From: muratlanne@gmail.com   
      
   "Richard Smith"  wrote in message news:m1cydnvf9q.fsf@void.com...   
      
   I've seen videos of "artisanal" gold mining operations in South America.   
   The videos are/were motivated by trying to find an alternative to using   
   mercury to extract the gold, but anyway...   
   They show sheds with cast concrete mountings for lines of ball-mills -   
   drums about 800mm diameter.  Drive is from a line-shaft by belts running   
   one to each mill.  The mill is on an axial axle, so not suspended from   
   the belt.   
   For what it's worth...   
      
   --------------------------------   
   The only reason I suggested suspending the drum from the belt is to minimize   
   shaft and bearing requirements since you are limited without a metal lathe,   
   as I once was.   
      
   There is special concrete for mounting machinery:   
   https://unisorb.com/tech_info/literature/recommendations-for-gro   
   ting-machinery.pdf   
      
   My after-school job was in a leather belt factory with overhead line shafts   
   driving the older machinery. They were attempting to replace leather with   
   synthetics such as Nylon-reinforced Urethane but leather is so good for some   
   uses that it was difficult to improve on.   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)