# which is the High Speed motor? DC,Servo,Stepper?

1. ## which is the High Speed motor? DC,Servo,Stepper?

hii, i am designing an application in which i need to turn motor shaft BACK AND FORTH from 0 degree to around 190 degree (any fixed angle between 180-210) at HIGH SPEED AS POSSIBLE...which motor would be best in terms of Speed??..DC,SERVO,STEPPER??. angle accuracy is not necessary..jst need little more than 180 degree...help me.

2. ## Re: which is the High Speed motor? DC,Servo,Stepper?

A DC motor (Johnson motor) will spin quickly when you apply power. Positive, it turns in one direction. Negative, it turns in the other.

You'll need to attach stops, to block it from traveling beyond your desired range of motion.

It will move easily, if something is pushing on it.

If you want it to stay in place, then a servo will do. It will move almost as quickly as a motor. Some (if not all) will give you 190 degrees of movement.

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3. ## Re: which is the High Speed motor? DC,Servo,Stepper?

I think your specification of "as fast as possible" is a bit backwards. What do you really need? What is your budget?

High-speed commercial steppers can do 10K steps per second or more. That is very roughly 36 mS per 180°. High-speed hobby servos can do 120° to 180° in 70 mS or so. I do not have data on the fastest commercial servos, but I suspect they are at least as fast or faster. Is that difference significant to you? Why?

John

4. ## Re: which is the High Speed motor? DC,Servo,Stepper?

i am getting 1400 pulses per minute by a metal detector. i need to make my motor rotate +200 degree forward for First pulse and -200 degree for second pulse and so on....so in one minute 700 times forward and 700 times backward. as the angle is little more than 180 degree i need 700-800 RPM motor for this application.which motor would be the best? and how long pulse i should give to that motor to move 200 degree?

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5. ## Re: which is the High Speed motor? DC,Servo,Stepper?

That's 12 reversals a second. I can't picture making a servo do that for very long. I think it would wear out.

Maybe if you attach an oval cam to the motor shaft? The cam will wobble a stick of wood (plastic, metal, etc.) back and forth.

6. ## Re: which is the High Speed motor? DC,Servo,Stepper?

i m trying stepper motor..using full step sequence for maximum speed..what are the other possible ways to get maximum speed of stepper motor?? what minimum time duration i should give between two pulses?

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7. ## Re: which is the High Speed motor? DC,Servo,Stepper?

I think, the back and forth drive can be much easier implemented with a crankshaft transmission.

Technically, an AC servo motor with high-dynamic vector drive should be able to achieve the motion profile. But that's an expensive solution for a constantly repeated motion. Stepper motor might work too, you need to check the feasible acceleration/deceleration ramps for a specific motor. In any case, a high voltage PWM driver would be needed.

8. ## Re: which is the High Speed motor? DC,Servo,Stepper?

Actually i m getting interrupt pulses from metal detector sensing a metal bolt which is attached to a pulley. That pulley is moving at 1400RPM. so i am getting 1400 interrupt in a minute.now i want to modify the design using these interrupt pulses for application shown in below picture.

here is the application i want to modify.

Attachment 103640

Stepper motor moves the white wheel which moves the pulley attached through belt.pulley is half size of white wheel. Stepper motor having 1.8 degree step angle.I need to move white wheel around 200 degree so that pulley moves little more than one revolution.

now. for first interrupt motor should move 200 degree forward and second interrupt it should move 200 degree backward and so on..back and forth motion...i think minimum motor 800 RPM motor required. so i m looking for a motor and motor-driver suitable for this kind of application.any kind of help is appreciated.thank you.

9. ## Re: which is the High Speed motor? DC,Servo,Stepper?

I understand that you want to synchronize your drive with an external motion. That's of course a reason to search for an electrical drive method. Nevertheless I keep my reservations regarding the implementation effort.

By the way, you see how the bad habbit of cross posting brings up confusing threads...

10. ## Re: which is the High Speed motor? DC,Servo,Stepper?

ya,i am sorry for that. u can see the the image below.

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