Servo from Dc motor?

Traditional mobile robotics is all about wheeled robots.
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Post by MOHIT JINDAL » Wed Jul 04, 2012 3:34 pm

Post by MOHIT JINDAL
Wed Jul 04, 2012 3:34 pm

Hi,
Can you tell me how to make servo motor from dc motor ? I think one encoder and potentiometer is required. Help! as servo motors are costly. :roll:
Hi,
Can you tell me how to make servo motor from dc motor ? I think one encoder and potentiometer is required. Help! as servo motors are costly. :roll:
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Post by MarcoP » Wed Jul 04, 2012 3:57 pm

Post by MarcoP
Wed Jul 04, 2012 3:57 pm

Hi

Hope you don't mind but i have created a new thread for this.

To answer your question, you could do with only with a potentiometer.
However a normal dc motor would not be a good option.

Servos use small dc motors with low torque and a set of gears to reduce speed and increase torque. Without that speed reduction it is very hard to do position control.

It all depends on the motors you want to use and the application.

The cheapest servos we have are here...

Regards
Hi

Hope you don't mind but i have created a new thread for this.

To answer your question, you could do with only with a potentiometer.
However a normal dc motor would not be a good option.

Servos use small dc motors with low torque and a set of gears to reduce speed and increase torque. Without that speed reduction it is very hard to do position control.

It all depends on the motors you want to use and the application.

The cheapest servos we have are here...

Regards
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Post by wiweet » Wed Jul 04, 2012 4:15 pm

Post by wiweet
Wed Jul 04, 2012 4:15 pm

As another option you could try to explore possibility offered from Openservo.


OpenServo is an open community-based project started by Mike Thompson with the goal of creating a low-cost digital servo for robotics. Currently maintained by Barry Carter, the OpenServo project continues to flourish with new code, new hardware, and rich documentation set.[url]http:www.openservo.com[/url]
As another option you could try to explore possibility offered from Openservo.


OpenServo is an open community-based project started by Mike Thompson with the goal of creating a low-cost digital servo for robotics. Currently maintained by Barry Carter, the OpenServo project continues to flourish with new code, new hardware, and rich documentation set.[url]http:www.openservo.com[/url]
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Post by MOHIT JINDAL » Wed Jul 04, 2012 4:24 pm

Post by MOHIT JINDAL
Wed Jul 04, 2012 4:24 pm

Thanks to both. I want to use 60rpm metal gear 38kgcm torque DC motor to make servo. If i use the circuit board of low cost servo and solder high torque dc motor. Will it work ? :wink:
Thanks to both. I want to use 60rpm metal gear 38kgcm torque DC motor to make servo. If i use the circuit board of low cost servo and solder high torque dc motor. Will it work ? :wink:
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Post by wiweet » Wed Jul 04, 2012 4:46 pm

Post by wiweet
Wed Jul 04, 2012 4:46 pm

If your new high torque dc motor does not exceed the maximum current limitation of the h-bridge(driver) from your low cost servo board, it may works...(with unpredictable response and accuracy, perhaps) on the contrary if your new high torque dc motor exceed that current limitation, you will eventually burn/toast your low cost servo board.
If your new high torque dc motor does not exceed the maximum current limitation of the h-bridge(driver) from your low cost servo board, it may works...(with unpredictable response and accuracy, perhaps) on the contrary if your new high torque dc motor exceed that current limitation, you will eventually burn/toast your low cost servo board.
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Post by MOHIT JINDAL » Thu Jul 05, 2012 3:23 am

Post by MOHIT JINDAL
Thu Jul 05, 2012 3:23 am

Here is the DC motor Specification:- :arrow:

60RPM 12V DC motors with Metal Gearbox and Metal Gears
18000 RPM base motor
6mm Dia shaft with M3 thread hole
Gearbox diameter 37 mm.
Motor Diameter 28.5 mm
Length 63 mm without shaft
Shaft length 15mm
180gm weight
38kgcm torque
No-load current = 800 mA, Load current = upto 7.5 A(Max)

I hope someone can help in making Servo Motor from it :roll:

Here is the Servo Motor Specification :arrow: I want to use its Board and potentiometer:-

Required Pulse: 3-5 Volt Peak to Peak Square Wave
Operating Voltage: 4.8-6.0 Volts
Operating Temperature Range: -10 to +60 Degree C
Operating Speed (4.8V): 0.18sec/60 degrees at no load
Operating Speed (6.0V): 0.14sec/60 degrees at no load
Stall Torque (4.8V): 14kg/cm
Stall Torque (6.0V): 16kg/cm
360 Modifiable: Yes
Potentiometer Drive: Indirect Drive
Here is the DC motor Specification:- :arrow:

60RPM 12V DC motors with Metal Gearbox and Metal Gears
18000 RPM base motor
6mm Dia shaft with M3 thread hole
Gearbox diameter 37 mm.
Motor Diameter 28.5 mm
Length 63 mm without shaft
Shaft length 15mm
180gm weight
38kgcm torque
No-load current = 800 mA, Load current = upto 7.5 A(Max)

I hope someone can help in making Servo Motor from it :roll:

Here is the Servo Motor Specification :arrow: I want to use its Board and potentiometer:-

Required Pulse: 3-5 Volt Peak to Peak Square Wave
Operating Voltage: 4.8-6.0 Volts
Operating Temperature Range: -10 to +60 Degree C
Operating Speed (4.8V): 0.18sec/60 degrees at no load
Operating Speed (6.0V): 0.14sec/60 degrees at no load
Stall Torque (4.8V): 14kg/cm
Stall Torque (6.0V): 16kg/cm
360 Modifiable: Yes
Potentiometer Drive: Indirect Drive
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Post by MOHIT JINDAL » Fri Jul 13, 2012 2:55 am

Post by MOHIT JINDAL
Fri Jul 13, 2012 2:55 am

If i use dynamixel Ax12+ circuit board and replace the 12volt motor with another 12v motor with 5amp current. Will it burn out ? :x Ax12+ takes 1.2amp current. So i think it will run the 5amp motor also :roll:
If i use dynamixel Ax12+ circuit board and replace the 12volt motor with another 12v motor with 5amp current. Will it burn out ? :x Ax12+ takes 1.2amp current. So i think it will run the 5amp motor also :roll:
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