Hi Guys
I have been thinking of designing a set of pre-loaded Ball Nuts for my new CNC Mill project I am working on. What I am planning to use is Rolled Screws and 2 Nuts pushed apart with a spring to remove any clearance between the Nuts and the Screw. I have a couple of questions in regards to this design.
(1) How much pre-load should be on the Nuts? I remember seeing some place the amount of 85lbs. ? This sounds a little high to me? Any idea of the correct pre-load for this set up?
(2) Would the pre-load be different depending on the type of Screw used? (Rolled verses Ground)
(3) If the pressure between your mill cutter and the work becomes more than the pre-load on your Ball Screw, (towards the stationary Ball Nut) you will loose the pre-load on the Screw. Can you have the Screw pre-load high enough to overcome the above with out causing premature Ball Screw wear?
Thanks in advance for your help with my questions.
Regards
Willy