Witch stepper motor to choose?

I need an DC stepper motor for operating a door lock. I do not want a "plastic fantastic" motor, but a rigid one that lasts.

Do i need 5v/9v/12v/24v?
And witch motor should i go for?

Bjerknez:
I need an DC stepper motor for operating a door lock.

Why?

Because i allready have a dog......? :cold_sweat:

You want to use a stepper motor, capable of high-precision complex movements like those used in 3D printers and CNC milling machines to operate something needing to move between two positions because... you have a dog.

Bjerknez:
Because i allready have a dog......? :cold_sweat:

WTH? What kind of response is that?

I'm sorry. My answer was not meant to be rude. I need a stepper motor because i want to open and close an animal door from my mobile.

For opening doors, brushed DC motors are far more efficient and easier to control.

Tell us about the animal door, but you might do a bit of searching, because it is a very popular project. "arduino pet door" or "arduino chicken coop" are useful search terms.

Bjerknez:
I'm sorry. My answer was not meant to be rude. I need a stepper motor because i want to open and close an animal door from my mobile.

Apology accepted.

Please clarify: opening and closing the door, or locking and unlocking the door? Opening/closing could be done with an ordinary DC motor, plus a bridge. Locking/unlocking can be done with a solenoid (and maybe a bridge). A "bridge" is a circuit that allows you to switch and also reverse the current to a motor or solenoid to make it move in either direction. Solenoids often have return springs and so do not need to be reversed. But a stepper motor is not the right kind of motor for either of these uses.

But solenoids require time to operate and cannot be moved with just a pulse of current.

Paul

Do solenoids take longer to operate than a motor starting up?

Some solenoids can be operated with a pulse, a reasonably long one, and that's all that's needed to release a catch so a door can be opened.

Solenoids without return springs can be moved to one position with a pulse and returned to the original position with a reverse current pulse. Not that I would suggest that for the door of a bank vault!

Paul_KD7HB:
But solenoids require time to operate and cannot be moved with just a pulse of current.

Use a latching solenoid. The length of the pulse (or the run of the motor) is anyway determined by the Arduino, upon receiving the "open door" or "close door" from the phone.

A servo is another convenient option to move a door, or indeed a lock - depending on the type of lock.

All in all a stepper is not the first choice for this application, unless there's something special about your door that you didn't mention. Well, you didn't really mention anything about the door. Size, required speed to open/close or just unlock so the animal can push it open, or other general parameters and behaviour requirements of this door or its lock (for which there exist many different mechanisms as well).