motors on which end of screw

[deannos]

Hi Dean,

The others have answered your Q but one thing you may not know or be aware of is one end should be fixed (the thrust end John refers too) often this end will have a threaded portion.!
This end will usually be clamped thru 2 angular contact bearings mounted into a bearing mount or plate, reason: so the screw doesn't float back n forth effectively causing backlash. The other end just goes into a normal bearing and is referred to as the floating end.

Knowing the machine you intend to build I think you'll find it's not designed to take 2 angular contact bearings like I describe but a single STD bearing. This will work but there could be some end float, you may want to think about making a slight modification so it use's 2 STD bearings with a slight gap between the outer races then when tightened together it preloads the inner race to the outer removing any float. Or buy the more expensive angular contact bearings which are designed to run this way.!!

Cheers

Thanks Jazz,

This makes for some interesting reading, and endfloat is the same as found in crankshafts etc. I do like the simple idea of 2 STD bearings tightened up, but i only nead this on the Z axis as the others will be using bearings etc supplied by Jon.
cheers ,

Dean