Re: [CAD_CAM_EDM_DRO] Re: Does control s/w affect machine performance? max step rate

turbulatordude wrote:

>--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Fred Smith" <imserv@v...>
>wrote:
>
>
>>--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
>><davemucha@j...> wrote:
>>
>>
>>>>100 ipm then is 2000 steps/rev * 33.33 rev/second =66,660 steps
>>>>
>>>>
>>per
>>
>>
>>>>second
>>>>
>>>>
>>>33.33 times 60 = almost 2,000 RPM.
>>>
>>>Wear on the nut will increase at those speeds. 1/2-20 is not the
>>>typical choce for high accuracy, not longevity.
>>>
>>>
>>red herring and not pertinent to the discussion
>>
>>
>
>
>What I am talking about is the need for the speed of steps in the
>first place. That is completely pertanant to the discussion of why ?
>
>
>
>

Well, there are several reasons. Some people are building huge routers,
that need
to move very fast. Some people are using step/dir servo drives like the
Gecko 320,
and have high resolution encoders, either by choice or accident of what
they can
grab on eBay. With the servo drives, there is no upper limit on step
rates, and the
positioning accuracy will be much greater than a stepper can provide.
Anders Blix has been having a terrible time with EMC, but we finally
found his problem.
The big one was a switch in the wrong position. But, he is running his
step/dir
servo drives at 300,000 steps/second. I don't know what his resolution
is, but
obviously, it is quite high. So, he certainly needs more speed than
software-generated
steps will do for the forseeable future.

Jon