Re: Why is the push to such high step rates (Grex and Arc100)?

Here is my two pence:


I don't think there is a peeing contest as such, I've never heard
anyone say there system is better than another because it has a high
pulse rate. To hear a system has 20Mhz rates however means I can
relax, no need to worry on that front.

Here is another thing, The performance of mach3 varies with your PC,
in the same way as PC game performance varies with PC but the console
users all get identical performance. Things like the G-rex provide
what they provide every time and give amazing overhead, they do this
while allowing you to skype or surf on your PC.

In terms of high pulse rates they interest me on several fronts, one
is on the use of linear motors and encoders, they go very fast indeed
and pulse rates can be very high, at least beyond Mach if not up to
the multiple Mhz rates. Along with linear motors there are belt drive
systems that could also use linear encoders, US digital have encoder
strips that are getting to decent resolutions and that solution seems
to work very well in the my HP printer. Its low force stuff not
milling but they are applications, I know there are many people here
who would like to build rapid prototypers for example.

Parallel kinematics for which I have a thing for shares load between
motors meaning that the speeds can generally be higher. To allow for
the variability of resolution in the work space it may be good to have
higher resolution encoding than you might other wise have. It also
opens the potential door for pulse-post-processing. A name I made up,
rather than do the kinematics in the controller you have a processor
that takes in the pulses and translates them according to the
quadratics for the machine. I always wanted to do this but you need
to have more pulses in then you intend to chuck out so for a given
pulse rate out you need high pulses in.

I think your overall message is valid, yes people don't get hung up on
the pulse rates. BUT there are applications where they can be useful
and not everyone wants to do things within the normal realm of home CNC.

Graham