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

Dave,

Ok, The reason for your poor motor performance is you are running it
from a +5VDC supply. Actually it's amazing you are getting the speed
you report at that voltage.

Step motor performance is proportional to voltage, and the maximum
voltage is 20 to 25 times the motor's rated voltage.

The good news is you can reasonably expect 20 times the speed you are
getting now. The bad news is you need a better (read more expensive)
drive that can do that.

Your motor can deliver a lot more than it is doing now. It's the
drive that's not up to the task. There is no reason to consider
servos. The motors you have can do a lot more.

Mariss

--- In CAD_CAM_EDM_DRO@y..., "dave_ace_me" <davemucha@j...> wrote:
> 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!
> > > > >