Re: [CAD_CAM_EDM_DRO] CNCing a big surface grinder ?

Kim Lux wrote:

>So do you think that it would be feasible to replace the hydraulic drive
>system with a high speed servo system ? This is quite interesting
>because most of these units even today are hydraulic drive...
>
>

Hydraulic drive for the long feed on a grinder makes a good deal of sense.
Hydraulics can provide nice smooth motion and constant speed without
electronic controls. It is really when doing positioning that the hydraulic
controls get messy. But, on a grinder, there's one axis that feeds
steadily,
and 2 or more that are essentially positioning drives. It certainly doesn't
make a lot of sense to do the positioning axes hydraulically. If you really
want full CNC control, I think the table feed can also be done with servo
motors. Exactly how you do the mechanical side may be a much bigger
decision than how you do the electrical side. You'd need either a linear or
shaft encoder and probably a ball leadscrew. The exact design of the
machine
will have a large bearing on how the mechanical parts fit. I think that
some machines are now using linear motors on one or more axes on
grinders.

If you are just doing surface grinding, it may make no difference, and
you could probably have the computer set the feedrate valves and just
keep the whole hydraulic system. If you are going to try creep-feed
grinding, though, that is a whole different story, as you need high
precision positioning of the table. (I'm no expert on creep-feed, I
just know it is the "new thing" in grinding.)

Jon