Re: Hi I'm new

Jerry,

Thanks for answering, that makes sense to me. If I understand this
correctly, rather then trying to generate pulses directly from my
parallel port, I could buy a controller such as one of these:

http://steppercontrol.com/controllers.html

and that would generate those pulses for me? Their website isn't
exactly clear but I get the impression that my computer would tell
the controller what it wants (to rotate the motor by x amount), and
the controller would generate the pulses to make it happen. Am I
getting it? I thought I understood the driver/controller
relationship, but now I'm a little confused.


--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Carol & Jerry Jankura"
<jerry.jankura@s...> wrote:

> Hi, David:
>
> According to the specs, these motors are rated at 22 oz-in. That's

not very

> much for CNC applications, so I'd probably pass on them.
>
> Now, to answer your question - you can probably use your printer

port to

> drive them.
>
> However, I'd question whether Windows is a good environment and

Visual Basic

> is a suitable tool. My primary concern is the speed at which you

can send

> information to the output port. If you're using a timer component,

you'll

> find that the best granualrity is 1 millisecond (yielding a 1Khz

step rate)

> which is most likely too slow a pulse rate, unless you write your

own

> ring-zero driver to handle actually sending a pulse train to the

motor

> driver.
>
> Windows strength is the ease at which you can create a human

interface. Its

> weakness is real time processing, which is what's required to drive

stepper

> motors. You need two attributes - the ability to send a relatively

fast

> pulse train (8000 - 25000) is reasonable and the ability to send a

robust

> pulse train (i.e. there is little or no jitter in the pulse train).
>
> You might want to try TurboPascal in a DOS environment for your

first

> attempts. Perhaps, you'll work with windows after you get something

working

> in the DOS environment.
>
> -- Jerry
>