Re: rolled ball screws

Torsten,

The rolled screws will need the variability of the "flexible"
coupling. GROUND ballscrews can use a fixed length coupling.

The Mfrs know what they're doing... The preload spring is chosen
based on the anticipated loads you expect to see in your application.
This means that the flex will only happen if you exceed your design
specs (or if you get the wrong screws<G>)

Hope this helps,

Ballendo


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "torsten98001 <torsten@g...>"
<torsten@g...> wrote:
<snip>

> This backing off is just the thing I am talking about.
> If the backlash of a single nut is lets say 0.004 inch
> then backing off the second nut by this amount or more
> would reduce the function of this arangement to be a
> mere damper when movement against the spring exeeds the
> amount of preload.
>
> This will probably result in a nice feel of motion on the
> spindle because the torque of turning will be very constant
> over the entire range of travel even so the effects may be
> elusive.
>
> On the other hand a Fixed position of the two nuts would
> result in a feel that makes any variation in pitch on the
> Screw very noticeable by requiring more torque to overcome.
> But this would allow adjustment to reduce the backlash effectivly
> in both directions to the amount of the largest pitch
> missmatch within the length of the two nuts.
>
> Question is what is most practical under real conditions?
>
> Are the big MFG's of preloaded Nuts "full of it" for insulting
> our intelligence for offering this kind of solution
> Or
> is this the most practical way of doing it?
>
> What is your take on this?
> Thanks