Originally Posted by lagfish  hey, even if it gets me just 1 year of service, I'm happy. I can just replace the bearings for $13 a pair in 10 min, rather than spending days preloading high quality bearings costing many times that amount.
Can you also not experimentally determine the preload? For example:
Get a precision spring of a known K value, and place it in between the two bearings you're using and on the same ballscrew.
Using the K value figure out how much deflection of the spring you need for the preload you want.
Tighten the nut with a torque wrench until the desired deflection on the spring is reached.
Note the amount of torque needed, and this should be the amount of torque needed to preload it on the real bearing block |
with that quality of bearing your thinking a little over kill
as long as the bearings run smooth you should be ok