Hard Driver motor

[Papabravo]

In RC control the thing is position of the control surfaces. As far as velocity is concerned the precise value is not that important but there has to be enough torque to get to the position required fast enough to be effective.

Think spin recovery with a wimpy rudder control and your baby becomes a crumpled pile of junk.

 

[ericgibbs]

hi atom,
So that I clear this for my own interest, I dismantled an old hard drive and removed the 4 wire motor.

Resistance values as per your findings, approx 2hm:

Determined which wire was which in the firing order.
Used a dual beam scope, kept one channel as reference and spun the motor by hand,
observed the other windings on the second scope channel in order to find the phasing.

Applied 5V in the firing sequence, the motor turns in 30deg 'steps', BUT there is very little torque.
Attempting to drive anything from the motor shaft would be pointless

This is exactly what papabravo has been saying thru this post.

However, looking at the output from the windings in would make an interesting project for a wind speed indicator.
[ I expect thats been done already!]

Hope this helps.

 

[Leftyretro]

In RC control the thing is position of the control surfaces. As far as velocity is concerned the precise value is not that important but there has to be enough torque to get to the position required fast enough to be effective.

Think spin recovery with a wimpy rudder control and your baby becomes a crumpled pile of junk.

I think you are describing the smaller motors used in R/C servos. I was referring to the much larger Brushless DC motors used to power the plane via a propeller.

**broken link removed**

Lefty

 

[AtomSoft]

hi atom,
So that I clear this for my own interest, I dismantled an old hard drive and removed the 4 wire motor.

Resistance values as per your findings, approx 2hm:

Determined which wire was which in the firing order.
Used a dual beam scope, kept one channel as reference and spun the motor by hand,
observed the other windings on the second scope channel in order to find the phasing.

Applied 5V in the firing sequence, the motor turns in 30deg 'steps', BUT there is very little torque.
Attempting to drive anything from the motor shaft would be pointless

This is exactly what papabravo has been saying thru this post.

However, looking at the output from the windings in would make an interesting project for a wind speed indicator.
[ I expect thats been done already!]

Hope this helps.

Thanks ill take it as a waste of time lol I have other normal motors ill use then for certain projects.

Can i control a motor like this?
By control i mean be able to move it in small increments and with a h bridge be able to reverse in small increments?

 

[ericgibbs]

Thanks ill take it as a waste of time lol I have other normal motors ill use then for certain projects.

Can i control a motor like this?
By control i mean be able to move it in small increments and with a h bridge be able to reverse in small increments?

Hi,
That motor is for robotics, so it should OK for PIC controlling.

Its a pity you dont live in the UK, I have lots of motors, steppers and brushless, which I will never use.!

There is a stepper motor in the Oshonsoft modules.

 

[AtomSoft]

I was thinking about making a h-bridge with 4 transistors like this sort of:
**broken link removed**

 

[AtomSoft]

Hi,
That motor is for robotics, so it should OK for PIC controlling.

Its a pity you dont live in the UK, I have lots of motors, steppers and brushless, which I will never use.!

There is a stepper motor in the Oshonsoft modules.

Thanks i wish i lived there too what do you think about the above image. I made in photoshop its a rough draft. You think would work?

 

[ericgibbs]

hi,
Looking at the diagram, assume that the left hand pair of gates are HIGH and the right side pair are LOW, what is the current path.?

Likewise when the HIGH's , LOWs are reversed.?

 

[AtomSoft]

Since this is theory...

Lets say left side is A and the Right side is B

When the pic sends a HIGH to A and a LOW to B the motor should spin forward

When the pic sends a LOW to A and a HIGH to B the motor should reverse

All other commands should stop the motor. Remember this is theory

 

[AtomSoft]

Sort of like multiplexed LEDs. Sort of is the keyword.

there is 1 NPN and 1 PNP on the left and right side
So when it goes high it closes 1 gate and opens the other and when low it flips the gates. The right side is flip upside down so it would be like

if LEFT.TOP = CLOSED then
Right.Bottom = CLOSED
Right.Top = Open
Left.Bottom = Open
end if

if LEFT.TOP = OPEN then
Right.Bottom = OPEN
Right.Top = CLOSED
Left.Bottom = CLOSED
end if

So its like :

Image:H bridge operating.svg - Wikipedia, the free encyclopedia

 

[Papabravo]

I think you are describing the smaller motors used in R/C servos. I was referring to the much larger Brushless DC motors used to power the plane via a propeller.

