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What kind of Motor is this and can it be used in some if any small hobbyist projects?

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Nerkec

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Sorry if this is not in the right subforum I'm new here.

Okay so I found this baby today in a box and after googling for a bit I came to a conclusion that this is in fact a motor. It sparked my interest and now I want to do some simple electronic projects.

What motor is this though, it is what I failed to understand? AC? DC? Something else? Can it be used in some projects? Thanks a lot!
 
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Mickster

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Looks like parts possibly from a floppy drive?
Both parts are motors and can be used in projects - the left one may be a 3-phase, or "Brushless" motor, and the right one may be a bi-polar stepper motor.
An internet search for those terms will help you to identify the type, as you have the items in front of you, and can confirm the number of connections each motor has. Once the correct type is identified, suitable drive circuits can be sourced or built.
 

Nerkec

New Member
Looks like parts possibly from a floppy drive?
Both parts are motors and can be used in projects - the left one may be a 3-phase, or "Brushless" motor, and the right one may be a bi-polar stepper motor.
An internet search for those terms will help you to identify the type, as you have the items in front of you, and can confirm the number of connections each motor has. Once the correct type is identified, suitable drive circuits can be sourced or built.
Hey thanks a lot! Yes they're from opened floppy drive I found. Time to dive in some tutorials! Thanks once again. Cheers
 

Pommie

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The large one looks like a miniature version of an LG direct drive washing machine motor. It might be worth googling as some people have designed drive systems for them.

Mike.
 

MaxHeadRoom78

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Yes, it is commonly known as an 'Outrunner' similar to now used in RC brushless motors.
It basically a 3ph motor/generator.
Max.
 

shortbus=

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Looks like parts possibly from a floppy drive?
Both parts are motors and can be used in projects - the left one may be a 3-phase, or "Brushless" motor, and the right one may be a bi-polar stepper motor.
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It is a stepper but is a "linear stepper motor" The shaft is a thread and the thread moves in and out of the motor. The moving part is inside the motor and is a threaded "nut" that turns and that moves the exposed thread in and out of the motor housing.


Linear Actuators
The rotary motion of a stepper motor can be converted into linear motion by several mechanical means. These include rack & pinion, belt and pulleys and other mechanical linkages. All of these options require various external mechanical components. The most effective way to accomplish this conversion is within the motor itself. The linear actuator was first introduced in 1968. Some typical linear actuators shown below.


Figure 9: Typical linear actuators

"Conversion of rotary to linear motion inside a linear actuator is accomplished through a threaded nut and leadscrew. The inside of the rotor is threaded and the shaft is replaced by a lead screw. In order to generate linear motion the lead screw must be prevented from rotating. As the rotor turns the internal threads engage the lead screw resulting in linear motion. Changing the direction of rotation reverses the direction of linear motion. The basic construction of a linear actuator is illustrated in figure 10." Above and picture from - https://www.haydonkerkpittman.com/learningzone/technicaldocuments/stepper-motor-theory

 

Nigel Goodwin

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It is a stepper but is a "linear stepper motor" The shaft is a thread and the thread moves in and out of the motor. The moving part is inside the motor and is a threaded "nut" that turns and that moves the exposed thread in and out of the motor housing.
Sorry, but not on any of the floppy steppers I've seen, it's a normal rotary stepper and the screw thread drives a slide - there's no need for a linear motion inside the motor - and if it was, there wouldn't need to be the threads on the outside of the shaft.
 

MaxHeadRoom78

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As Mickster said, it appears to be the pair of motors from a drive, one is a 3ph BLDC and the other a stepper.
Max.
 

Mickster

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It is a stepper but is a "linear stepper motor" The shaft is a thread and the thread moves in and out of the motor. The moving part is inside the motor and is a threaded "nut" that turns and that moves the exposed thread in and out of the motor housing.
Those types were commonly found on GM TBI throttle bodies, where they drove a cone-shaped wedge into and out of an air bleed orifice, to control the engine idle speed. They were known as IAC stepper motors (Idle Air Control).
 

shortbus=

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Sorry, but not on any of the floppy steppers I've seen, it's a normal rotary stepper and the screw thread drives a slide - there's no need for a linear motion inside the motor - and if it was, there wouldn't need to be the threads on the outside of the shaft.
It is or was in the few I took apart. The end of the threaded shaft was connected directly to the read sensor arm and didn't turn. I don't remember what brand they were, so other brands may have been made different.

By putting the nut inside the motor, like in the picture, it should/would make things more stable for the arm movement, since there is a ball bearing on each end of the nut, and a longer thread part.
 

gophert

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Sorry, but not on any of the floppy steppers I've seen, it's a normal rotary stepper and the screw thread drives a slide - there's no need for a linear motion inside the motor - and if it was, there wouldn't need to be the threads on the outside of the shaft.
I don't know if disk drives used motors like this with linear motion but all of the cd and DVD players used them. Something had to move the read/write head for magnetic disk drives too. I vividly remember the sound of a stepper motor whining so, I assume it was a stepper motor and a screw as shown. If you've never seen one in a magnetic disk drive, how do you propose the read/write head was controlled?

Oh, look, from 2:01 of this 3.5" foppy tear down video...
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A photo of the OPs motor - it moves the read-write head...
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394632F7-823E-43E3-B940-C28107FAA95C.jpeg
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And look, from 2:27, the other motor that's the floppy spinning motor...
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94A93614-6F7F-47EE-8915-DCA9A8DC9624.jpeg
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shortbus= Nailed it.

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Mickster

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^ The worm on the shaft of the motor, in the penultimate pic, is the drive part for moving the head carriage.
That shaft does not move in and out of the motor.

EDIT:
Additionally, for identification purposes, if it's just a stepper motor, you can twist the shaft.
The linear stepper motors usually have a key which prevents the shaft rotating with the nut, as that would defeat the purpose of having a finely-controlled positioning device.
 
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gophert

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The worm on the shaft of the motor, in the penultimate pic, is the drive part for moving the head carriage.
That shaft does not move in and out of the motor.
Correct. True for the OPs motor and for the one in the video.
 

Nigel Goodwin

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Correct. True for the OPs motor and for the one in the video.
And for every single CD and DVD player, of which I've repaired hundreds - they work in the exact same way, a rotary motor (usually just a DC motor, not even a stepper) the shaft of which has a coarse screw thread on it (as in the pictures here), with the sled directly mounted on that thread and running along it.

The very first Sony CD Players were a LOT more complicated, and used linear motors for the sled.
 

shortbus=

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The linear stepper motors usually have a key which prevents the shaft rotating with the nut, as that would defeat the purpose of having a finely-controlled positioning device.
Some are keyed and some aren't. The ones out of the disc drives I took out had an internal thread in them. A screw went through the read arm and into the end of the motor shaft to keep it from turning. Without that screw you could turn the motor threaded rod in and out of the motor. The threaded shaft in the motor needs to be nonturning for it to work. There used to be a small robot arm kit that used these linear steppers to move the "bicep" and "forearm" of the arm itself.
 

Mickster

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A screw went through the read arm and into the end of the motor shaft to keep it from turning. Without that screw you could turn the motor threaded rod in and out of the motor.
That screw is the key then.
 

shortbus=

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If I remember right the one that uses a screw in the end is called a "non-captive". The kind with a key is a "captive". It's all explained on the main HaydonKerkPittman website. There's a lot of information there about steppers and the Pittman/Maxon type gear motors.
 
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