Hi,

I'm having some trouble finishing my egg turning mechanism for an incubator.

I've had some help in the past developing a schematics for a 12v motor, but I didn't find a suitable 12v motor with high torque and slow RPM so now I'm trying to solve this problem with another motor, but 220v this time.

The solution I had involved a car windows elevator motor (12v about 60rpm 3A) programmed by a clock that turned every 2 hours. It would turn until it hit a limit switch and stopped until it would turn the other way after 2 hours and so on. The DC polarity would be reversed with some car SPDT relays. I also had some manual buttons to control the turner manually when needed. I have tried to slow down this motor using pulley wheels but i didn't manage to get it solved. Still too fast.

Now i'm trying to implement a 220v motor which I don't know much about. The seller told me it would rotate CW then CCW then CW (etc) every time it would be turned ON/OFF. From what I have read over the internet this can be a bit more random than this. This motor is usually used for barbecues (chicken turner) and rotates at 2RPM. I need this to turn about 1/4 every 60 or 120 mins.

Any suggestions? Thanks in advance!

 

I would suggest that you look for a mechanical solution.
The best way to achieve low RPM and high torque is with reduction gearing.
Depending on what voltage you wish to power the motor, 12VDC or 230VAC, select the motor and add reduction gears.

 

I think the 12v solution would be better if I could solve the gear reduction.

This is the motor I have.

The problem is that this pulley already has about 4cm diameter. For it to work I would have to slow this down to about a max of 12rm (about 5x less), and it would require a wheel too big.

Mechanical gearboxes are very expensive.

 

What is the diameter of the drive shaft on that motor?
The motors I am familiar with have a 10mm shaft diameter.
How difficult is it for you to get a different motor?

You can reduce the RPM by using multiple rear reduction.
Another way is to use a worm gear.

 

The shaft is 8mm

The problem is my incubator is a bit wobbly mechanically. I don't know how I could implement this worm gear in it...

 

You are seeking a full rotation every 4-8 hours.
This is a huge gear reduction. Hence you don't need a powerful motor.
A clock movement is 1 rotation every hour. I would be looking for something similar such as a gear box kit.

 

I would also suggest looking at different solutions.
Instead of running the motor continuously, I would step the motor at intervals, for example, once ever hour.

Here is an example of a 2 RPM motor.

https://www.amazon.com/Greartisan-E...way&sprefix=10rpm+,aps,178&sr=8-2-spons&psc=1

 

You could use a stepper motor which can rotate as slow as you want. The step pulses could be provided by a logic circuit or a simple microcontroller - Arduino or PIC.

 

And if I used one of these motors? This model is widely used in industrial incubators, but I haven't managed to find out how to wire them.

 

They appear to be 120/230vac PM synchronous, if so they are most likely an AC stepper type motor ran off of AC supply.
It is virtually the same switching as a PSC motor, where the windings do double duty as run/start.
Max.

 

Is it safe you use a 5A Spdt with this 220v motor? I have decided to buy it, I see that many industrial incubators use this motor, but I haven't managed to fing any wiring schematics for it. It shouldn't be a problem as it used 3 cables, so it reverses easily, and I am thinking in using 2 limit switches so the motor stops when it reaches the limit.

 

See post #2 https://forum.allaboutcircuits.com/threads/type-of-120-v-ac-single-phase-motor.150396/#post-1287138
Max.

 

See post #2 https://forum.allaboutcircuits.com/threads/type-of-120-v-ac-single-phase-motor.150396/#post-1287138
Max.

Thanks for the diagram! But I'm still not sure if it safe to use a 5A SPDT that is often used in cars (12v).
Luís

 

Check the markings on the switch to see what the contact voltage rating is. They must be rated for mains voltage if that is what they will be switching.