Stepper motor doesn't have a brand or model number!

[eagle1109]

Hello,

I only have a stepper motor which doesn't have a brand name or model number.

I tried to drive it by a normal stepper motor code, but I can't drive it like my 28BYJ which runs smoothly.

These are the pictures, if anyone can tell me its name or how to drive it with an Arduino or a PIC chip.

It's the one on the left:

moderator action: removed links to external file servers.

 

[d123]

Hi,

Stupid question, maybe: Have you measured the coil resistances to check which wires belong to which coil? ...Or messed around with other sequences than the one tried so far to see what happens and go eliminating those sequences that do not work?

 

[srizbf]

how many wires are there in the motor?
6 or 5? from that decide uni or bipolar.identify the common wire. then drive with the proper sequence.

 

[d123]

Hi,

It has four wires, so I'd guess that it's a bipolar stepper with two coils.

 

[eagle1109]

Hi,

Stupid question, maybe: Have you measured the coil resistances to check which wires belong to which coil? ...Or messed around with other sequences than the one tried so far to see what happens and go eliminating those sequences that do not work?

That's the 1st thing I did, I then encountered a strange behavior, as the stepper motor work not in consistent pattern as the 28BYJ.

I think it's not a good/reliable stepper motor for these reasons:
1. It doesn't have any info on it, which means it's not a brand or something.
2. The shaft isn't stiff as what a stepper motor should be, I can move it when the motor isn't connected. And also when it's connected to power.
3. I uploaded the 28BYJ Arduino code and connected this unknown stepper motor. And it runs uncontrollably, I can play with the direction of the shaft, as it moves to forward, I can move it backward just by touching it !! Piece of garbage .. really!

how many wires are there in the motor?
6 or 5? from that decide uni or bipolar.identify the common wire. then drive with the proper sequence.

It's really unreliable stepper motor .. that's my latest conclusion yesterday after couple of tests. Not worth putting it in a project! The 28BYJ is much more better one.

 

[KlausST]

Hi,

2. The shaft isn't stiff as what a stepper motor should be, I can move it when the motor isn't connected.

The torque depends on current.
No current, low torque, just caused by the magnetic remanence.

Klaus

 

[eagle1109]

I was doing this last night.



Connecting a PIC to L293D chip which drives this stepper motor. The problem is that after some time the setup was connected as follows:
1. Connecting the PIC to 5V adapter and also supplying the L293D with the same voltage.
2. According to this diagram, I learned that I have to connect the external voltage for the stepper motor power to pin 8 of the L293D.



The problem after some time the stepper motor got really HOT, I couldn't touch it. Why is that?

 

[KlausST]

Hi,

The problem after some time the stepper motor got really HOT, I couldn't touch it. Why is that?

If I understand correctly, then you don't have any specification of the motor.
--> What makes you think that it is rated for 12V?

If the motor is getting too hot, then obviously the motor current is too high --> usually caused by too high voltage.

Klaus

 

[srizbf]

L293 can drive a bipolar two phase stepper motor.
pin 8 is for motor supply. and pin16 for logic supply.

if the motor gets heated implies that you have not given proper logic input sequence.

 

[eagle1109]

Hi,


If I understand correctly, then you don't have any specification of the motor.
--> What makes you think that it is rated for 12V?

If the motor is getting too hot, then obviously the motor current is too high --> usually caused by too high voltage.

Klaus

The stepper motor in the picture is PM35L-048-HPH7 it's another one than the one I posted in the 1st post, it's rated as 24V, 600mA and I was connecting it yesterday at 6V just to run smoothly.

moderator action: removed link to external server

I have to mention than according to this pin diagram and the diagram of the L293D I have to connect the stepper voltage to pin 8, so what I did. I connected an external voltage source with a separate voltage than the one running the PIC and L293D, at 6V on pin 8 and connected the middle rail of this stepper motor to the same 6V, could this the cause of the excessive heat?

L293 can drive a bipolar two phase stepper motor.
pin 8 is for motor supply. and pin16 for logic supply.

if the motor gets heated implies that you have not given proper logic input sequence.

As I described above I connected the middle pin of the stepper motor and the external 6V to pin 8 of L293D. Could that be a problem in wiring?

 

[srizbf]

...
As I described above I connected the middle pin of the stepper motor and the external 6V to pin 8 of L293D. Could that be a problem in wiring?

If you mean 'middle pin' as the common wire in the motor , then L293 is not suitable. and pin 8 is 5v logic here.

Just post your test circuit diagram. (Even neatly hand drawn is enough).

 

[eagle1109]

This is the diagram.

 

[srizbf]

connect four diodes in reverse bias mode across the four windings A1and A2 and B1 and B2.
pins 4,5 and 13 and 12 are the ground return for motor current.
They should be attached with higher area conductors . a possible cause for heat.

The sequencs you apply to in1,2,3 and 4 are to be according to the stepping sequences.
if in1 and in2 are both 0 (same to in3 and in4) then also the Ic draws more current and produce execessive heat.

 

[KlausST]

Hi,

connect four diodes in reverse bias mode across the four windings A1and A2 and B1 and B2.
pins 4,5 and 13 and 12 are the ground return for motor current.

I can´t see how you want to connect it nor how it can work. Can you draw a schematic?

Klaus

 

[eagle1109]

Well, I think it's a normal phenomena in running stepper motors, this is new to me because I don't have much experience with motors.

I found this video on YouTube which explains why it gets HOT.

 

[srizbf]

Hi,



I can´t see how you want to connect it nor how it can work. Can you draw a schematic?

Klaus

The diagram is the same as in the previous ecept the freewheeling diodes across windings.
A '1' switch OFF the winding and a '0' energise the winding.
(Normal stepper sequence is usually shown with '1' as energised).

 

[KlausST]

Hi,

The diagram is the same as in the previous

There are many diagrams. Not shure what you mean...

freewheeling diodes across windings.

--> freewheeling diodes usually don't work on stepper motor windings.
If you think you have a working solution I strongly recommend to show your circuit.

A '1' switch OFF the winding and a '0' energise the winding.

Again a useless information without additional information...
"1" and "0" usually are for logic signals. But a stepper has no logic input signals. Are you talking about the driver IC inputs?

Again I ask for clear, unambigous informations.

Klaus

 

[srizbf]

i can see only one circuit diagram in the posts.
thats the diagram i refer to.
others are only photos.

freewheeling diodes doesnt work ?


the 1 and 0 are liogic inputs only.
thats all the useful info.

 

[KlausST]

Hi,

I can´t see that you are willing to provide useful informations.

i can see only one circuit diagram in the posts.
thats the diagram i refer to.
others are only photos.

freewheeling diodes doesnt work ?

* post#7 shows a circuit diagram with a unipolar stepper motor --> free wheeling diodes don´t work
* post#12 shows a circuit diagram with a unipolar stepper motor --> free wheeling diodes don´t work

the 1 and 0 are liogic inputs only.
thats all the useful info.

A stepper motor has no logic inputs.

Klaus

 

[eagle1109]

Do you think that there's a solution for the excessive heat of the stepper motor? Or it's a normal operating condition?