Quote Originally Posted by MartinS View Post
Dean,

For those of us who are learning and planning, could you expand on the above?

Is this 60BYG401-03 https://cnc4you.co.uk/resources/Step...1-03%204Nm.pdf an example of the stepper categorised above? or if you have another preferred source/model, what is it?
Yes those are good motors which I've used many times. The sheet say's it all really When wired in parallel the Inductance is 3.0mh which is a good value. The lower the inductance the better.


Quote Originally Posted by MartinS View Post
Are those different from the above and do they need different drivers?
Yes and No.
Yes they are still a stepper motor but they have encoders built into them.
No because while they are stepper motors the drives they use are more like Servo drives and designed to read the encoder to track the motors rotation.
Normal stepper drive just recieves pulses and tells the motors to rotate but doesn't actually check or know if actually rotated the commanded distance. So for instance if your axis is binding stiff or very heavy you could lose steps and neither the drives or control software(mach3) know anything about it which leads to inaccurate cuts.

Closed loop drives work differently in that they use the Encoder on the motor to check if it rotated the commanded distance. If it over shot or under shot they correct it's position so returns to commanded position. If they over shoot more than programmed distance they will throw a fault message that can be sent to the control software so can stop the cutting.

While they are Not Full Closed loop, meaning they don't feed the motor position back to controller which still takes it on blind faith that commanded position as been reached. They are a good alternative because they do correct for small positional errors inside the drives and warn the controller if large positional errors occur. Compared Standard stepper drives which have no clue where the motor ended up so can not tell the control software if errors occur. The first you know about it is when the job is finished and wrong or worse machine crashes because it's got lost.!!

So in short yes they are different and need special drives, No they are still stepper motors.
Often you buy the closed loop drives and motors together as a set. Like these.
https://www.ebay.co.uk/itm/CNC-Hybri...IAAOSwjlVcIJIb

https://www.ebay.co.uk/itm/NEW-Leads...UAAOSwqFBbvGxS

Hope that helps.