Re: Stepper Motors - output steps

--- In CAD_CAM_EDM_DRO@yahoogroups.com, "turbulatordude"
<davemucha@j...> wrote:

> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "treadlemill"

<ackland@g...>

> wrote:
> > ---I have been playing around with stepper motors in a hobby
> > capacity for several years and have come to the following
> > conclusions.
> > I believe that the difference between series and parallel wound

and

> > wired steppers does not apply when using the parallel port.
> > I have wired 8 lead motors in both series and parallel and timed
> the
> > moves and found no difference. I use new, current rather

expensive

> > microstep drives that req. some switch changes to optimise
> different
> > motor charateristics. Even doubling a 24v supply did not make

the

> > difference that gets discussed about on lists.
> > I do not use my best computer in the basement but after finding
> that
> > there is little difference between timed G00 moves when using an
> old
> > 486/33 and a less old P/133 I did not think using a better

computer

> > would change things too much.
> > I use TCNC which suits me so perhaps there are programs that can
> > output a faster step rate?
> > I could be wrong but I do not think with my setup I get to the

part

> > of the curve where speed and torque drop off occur so there is
> > little point worrying about things like series, parallel,

voltage,

> > inductance and torque reduction. Studying manufacturers specs

seem

> > to qualify this for me.
> > Indexers seem be to used in industrial applications of steppers

so

> > perhaps they can output a step rate where there would be a
> > difference in performance with series or parallel configurations?
> > T
>
>
> In T-CNC you can put in pretty much any step rate you want

although

> the PC may not keep up.
>
> the opening data screen shows the results of a software test.

I've

> put in numbers double that and run one axis without loosing steps.
>
> I have no clue how fast you can go with any reliability, but you
> could easily make a 555 circuit to gernerate some high step rates.
>
> Obviously you need to increase speed until something fails : )

missed

> steps or something.
>
> I'd be interested in your testing.
>
> Dave

I have also noticed that with TCNC the pulse rate can be increased
past the point of making any difference. This only applies to
microstep drives where it seems impossible to get them to stutter
providing the start and acceleration rate is configured correctly.
Previous to this I had been trying to use a then popular 5amp 1/2
step board on 2 projects and found them to be very disappointing. It
was easy to to get them to trip up with TCNC even at low speeds and
the onboard 555 had a very limited range.
I am using a board built on the Allegro 7044 chip to run a small
lathe with great success and have just built an engraving machine
with a Xylotex which was another great buy. I am also using some
Compumotor drives set to 5000 step/rev to drive some larger motors.
The Compumotor drives had their own indexer boards which I removed
so I could use the parallel port for interpolated moves. I do have
some extra drives and when I get time it would be interesting to
leave the indexer in and connect a serial cable and send a few
commands in the Compumotor X language and see what sort of motor
speeds can be obtained.
Looking at motor manufacturers graphs the series and parallel wired
motors are equal up to 1000rpm and only after that does the series
motors start to lose torque. I'm not getting anywhere close to 1000
rpm with the parallel port so I would think all the advice about
series and parallel motors does not really apply?
T