Re: uh, Mariss, can you clear up my confusion ?

Where to start....

I know I have been making a lot of mistakes so
understand I am near the bottom of the hole
in the pit under the ditch at the
bottom of the slope up the learning curve.

I am using an e-bay stepper controller
uni-polar, running at 5 volts from a PC power supply.
(first mistake) (OK, first and second mistakes)

I can run 300 steps/sec without a problem
and start to mis-step at 350 steps/sec.

Since I am currently using a drill press
and just completing my lead screw mounting
I can only speak to the motor/controller.
(I's send a pic, but haven't figured out how
to post it in messages.)

Drilling a 3/16 hole in 1/4 steel plate
will miss step if I try to take more than
20 steps per peck into the metal.
16 tooth XL drive pully 60 tooth driven.

My real need is 3/64 in aluminum so
this is not a problem, just testing.

The speed limitation is just from moving the
stepper on a bench, unloaded. I am more
than willing to accept it is a limitation
of the drive. PIC micro on the serial
com port connected driver board.

regarding CPU, windoz 98 SE on a Compac 486-66
and also on an AMD 800.

The Stepper is a VEXTA 2 Phase, 6 wire uni-polar
5.4 volt 1.5 amp NEMA 23, does the same on both
my motors, one is a cube, about 2.5 inches long
the other is about 4.5 inches long.
The (longer) one I am using is a PY7 series.

for proof of concept, I am getting ready to use
a 1/2-13 rod, but want to use a 10 TPI acme
once I get the bugs worked out. I assume a
0.9 deg/step on 10 TPI will get me close to
a 0.001" positional accuracy. Theoretically
it comes out to about 0.0005 per step.

One benefit I have is that my drive will not
be under any load as it will move the table
between drilling operations and not
any cutting operations.

Do I anticipate the answer is getting a
'real' stepper controller ?

Dave

--- In CAD_CAM_EDM_DRO@y..., "mariss92705" <mariss92705@y...> wrote:
> Dave,
>
> Good evening! I think you are mixing apples and oranges here. It is
> coincidence my example speed and yours are similar. I was thinking
> about your problem when I read your original post but did not
address
> it because I needed more info. So here goes:
>
> (1) What is your leadscrew turns per inch?
> (2) What is your power supply voltage for the drives?
> (3) What type drives are you using? Full-Step? Bipolar?
> (4) What is the maximum speed you get before stalling?
> (5) Is the motor under load at the time?
> (6) What is your CPU speed?
> (7) What is your motor frame size? 6-wire? rated phase current?
> (8) What is your leadscrew diameter?
>
> I have a hunch the reason for your problem will be simple and you
> will be able to get much more speed than now.
>
> Mariss
>
> --- In CAD_CAM_EDM_DRO@y..., "dave_ace_me" <davemucha@j...> wrote:
> > from post: 39596 Subject: Re: Gecko G201
> >
> > <sinp> (1) A full step drive needs 200 pulses to
> > > turn 1 rev. A 10 uStep drive needs 2000.
> > > A full step drive needs 4,000 step pulses per
> > > second to turn a motor at 1,200 RPM, while
> > > the 10 uStep drive needs 40,000 for the
> > > same speed. Many cannot come up with the
> > > higher step pulse frequency. <big snip>
> >
> >
> > I was hoping I could get 4,000 steps per
> > second on a standard stepper, alas,
> > I knew that was too much to hope for.
> >
> > then <snip> > Maximum speed at 250 oz-in is
> > > 360 full steps per second. On a 10 TPI
> > > leadscrew this is an agonizingly slow 10.8 IPM.
> > >
> >
> > this is more in what I had experienced,
> > (actually 300 steps per second)
> >
> > Since I want to drive a 120 inch long lead screw,
> > am I screwed ? that is roughly 12 minutes for a
> > 10 ft travel. or if use a 0.9 deg per step,
> > that would double to just over 23 minutes.
> > now that is truly agonizing !
> >
> > what is a good solution ?
> >
> > How fast can you spin a servo ?
> >
> > Dave
> > (wishing the laws of physics didn't apply
> > to those of us in New Jersey)
> >
> >
> >
> >
> >
> >
> >
> >
> >
> >
> > > Mariss
> > >
> > > --- In CAD_CAM_EDM_DRO@y..., "rsgoldner" <rgoldner@i...> wrote:
> > > > Mariss, is this right? Given my three motors at 3V/4A phase
> > driven
> > > > by G201s do I need about 60V at 10A or 60V at 2A? Big
> difference
> > in
> > > > cost!
> > > >