Motor for turning a door lock?

Never actually used a motor but I want to use an arduino to unlock my door (key fob + motor + arduino = keyless entry into my room!). I just don't know what kind of motor, size, power, etc., I would need.

The motor will be mounted about 18 inches from the lock, so I'll have a 3d printed gear that goes around the lock, a gear on the motor, and a rubber belt that connects them (hopefully it works). Could someone recommend a motor that would get the job done?

My first thought for a job like that is a servo - assuming the lock does not need to be rotated more that 180 degrees. Probably no need for 3D printing or belts etc. And if more motion is needed a sail winch servo may be the answer. Servos have position detection built in as standard.

How much force - gm.cm or kg.cm - is required to turn the lock mechanism.

If you do not propose to use a servo how do you propose to detect the position of the motor so that you don't drive it too far and break something?

...R

It would be much easier to replace the existing lock with an electromechanical lock. That way the motor and gears are ready to go.

http://www.homedepot.com/b/Hardware-Door-Knobs-Hardware-Electronic-Door-Locks-Electronic-Deadbolts/N-5yc1vZc29l?Ns=P_REP_PRC_MODE|0

Hi, I wonder how easy it might be to hack one of the $50 class locks to interface with external/arduino??

Like:

...don't want to add 10 solenoids to push the buttons..

jremington:
It would be much easier to replace the existing lock with an electromechanical lock. That way the motor and gears are ready to go.

http://www.homedepot.com/b/Hardware-Door-Knobs-Hardware-Electronic-Door-Locks-Electronic-Deadbolts/N-5yc1vZc29l?Ns=P_REP_PRC_MODE|0

Actually, it would be easier to just keep using my key, then I don't have to do anything. But what's the point of that?

Thank you @Robin2 for the suggestion on the servo. I'll buy a couple and give them a try.

What's the point of using "easier" when the whole point of doing something like this is to have fun and see if you can do it?

The hard part will be the electromechanical part, and that has nothing to do with Arduino.

How are your machining skills?

What "electromechanical"? I think you're making this way more complicated than it needs to be.

Motor will be mounted above the dead bolt, gear will be 3d printed so that it slides over the deadbolt knob, a gear attached to the motor, and then both connected using a belt.

What "electromechanical"?

A motor is electromechanical, and will be connected to mechanical parts.

Sounds like you will have an easy time of this project!

InunoTaishou:
I think you're making this way more complicated than it needs to be.

Motor will be mounted above the dead bolt, gear will be 3d printed so that it slides over the deadbolt knob, a gear attached to the motor, and then both connected using a belt.

He's not the only one :slight_smile:

...R

Downloading stl files and buying a belt is complicated? Shit, how long was I asleep last night?

Be sure to post photos of your finished, working setup.

This is only related to the op question, but in Germany such a door unlocker will void any household insurance ...