Which DC motors are inside SG90 servos

Thread Starter

salvus

Joined Apr 2, 2020
49
I need some small and cheap dc motors (smaller than the typical 130 motors that you see). The ones inside the SG90 servos are perfect for my appocation. I have taken a few out of SG90 servos but I am struggling to find any small dc motors like this that I can just buy to use straight away. Do you know what they are called / a model number I can look up?

Many thanks
 

Reloadron

Joined Jan 15, 2015
6,581
Based on your post alone you may want to try a Google of "cell phone vibrator motor" Less sny specifications like voltage and dimensions other than "small" that's where I would start. Here is but on example of the dozens of cheap 3.0 volt motors out there.

Ron
 

Thread Starter

salvus

Joined Apr 2, 2020
49
I think the small motors inside the sg90 servos are all very similar if not the same. The specifications would be very similar to those motors.

Do you know if it‘s possible to just get the motor without the vibration bit attached to the shaft?
 

Reloadron

Joined Jan 15, 2015
6,581
Do you know if it‘s possible to just get the motor without the vibration bit attached to the shaft?
I doubt it but if you got a few you may be able to remove the weight. The problem with a DG90 servo motor is it's a servo motor:

  • Torque: 2.0kg/cm(4.8V), 2.2kg/cm(6V)
  • Speed: 0.09s/60°(4.8V), 0.08s/60°(6V)
  • Rotate angle: 180°
  • Operating voltage: 4.8 ~ 6V.
  • Gear: plastic.
  • Dead band: 7us.
  • Weight: 10.5g.
Servo motors are not designed to be a motor having continuous 360 degree rotation. I know on some the internal feedback can be eliminated so they can be converted into a motor but I am not sure on the SG90 versions. The control line is pulsed with a PRT of 20 mSec for center. Position "0" (1.5 ms pulse) is middle, "90" (~2ms pulse) is middle, is all the way to the right, "-90" (~1ms pulse) is all the way to the left. A Google of "micro motors" and "miniature motors" brings up some inexpensive small motors.

Ron
 

Thread Starter

salvus

Joined Apr 2, 2020
49
its just the small DC motor inside the servo that I want. This isnt restricted to 180 degress, that is just because of the potentiomenter and a little plasitc stopper and the electronics. I dont need any of that, just the motor.

I have seen the N20 motors but they seem to mostly conme with a gear box, but I dont want that. Do you know where I get get just the motors?

Many thanks
 

Thread Starter

salvus

Joined Apr 2, 2020
49
i think those are the 130 hobby motors, they are quite a bit bigger. I basically want physically smaller versions of those.
 

MisterBill2

Joined Jan 23, 2018
11,874
So the want is for a "Small DC motor" with some unspecified torque output at some unspecified speed , at some unspecified supply voltage. The actual diameter and length of the shaft are unspecified, as well as the acceptable cost and the quantity .needed. There are quite a few manufacturers of small motors around, and they produce very good products. Many of them have websites that describe the products available from stock. Falhauber is one company that comes to mind.

But I hope that the TS realizes that referencing a motor from some RC servo device is not close to an adequate description.
Another option may be to try an actual hobby store, such as "Hobby Lobby", which does sell RC components. Even if they do not carry the exact product, they may be able to provide information.
 

MisterBill2

Joined Jan 23, 2018
11,874
NO! The description of "like", or "similar to" is meaningless unless the person is familiar with that product. Hobby-class RC-servo devices are one of the few things I have not worked with. So how would you expect a motor supplier to be familiar with a product that they have never seen???
Keep it in mind that the majority of technical people have never opened an RC servo device, or even used one. And a supplier is used to providing products that match a particular set of specifications.
If you are not willing or able to describe the product you seek it is not likely that others will be able to help.
 

Ya’akov

Joined Jan 27, 2019
5,642
NO! The description of "like", or "similar to" is meaningless unless the person is familiar with that product. Hobby-class RC-servo devices are one of the few things I have not worked with. So how would you expect a motor supplier to be familiar with a product that they have never seen???
Keep it in mind that the majority of technical people have never opened an RC servo device, or even used one. And a supplier is used to providing products that match a particular set of specifications.
If you are not willing or able to describe the product you seek it is not likely that others will be able to help.
Since you don’t know bout hobby servos you wouldn’t know that “SG90” is not a model number, it’s a generic identifier for a certain hobby servo size and capacity. Many manufacturers make SG90 equivalent servos.

Since SG90 servos all have to be the same size, voltage, current, and do the same amount of work—within a pretty small window—the motors in them will be very similar if not identical.

I think it was originally a particular part number from a manufacturer, but I can’t easily find the origin.
 

MisterBill2

Joined Jan 23, 2018
11,874
Please consider that the vast majority of technical people are not familiar at all with hobby RC servos, and most motor supply people even less familiar with them.
If any degree of accuracy is required in response to a request, that request needs to be more detailed. Otherwise the answer is always "seven."
 

Thread Starter

salvus

Joined Apr 2, 2020
49
All the motors in them are the same or very close, so the answer is not seven, as the information given is specific. The question assumes that you are familar with these motors. If not, then you wouldn't be able to answer the question.
 
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