Re: Z axis drive

> Are you sure there isn't a counterballance system hidden in there
> somewhere? A hydraulic counterballance setup for a modest weight

like

> 1,000# can be pretty small and easily hidden.
>
> Without a counterballance system of some sort, any machine with a
> heavy head will cause a massive imballance in the servo load between
> up and down which I would expect would hurt performance.
>
> As someone else noted, without a counterballance the servo could end
> up driving in the up direction to move the head up, and driving in
> the up direction (just less force) to move the head down as the
> weight of the head backdrives the ballscrew.
>
> Pete C.
>

Ok, now I am curious. I will go check and see if indeed there is a
hydraulic cylinder or something that I have not noticed before. I
always assumed the little black box sitting on top of the ballscrew
was some sort of clutch or brake. I will snap a picture, maybe
someone will know from that.