I had a look at the actual production volumes for the mill in question. They moved about 4000 truckloads of pipe last year. That works out to about 22,000 layers of pipe. (22,000cycles). At 200 inches of total travel per cycle that’s 4.4million inches of linear travel per year. I’ll assume the screws can run at 7,000lbs thrust load at 130rpm for the fast and empty return cycle. What formula or curve would I follow to determine loaded speeds with thrust loads from 7,000lbs to 57,000lbs. So that they only have to replace the parts once per year? Based on 2.2 million inches of travel per year with pipe?