Starting out with motors, pulleys and belts

Other Hardware Motors, Mechanics, Power and CNC
1

Im looking for a bit of help finding and choosing the correct motor, pulley and belt for my project.

I’m making an automated door unlocker, which Im attempting to do without damaging the door (it is a rented property!)

I am lucky enough to have a front door where I am able to lock and unlock the door by twirling a thick dial clockwise or anticlockwise. It is about 2.5inches in diameter, about 1 inch in depth, with about a 35 degree angle between the lock clicking into the lock and unlock space. It doesn’t require much effort to move.

My plan is to connect a belt to a pulley attached to a motor or a servo so I can control the rotation pretty easily.

I have no idea about pulleys and belts and in particular motors and how they are fixed and what I should be looking for. Can someone recommend me some kind of components suitable for this project so I can go about purchasing something suitable?

This forum has always been an endless source of knowledge for my venture into electronics, so thank you in advance :slight_smile:

2

#1 rule of Motors and pulleys. Large pulley on motor, small pulley on load - load moves fast, little torque. Small pulley on Motor, Large pulley on load, load moves slow, lots of torque.

3

Servo sounds so much easier. They're made for that type of movement. No limit switches needed and the coding and physical mounting is easier. Since it's only 35 degrees or so of movement needed, the ability to allow for manual operation would be easier too. - Scotty

4

You should be able to make a setup using a servo to turn the latch. Use velcro to mount the servo on the door so you can just rip it off the door in ase you have a fire or such.