# 12 volt motor characteristics

#### mendoza

Joined Nov 8, 2021
19
I am looking for a DC motor to make an olive vibrator. I would like to make the system as simple as possible. The motor is going to be connected to a 12 volt car battery. I am not an expert in motors but as the battery has an intensity between 20 and 50 amps, according to the formula Intensity = power/voltage, I should look at motors between 240 and 600 watts of power?

Where can I find motors with these characteristics?

#### Yaakov

Joined Jan 27, 2019
5,488
Welcome to AAC.

I'm afraid you are going about this backwards. Designing for a battery rather than for the task at hand is a mistake. To specify the motor you have to have some idea how much power the motor needs to sufficiently shake the tree. You can do this empirically by testing different motors but that is probably impractical. If I was doing this, I would try to find successful examples and look at the motors used in them, then figure out what power supply is needed.

Good luck.

#### mendoza

Joined Nov 8, 2021
19
Thank you for your response Yaakov!

Most of these machines use 12 volt motors and a power of about 250 watts, so that's enough (I haven't found any more information of the motors). And they are connected to a car or farm tractor 12 volts battery. Where can I find good motors with these characteristics? What other things would I have to find out about the motors?

#### Yaakov

Joined Jan 27, 2019
5,488
Thank you for your response Yaakov!

Most of these machines use 12 volt motors and a power of about 250 watts, so that's enough (I haven't found any more information of the motors). And they are connected to a car or farm tractor 12 volts battery. Where can I find good motors with these characteristics? What other things would I have to find out about the motors?
You will need to know the expected rotational speed (RPM) because the mechanism will depend on that. You might need to know the duty cycle since cooling could be a problem for such a relatively high powered motor.

You might just be able to buy a replacement motor for an existing commercial device and use that.

#### Yaakov

Joined Jan 27, 2019
5,488
Are you building a handheld rake or a whole tree shaker?

#### mendoza

Joined Nov 8, 2021
19
A whole tree shaker

#### mendoza

Joined Nov 8, 2021
19
Expected rotational speed is usually around 1000-1200 rpm, and replacement parts are not easy to find.

#### Yaakov

Joined Jan 27, 2019
5,488
Do you have plans for the device you are building?

#### mendoza

Joined Nov 8, 2021
19
No, I'm looking for a geared motor with those characteristics and then I'm going to put some connecting rods to simulate the vibration. I want to do something similar to what is described in this video:

Attached photo

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#### Yaakov

Joined Jan 27, 2019
5,488
Have you considered the rope type shakers? They seem simpler to construct. As far as the motor goes, the little research I have done suggests that you need to try a reasonably large motor like this one and see if it is enough.

#### Yaakov

Joined Jan 27, 2019
5,488
No, I'm looking for a geared motor with those characteristics and then I'm going to put some connecting rods to simulate the vibration. I want to do something similar to what is described in this video:

Attached photo
That's a rake style branch shaker, not a whole tree shaker. I am confused now.

#### mendoza

Joined Nov 8, 2021
19
Sorry, I got confused, it's a rake style branch shaker. Unfortunately a whole tree shaker does not work very well for olives.

#### Yaakov

Joined Jan 27, 2019
5,488
Sorry, I got confused, it's a rake style branch shaker.
I think if I was building this, I would try to adapt a cordless power tool motor. They can be very powerful and they are readily available.