re:acceleration, was:Re: Another router video..

Most NEMA-23 motors can easily deliver 50 to 80 Watts mechanical. The
drive used was a stock-standard G201. The motor I used in the test
(MCG IH230014) delivers:

24VDC 51W @ 3,000RPM (23 in-oz @ 3,000RPM)
48VDC 109W @ 3,0000RPM (49 in-oz @ 3,000RPM)
72VDC 164W @ 3,000RPM (74 in-oz @ 3,000RPM)

The "thrust" on the screw (1-TPI) was respectively:

24VDC 9lbs @ 3,000IPM
48VDC 19lbs @ 3,000IPM
72VDC 29lbs @ 3,000IPM

The purpose of the test was a 1st try to see how the adaptive servo
algorithm firmware (unstallable stepper project) functions. It was
detuned in these results; tuning it to motor limits should
considerably increase performance. Maybe double the "jacked up"
values.

I took the video. This weekend I'll convert it to a postable MPEG4
(DivX) format.

Mariss




--- In CAD_CAM_EDM_DRO@yahoogroups.com, "Elliot Burke" <elliot@...>
wrote:

>
> Mariss,
> It would be interesting to know how much power the stepper motor

can supply.

> Given your numbers below, if more weight were added to the stage to

slow

> down the acceleration and the same values measured, the motor power

should

> be easily determined. This would be assuming that the motor is

producing

> the same amount of power with each of the two load masses. Maybe

it would

> be better to measure the times with more than two different loads.
>
> High speed video is expensive, maybe an LED on the stage could be

made to

> flash at 1 kHz or so and a single image with a still camera. If

you pan the

> camera perpendicularly to the stage motion for several cycles of

motion, it

> might make a really pretty picture.
>
> The "parallemic triaglide" type stages
> http://www.parallemic.org/Reviews/Review002.html have been claimed

to have

> up to 50 g acceleration. If this could be maintained for 17

seconds, it

> could be used to hurl something into orbit.
>
> 17 seconds * 50 g * 32 ft/s^2 *3600/5280 (seconds/hr)/(ft/mile) =

18545

> miles/hour.
>
> regards-
> Elliot
>
>
>
> Date: Fri Jun 2, 2006 1:57 pm (PDT)
> From: "Mariss Freimanis" mariss92705@...
> Subject: acceleration, was:Re: Another router video..
>
>
> Well, I jacked it up a little:
>
> Velocity: 65.535" per second or 1.664 meters per second
> Motor speed: 3,932 RPM
> Accel time: 0.0853 seconds
> Accel rate: 2 G
> Distance moved: 20.000" or 0.508 meters
> Move time: 0.392 seconds
> Avg velocity: 51.02" per second or 1.296 meters per second
> Avg motor speed: 3,061 RPM
> Out and back time: 0.784 seconds
>
> This will be a very short video.:-)
>
> Mariss
>
>
> --- In CAD_CAM_EDM_DRO@yahoogroups.com, "Elliot Burke" <elliot@>
> wrote:
> >
> > Marliss,
> > Just for fun I ran these numbers on your motor:
> > top speed 50 inches/second
> > travel 24 inches
> > time 0.5 second
> > Assuming constant acceleration up to 50 inches/second, then
> constant speed
> > after that, two equations can be written:
> > 1/2 a t^2 + 50(1/2-t) = 24 and a t = 50.
> >
> > Solving these simultaneously gives a = 1250 inches/second^2 and t
> = .04
> > second.
> > 1250 inches/second^2 is about 3 g. So the motor accelerates for

40

> ms at 3
> > g and then coasts at constant speed for the remaining 460 ms.
> >
> > If the size of the screw and the mass of the stage it was moving
> were known,
> > it would be easy to calculate how much power was being applied by
> the motor.
> > This would say something about the efficiency of the drive if the
> input
> > power were known.
> >
> > If you kept the acceleration constant at 1250 inches/second^2, the
> stage
> > would travel the 24" in 200 ms, reaching a velocity of 245
> inches/second or
> > 14700 inches/minute.
> >
> > regards-
> > Elliot
> >
>
>
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