Hello,
i have locker on my door; to lock / unlock it requires 360deg movement. The "strength" is similar to the movement of the key in the locker.

Is there some guideline how to chose a stepping motor for such a use-case?
See the photo of the locker; the white button is the one that has to be rotated 360deg left/right.


Thanks!

 

I would think a small NEMA 17 or even smaller, if geared.
How do you intend to add the stepper motor in respect of the knob?

 

@MaxHeadRoom
thanks will check that motor.
maybe also question: how many Bipolar Torque (oz-in) / holding torque?

How? That would be good question. No idea now - any recco?

thanks!

 

the smallest frame length (thickness) of the motor the better
so what about
https://anaheimautomation.com/stepper/stepper-motors/high-torque-square-stepper-motors/15y/

 

thats what said chatgpt

Typical torque to turn a household key is roughly 40–200 in·oz (0.28–1.41 N·m) depending on lock type and condition.
For planning actuators or motors, pick a driver with 2–3× margin (e.g. a 150–600 in·oz motor for tougher locks)


so assuming 3x margin = 4.23 N-m (600 in-oz)

which sounds like a nonsense

 

or maybe just have to try
nema 15 - 50 in-oz ... if no luck than
nema 17 -111 in-oz

 

Hello,
i have locker on my door; to lock / unlock it requires 360deg movement. The "strength" is similar to the movement of the key in the locker.

Is there some guideline how to chose a stepping motor for such a use-case?
See the photo of the locker; the white button is the one that has to be rotated 360deg left/right.


Thanks!

Going by your image I would get a torque wrench having a dial indicator and turn the lock to get a feel for the required torque you will need and figure a 20% overhead.

Ron

 

@Reloadron thanks
sounds good, but how to attach it to that white button?

assuming that tool looks like this one.

 

You can also rig up a defined length of Cane/Rod and place a spring scale on the end and pull untill it moves the lever, Take a reading.
BTW, if no gearing is involved, i.e. Low motor RPM, you just need to provide the exact voltage for the motor rating to drive it; no driver required .

 

Hi,
By gearing you mean? I
I need to do 360deg movement.


Also that button is install see photo, so question would be if its possible attach motor shaft to it.

Thx

 

Do you still need manual over ride?
If so you could use a double shaft motor/

 

Might be handy, u never know when the control system fail - so u wont be able open door.

 

So double shaft should work!

 

BTW a bipolar motor is preferred.

 

@MaxHeadRoom does the bipolar provide double shaft?
thx

still not sure how to attach the motor to the mentioned button.

 

@Reloadron thanks
sounds good, but how to attach it to that white button?

assuming that tool looks like this one.

View attachment 357832

I would use what I call a "crows Foot Wrench".

Ron

 

@MaxHeadRoom does the bipolar provide double shaft?
thx

still not sure how to attach the motor to the mentioned button.

Maybe look at adapting the operator in Post #10 to the end of the shaft?
You can get double shaft in most sizes, e.g., Bi-polar NEMA17.
A little 8pin picmicro would do the control job very easily, if you were familiar with them.!
or 8825 for control.

What initiates the open/close action, BTW?




8825...........................................

 

I would use what I call a "crows Foot Wrench".

Ron, mind you share a screen - i am getting Access blocked. thx

 

Maybe look at adapting the operator in Post #10 to the end of the shaft?

not sure how?

I need to control one security lock on my door ; open/close.

Controlling wise - ideally able to integrate with home-assistant. .. .so some esp32 or something other?

 

not sure how?
I need to control one security lock on my door ; open/close.
Controlling wise - ideally able to integrate with home-assistant. .. .so some esp32 or something other?

How? In the order of a little mechanical modification/engineering?
Not that familiar with ESP323, but at first glance, seems to be a few aids (modules) out there that may help. ?