Understood. Your situation may be similar to ours; setup dependent, short run, multitude of seldom run part numbers.
Use the address below. This is the MathDL page for Excel based calculation and graph of the hypergeometric sample size. Very easy to use, but not exactly what you need...
Is the historical data PASS/FAIL or is there a variable result with limit(s).
Tried DOE or ANOVA to determine cause and correlation to multiple failures?
Is my problem solved?
Rather than have another $6000.00 service charge (yes, that's thousand) with little effect I disassembled this sucker myself. As previously stated sll bearings and rails were in excellent condition. The stops were straight and solid. BUT the stops were where our "bearing...
Each bearing assemby (there are left and right) consists of 4 rails and one bearing strip. The rails are contained in a groove in the stationary member and a similar arrangement in the sliding member. The bearing carrier is a plastic strip with 10 holes, 10 balls. The balls are held in place...
I have the assembly apart and in the office. Rails look new. Bearings and carrier like new. Lots of grease. Stops at each end are straight and solid. Load is very light. Motion is manual and generally very slow. Some fast retract/extend, but never continues to the stop.
Considering...
Only accumulated use. Rails and bearings were replaced by manufacturer's rep. less than one year ago. Lasted, well, didn't last... Nothing looks amiss, nothing looks missing. But bearing carrier jumps over end stops.
We have a piece of equipment having two bearing sets of 4 rails with a strip of individual balls. Worked fine for years. Has been a pain for the last three ! At each end of 2 rails is a roll pin stop. The strip of bearings is overrunnng the stops at either end. There is no obvious visual...
