes them suitable for seeding different crop seeds. If necessary some of the holes can be plugged and the number of holes on vacuum plate can be reduced proportionally down to 18, 12 holes etc. This would provide another option to the farmers in order to set the theoretical seed spacing along with a change in transmission ratio via gear box available in precision seeders. The adaptors designed in a special software was manufactured on a 3D printer at a hole diameter of 2.5 and 4.0 mm in order to use for seeding cotton and corn seeds, respectively. The adaptors were then plugged on 8 mm holes and tested in the laboratory conditions by using sticky belt test stand. Seed spacing values were measured by a computerized measurement system (CMS) for the cotton and corn seeds. These tests were conducted in order to find out how the use of adaptor materials as coupled with the steel vacuum plate thus changing the coefficient of friction will affect the performance. The theoretical seed spacing for both cotton and corn seeds was set to 11.8 cm and a vacuum of 6.0 kPa was applied during the tests. The forward speed values were selected to be 0.5, 1.0 and 1.5 m s -1 . Quality of feed, multiple and miss indices as well as coefficient of precision (CP3), Precision and E rms were considered as the performance indicators for precision seeding. The quality of feed index for cotton seeds was found to be 84.4 and 88.9% while the miss index contributed to the rest of the seed spacing distribution of 15.6 and 11.1 % at forward speeds of 0.5 and 1.5 ms -1 , respectively. The quality of feed index for cotton was obtained to be 100% at a forward speed of 1.0 ms -1 . The quality of feed index for corn seeds was found to be 100% at all forward speeds considered in the study.