We had to pull out the welder a few weeks back, as we deliver barley direct to the malt house in Nairobi we had to build a screen, I could not buy slotted screens and so I went to the industrial area and bought eight 2 meters by 1m 3mm round hole screens, I had a engineering shop weld two sheets end to end and then they rolled them as we do not have the gear to do this. We then built the drive, installed internal spokes and baffles to retard the grain flow and to maximize the screen area that makes contact with the grain, we borrowed the hyd motor off our sprayer and the loading auger off the simplicity air seeder,these both run of the tractor hydraulics.
After a number of modifications it worked well, we are removing about 1 to 2% by weight, the retention (amount of barley above a 2.2mm screen is running at 97 to 98%) which considering the below average rain in crop is good.
We also last week put a aspiration system on which consists of the hyd driver fan off our simplicity air seeder and a snazzy manifold we built that helps the light material to be sucked off as it enters the screen.