DIY DC Servo from Ordinary Motor

www.bored-engineer.com, I was playing with DC motors and PID loops to make a DC servo capable of running a small CNC router. A low current 6 volt motor was used in this prototype and is run with basically no load.

Category:

Entertainment

Tags:

• cnc
• dc
• servo
• diy
• microcontroller

[reactive]

I can't believe people are actually arguing over this... what half of you are describing is a RC servo for use in planes, cars etc. This was built as a test for a DC servo in a CNC machine that tracks speed and position. The patterned disc forms a quadrature encoder that is picked up by the two optical sensors. They feed into a 16-bit PIC running a PID loop, the PIC outputs PWM to a H-bridge which drives the motor. The project never got further than this, it was more of a leaning exercise

[practicing]

It's quite obvious to me that the gears serve to step-up the rotation of the encoder in order to get more pulses per revolution. Which is actually a brilliant idea on how to achieve high positional resolution from a low resolution encoder. Also, I see some electronics which I assume is the PID tuning circuitry. That IS as servo motor. I say, excellent job.

[jinxym]

i think he has made a table feed for a project cnc router out of a dc servo , what ever it is nice job , ignore the twats that post their ignorant dribble lol regards fellow engineer jinxy

[xasdrubalex]

@dany21359 servo -> servo control --- from latin/to english in a really bad way --> enslavement control (and that's what you have when you add to a motor a feedback loop)

you have a servo when you're able to push it to do what you want, position, speed, acc, whatever.

so, that's a proper servo.

[dany21359]

@MrWreeve what ever i said its still cool

[dany21359]

@MrWreeve what ever

[MrWreeve]

@dany21359 It doesn't have to stop to be a servo motor, it only has to give position feedback. Any motor with an encoder can be a servo. The easiest example of servo motors of this kind are those used in heavy machine tools. There are even special cog-less varieties that operate at low speed without 'jerking'

[dany21359]

@MrWreeve because a proper servo doesent keep spinning. just get a few more gears and make it so it stops at a point. nut its still pretty cool

[MrWreeve]

@dany21359 Why do you think it isn't a 'proper' servo?

[dany21359]

@MrWreeve its not a proper servo but its still cool

[MrWreeve]

@dany21359 You described a subset of a larger category called servo motors.

[dany21359]

Dude that's not a servo but it's pretty cool servos are made out of a : potentiometer ,a motor , 3-4 weird red components , cables , and a ic chip