Re: [CAD_CAM_EDM_DRO] 4 phase PM type stepper

In a message dated 02-Jul-01 02:21:25 Central Daylight Time,
cadcamcenter@... writes:

> MOTOR SPECIFICATIONS:
> No. of phase : 4 phase PM Type (pulse modulation?) >>

NO! "Permanent Magnet"

> Step angle : 7.5deg+-5%
> voltage : 5
> winding resis: 70 ohm
> winding induc: 30mH (1Vrms 1kHz)
> start pulse rate: 600pps
> slew pulse rate: 610pps
> holding torque : 180g-cm
> no. of wires : 6
> QUESTIONS:
>
> What is the difference between 2 phase and 4 phase steppers? >>

"2 phase" means two windings, usually only two wires, each. "4 phase" is
actually the same, except THREE wires per winding, and the center-tap is
"common" and the outer-two "ends" of each winding (four in all) are
alternatly energized, magnetically the same as "2 phase". But as only half
the copper is in-use at any instant, it is inefficient, obsolete, cheaper,
and simpler to build drivers "at home", but if $ not a factor, go for bipolar
("2 phase")!

> Are 7.5 deg. steppers good enough for CNC work? >>

Probably not! Depends on what is being "CNC'ed"! Think in terms of 1.8° or
better!

> What is starting/slewing pulse rate? What significance does it have for
> motor- controller? >>

I leave this one to someone who can read and do basic math.

> 1g-cm = ??? oz-in (sorry, but someone on the list will be able to do this
> conversion without having to hunt for conversion tables) >>

Ditto

> Will the motor be compatible with those CCED motor controllers
> (gecko, camtronics, etc.) >>

DOUBLE-Ditto ! ! !

>
>

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