Some excellent comments from others here on slab saw
I have 9 saws, I think, from 4" on up to 5 feet. the three largest
are 18" and 24" rotary diamond saws, the largest ( and slowest, and
ugliest) is a 5' long drag saw.
With the larger saws, it is almost a necessity to either become a
machinist for maintenance, or know a machine shop.
where are you located? perhaps we can work some kind of trade.
Mark Zirinsky, Denver, CO USA