This video shows you how to set the gap on an over-driven cone mill machine.
Here the operator starts by placing an X spacer onto the shaft, then closes the outlet shroud (ensure this is properly and fully fastened, otherwise this will affect the accuracy of your setting). In this instance, when the operator turns the belt you can hear a scraping noise. This means that the impeller has dropped too low, and is rubbing on the screen.
Next, the operator selects a reduced spacer arrangement, with a total of Xmm spacers, moving the impeller further away from the screen. This time there is no ticking noise when the belt is turned, indicating there is now clearance between the screen and impeller.
In this scenario, there is only one more available spacer, 4mm. Once installed, if there is no rubbing noise, this spacer is giving the closest possible gap between the screen and impeller. If it does rub, we simply go back to the previous spacer (which did not rub) in the knowledge that this would be giving the closest possible gap. Once installed, the 4mm spacer does not rub, therefore we have an optimum gap between screen and impeller. Simply replace the belt cover and the machine is ready to run.
Video