[Nilesh]

hello experts,
my stepper motor knowledge is limited i read in the forum but not able to understand properly !!!

- what is UNipolar and bi-polar difference , which is better in quality and durability now a days ??

- what is single phase and double phase stepper motor , also i see stepper driver specs. also mention this , i don't under stand this term.

- some stepper motor with encoder for better position contorl , is this really good for quality CNC build than regular stepper driver ??

can anybody help me to understand this term.

help appriciated...thanks in advance

[wizard]

Try searching for stepper motor theory on the net, here are just a couple of links:

1. Stepper Motor Theory
2. Stepper Motor Theory of Operation - Developer Zone - National Instruments
3. Jones on Stepping Motors
4. Stepping Motors , step motor , stepper motor theory
5. Stepperworld Tutorials

These are just a few sources of info and go a long way to introducing stepper motors to somebody. More importantly they have pictures and schematics that go a very very long way to helping with what is going on in the can. Without those drawings and pics it is very hard to get some concepts across.

Hope these links help.

[Nilesh]

thanks,
very helpful for person like me

thanks again

[CISZEWSKI]

Hello Nilesh
I'm no expert, but watching this video helped me to understand how they work.
[ame="http://http://www.youtube.com/watch?v=QPYRuX28SyY"]http://http://www.youtube.com/watch?v=QPYRuX28SyY[/ame]

[hoikay]

hello experts,
my stepper motor knowledge is limited i read in the forum but not able to understand properly !!!

- what is UNipolar and bi-polar difference , which is better in quality and durability now a days ??

- what is single phase and double phase stepper motor , also i see stepper driver specs. also mention this , i don't under stand this term.

- some stepper motor with encoder for better position contorl , is this really good for quality CNC build than regular stepper driver ??

can anybody help me to understand this term.

help appriciated...thanks in advance

1.Bipolar:have two coils,four lines,current can be forward and reverse flow in the two coils,so called bipolar;
Unipolar:have two coils,five or six lines,current go a different direction in half of a coil,only used half of a coil;
Bipolar have a higher efficiency of application than unipolar.

2.Single-phase motor usually refers to use single phase ac power supply (AC220V) power supply of small power single-phase asynchronous motor.
I never heard double phase stepper motor！there have three phase stepper motor.

3.Yes,add a encoder to the machine as a position feedbakc closed to the motion controller,But this proposal will be charged much.Actually, it's hard to add the encoder to the stepper motor by yourself if you are not motor manufacturer for the airproof reason.
Another way, you can use a existing closed loop stepper system (closed loop drive+motor) as a directly replacement of the current system. It combines the advantages of both servo system and open loop stepper. And it's cheaper than servo system. You can go to Leadshine website to get more product information. Leadshine closed loop stepper products are named as Hybrid Servo Drives and Hybrid Servo Motors.