**broken link removed**

Lefty

You are correct, I had not considered that a possibility. So do the propellers have a fixed pitch or can you chnage the pitch as well?

 

[AtomSoft]

Just found a broken printer and took out the stepper from it. Not sure which pin is what tried the resistance thing but i get like:

_Pins_
1 & 2 = 3.0 Ohms
1 & 3 = 0
1 & 4 = 0
-----------
2 & 3 = 0
2 & 4 = 0
-----------
3 & 4 = 3.0 ohms


Now what?

 

[ericgibbs]

Just found a broken printer and took out the stepper from it. Not sure which pin is what tried the resistance thing but i get like:

_Pins_
1 & 2 = 3.0 Ohms
1 & 3 = 0
1 & 4 = 0
-----------
2 & 3 = 0
2 & 4 = 0
-----------
3 & 4 = 3.0 ohms


Now what?

Hi atom,
I dont think you mean 0hm:, is it really infinity.?

If you still have Oshonsoft sim set up, look at the stepper motor module.

Regards

Look here:
**broken link removed**

 

[bryan]

EM-2 Linker error: “could not find file ‘c018i.o’”
Enter the proper directory path in Project>Build Options…>Project General tab. Set
the Library Path box to “C:\mcc18\lib”. c018i.o is the start-up library for MPLAB
C18. It sets up the stack, initializes variables, then jumps to main() in the application.

For some reason i get this error.. the thing is that the file is
there im using ver 8 of MPLABError - could not find file 'c018i.o'.
Errors : 1[/code]

 

[AtomSoft]

There is nothing wrong with my path setup i checked multiple times. Everything is setup ok just still get same error.My work around was to set it under:
MENU | Projects -> Build Options -> Project... C18 tab

EM-2 Linker error: “could not find file ‘c018i.o’”
Enter the proper directory path in Project>Build Options…>Project General tab. Set
the Library Path box to “C:\mcc18\lib”. c018i.o is the start-up library for MPLAB
C18. It sets up the stack, initializes variables, then jumps to main() in the application.

 

[AtomSoft]

Yeah infinity i suppose i dont know how to make that sign tho lol ∞

Hi atom,
I dont think you mean 0hm:, is it really infinity.?

If you still have Oshonsoft sim set up, look at the stepper motor module.

Regards

Look here:
**broken link removed**

 

[AtomSoft]

ok i think i get it now but at what speed should i send a Pulse? or is it trial and error depending on what im trying to do with it?

 

[AtomSoft]

Using PORT a 4:1
ok im trying this code and no luck but i feel it trying:

#include <p18f1320.h>
#include <delays.h>
#pragma config OSC = INTIO1, WDT = OFF, LVP = OFF, DEBUG = ON



void main (void){
  TRISA = 0b00000000; //output
  
  while(1){
     PORTA = 0b00000010;
     Delay10TCYx(1);

     PORTA = 0b00000110;
     Delay10TCYx(1);

     PORTA = 0b00000100;
     Delay10TCYx(1);

     PORTA = 0b00001100;
     Delay10TCYx(1);

     PORTA = 0b00001000;
     Delay10TCYx(1);

     PORTA = 0b00011000;
     Delay10TCYx(1);

     PORTA = 0b00010000;
     Delay10TCYx(1);

     PORTA = 0b00010010;
     Delay10TCYx(1);

  }
}

 

[Sceadwian]

You could send a static 'start up' sequence to the motor to get it started spinning, then using a hall effect sensor or some other feedback to determine the motor spindle speed/phase you could dynamically adjust the speed of the motor until the desired RPM was reached. I'd like to see someone test one of these to destruction, because if you can drive the pulses fast enough and synchronize them the only limit to the speed of the motor is mechanical failure or the torque being insufficient to increase speed at some point.

 

[AtomSoft]

How woul di go about sending this startup sequence? speed isnt a factor yet if i cant get it to spin at all lol

You could send a static 'start up' sequence to the motor to get it started spinning, then using a hall effect sensor or some other feedback to determine the motor spindle speed/phase you could dynamically adjust the speed of the motor until the desired RPM was reached. I'd like to see someone test one of these to destruction, because if you can drive the pulses fast enough and synchronize them the only limit to the speed of the motor is mechanical failure or the torque being insufficient to increase speed at some point.