[SOLVED] I need help with my servomotor

[dxtr]

Hey everyone
i'm new to the electronics world and also to english languages
i recently bought a Servomotor and i'm hopping to use it as motor , i read that it have 3 wires red (+5v) , black (gnd) and command wire
well , i created a small program using pic 16f84 allow me to generate pwm signal (Period = 20ms , pulse = 1ms) , but all i have is a 90° Rotation :shock: and it stops
Whats the problem and how can i use it as motor
thank u in advance

 

[tpetar]

If I understand correctly you whant to use servo motor just as motor ?

 

[goldsmith]

Dear dxtr
Hi
Try to change duty cycle of your PWM , from zero up to 80 percent
Best Wishes
Goldsmith

 

[dxtr]

@tpetar : Yes i want to use as Motor
@goldsmith : Thank u , i will try it and tell u the result

 

[bigdogguru]

i recently bought a Servomotor and i'm hopping to use it as motor , i read that it have 3 wires red (+5v) , black (gnd) and command wire
well , i created a small program using pic 16f84 allow me to generate pwm signal (Period = 20ms , pulse = 1ms) , but all i have is a 90° Rotation :shock: and it stops

Whats the problem and how can i use it as motor

The simple answer is you cannot, at least not without taking it a part and modifying it.

Most RC style servos have a limited rotation ranging from 90° to 360° depending on the exact make and model.

They are designed to provide a controllable limited rotation determined by pulse width. Most devices require a pulse width or duty cycle ranging from 1ms to 2ms with a total cycle time of 20ms.

As you increase the pulse width or duty cycle the servo will rotate through its set rotation range. The pulse must be constantly repeat to hold the servo at the desired position.

You have not elaborated on the actual requirement of the motor, however it sounds like you may need a simple DC or BLDC motor to fulfill your requirements.

BigDog

 

[dxtr]

The same problem
by the way its just simulation in isis , it possible to be just a false interpretation of isis ?
else i can post my .asm to see if i'm mistaken in the code (i'm sure im not )

---------- Post added at 22:53 ---------- Previous post was at 22:51 ----------

@bigdogguru : Thank you for making this claire to me , i think i should just a DC motor

 

[bigdogguru]

It is possible, however it appears the simulation is correct.

Have you attempted to increase the duty cycle from 1ms to 2ms will retain the total cycle time of 20ms?

This should rotate the servo to its full rotational position.

BigDog

 

[goldsmith]

Can you tell us that what do you want to do , exactly ? perhaps we can help you with better choices . do you want to use it for a robot ?
Wish you the best
Goldsmith

 

[bigdogguru]

@bigdogguru : Thank you for making this claire to me , i think i should just a DC motor

I'm glad I could help.

For simply application a DC motor should suffice.

BigDog

 

[dxtr]

@goldsmith : Yes i want to use it for my small project , its an Rc car, its my first project
by the way i've just find how to turn the servo into a motor
what do u suggest , buy new motor or turn my servo into a motor ?

 

[bigdogguru]

I would suggest buying a new motor or finding a used one in an appliance.

The servo may come in handy in the future, so why modify it.

BigDog

 

[goldsmith]

If you wanna use some batteries as supply voltage , i don't suggest you a simple DC motor , there are many better ways .
And my reason , about preventing from DC motors : the torque of each DC motor is very very high , and it means that if you try to stop it with your hand , it will try to increase it's current to challenge with your force . and if can't , it will burn simply .
And if you has some batteries as your supply , thus , when the way isn't direct and you have some snags , it will vocate your batteries.
Best Wishes
Goldsmith

 

[dxtr]

Thank you so much for your help guys

---------- Post added at 23:54 ---------- Previous post was at 23:14 ----------

Hey again
the servo i have is HSR-1425CR and i read in this article that its already modified to work as motor
**broken link removed**
am i lucky or i have to buy Motors ?
and what does this means :
Control System: +Pulse Width Control 1500usec Neutral
Required Pulse: 4.8-6.0 Volt Peak to Peak Square Wave
i mean whats the value if the period and the pulse

 

[bigdogguru]

the servo i have is HSR-1425CR and i read in this article that its already modified to work as motor
**broken link removed**
am i lucky or i have to buy Motors ?

If it is a Continuous Rotation (CR) Servo, then you are lucky!

and what does this means :
Control System: +Pulse Width Control 1500usec Neutral
Required Pulse: 4.8-6.0 Volt Peak to Peak Square Wave
i mean whats the value if the period and the pulse

I have actually never used a CR Servo.

However, I believe it means the servo is held stationary with a duty cycle of 1.5ms and total cycle of 20ms.

If the duty cycle (pulse width) is less than 1.5ms the servo rotates counter clockwise, if it is greater than 1.5ms it rotates clockwise and the farther the duty cycle (pulse width) from neutral the faster the rotation.

Did you notice the servo with the tire attached?





BigDog

 

[dxtr]

If it is a Continuous Rotation (CR) Servo, then you are lucky!



I have actually never used a CR Servo.

However, I believe it means the servo is held stationary with a duty cycle of 1.5ms and total cycle of 20ms.

If the duty cycle (pulse width) is less than 1.5ms the servo rotates counter clockwise, if it is greater than 1.5ms it rotates clockwise and the farther the duty cycle (pulse width) from neutral the faster the rotation.

Did you notice the servo with the tire attached?

View attachment 74147



BigDog

Yes i noticed , i think i will just use this servo since its could work as Motor.

 

[bigdogguru]

Good Luck

Report back your progress.

BigDog

 

[dxtr]

Yes i will
thank you again