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Topic: BEGINNERS: WHICH TYPE OF MOTOR .? (Read 6923 times) previous topic - next topic

lastchancename

Mar 03, 2020, 07:56 pm Last Edit: Jun 06, 2020, 03:14 am by lastchancename
A simple 'brushed' DC MOTOR is the cheapest starting point...  a hobby motor.
You'd use an FET (forward only) or h-bridge (bi-directional) to DRIVE that motor with your code.

If knowing the shaft position is important, then some form of mechanical coupling to the motor shaft / load is needed.
You'll also need some reduction gearing or coupling like that used inside an RC servo - to get the low speed and torque needed.  A stand-alone motor's position is arbitrary, and will need some feedback to your program, so you know where it is.

A servo MOTOR is fine (basically the same as a DC motor) with internal feedback & gearing, but as noted elsewhere, most RC SERVOs are limited in their rotation to around 180 degrees.  They're convenient becaipuse they are ABSOLUTE positioners... you just tell it to go to X, and if it can, it will.

STEPPER motors are also useful - but a different approach, which you control via driver from your code.  Steppers are also positioned RELATIVE to a known point... often a limit switch, or encoder feedback.

EDIT: Added the specific 'brushed' DC adjective!

Here's a useful explanation https://youtu.be/LXURLvga8bQ
Experienced responders have a nose for laziness, (they were beginners once)... Sure, there are trolls, chest-beaters, and pretenders - but the help you'll get here is about as good as it gets - if you try to help youself!.

slipstick

A simple DC MOTOR is the cheapest starting point...
You'd use an FET (forward only) or h-bridge (bi-directional) to DRIVE that motor with your code.
That's a simple BRUSHED DC motor.

Then there are Brushless DC motors (sometimes called BLDC), which have 3 wires rather than the 2 of a brushed motor and which need an ESC (Electronic Speed Controller) to drive them. They can then be driven in approximately the same way as a servo.

Steve

lastchancename

Fair point.  For beginners it's likely out of their skil level, but worth mentioning.
Experienced responders have a nose for laziness, (they were beginners once)... Sure, there are trolls, chest-beaters, and pretenders - but the help you'll get here is about as good as it gets - if you try to help youself!.

maxzax

AC Brushless Motors. AC brushless motors are some of the most popular in motion control. ...
DC Brushed Motors. In a DC brushed motor, brush orientation on the stator determines current flow. ...
DC Brushless Motors. ...
Direct Drive. ...
Linear Motors. ...
Servo Motors. ...
Stepper Motors.

lastchancename

#4
Mar 04, 2020, 03:59 am Last Edit: Mar 04, 2020, 03:59 am by lastchancename
You were paying attention in class !

I doubt anyone coming here for beginner tutorials will be looking for AC brushless motors,  but linear motors and direct-drive are a twist on the simple motors... they also need a little more understanding than most ten post beginners.

But it's certainly good to include them for completeness.
Experienced responders have a nose for laziness, (they were beginners once)... Sure, there are trolls, chest-beaters, and pretenders - but the help you'll get here is about as good as it gets - if you try to help youself!.

sugandhan

Whenever speed is concerned with continuous rotation we need to go with dc motor. But if you like to monitor the rotation of the motor accurately you need to use stepper motor. If you need accurate angles between one single rotation you can go for servo motor.

jackthomson42

If you are new then you shouldn't try brushless DC Motor, I have used it in quadcopter and was quite difficult to control. You should start with simple DC Motors or servo motors. I would recommend you to try servo motor in the start as you don't need any driver to control them.
If you want to fly, you need to try .....

lastchancename

#7
May 01, 2020, 02:47 pm Last Edit: May 01, 2020, 02:49 pm by lastchancename
Just to point out that a 'servo motor' in the hobbyist context, usually IS a DC motor driven by a 'feedback control loop'.

An RC 'servo' is that same motor with a feedback controller wrapped around it - in a convenient single unit.

The OP explains most of this.
Experienced responders have a nose for laziness, (they were beginners once)... Sure, there are trolls, chest-beaters, and pretenders - but the help you'll get here is about as good as it gets - if you try to help youself!.

carmal

If you are new then you shouldn't try brushless DC Motor, I have used it in quadcopter and was quite difficult to control. You should start with simple DC Motors or servo motors. I would recommend you to try servo motor in the start as you don't need any driver to control them.
Had the same problem with brushless DC Motor, don't repeat this mistake

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