[benjamin.w]

Hi,

I've designed a product and I need to build a prototype which includes a stepper motor that mimics the control knob/jogwheel/encoder/dial movements 1 to 1 or close to 1 to 1. So when you turn the control knob/jogwheel/encoder/dial, the motor copies in both directions. The video below demonstrates the kind of control I'm looking for and being obsessed with this, I tried contacting the person behind the video but had no reply. I even offered to buy it from him.

[ame=http://www.youtube.com/watch?v=gwFIW9PmScw&list=UU0F6K1-TFXeeLK0DJVR0SZg&index=9]DIY. Remote Motor - just wired - YouTube[/ame]

I've looking into drivers and existing circuit boards but cant find one that has kind of control. I've seen how to do it with an arduino but dont want to use it or any pc device. The closest I found is in the link below. Its perfect but is a bit jumpy and I've been trying to get my head around why that is and how stepper motors work. My limited knowledge tells me that its jumping in full steps and that other controllers can work in half steps and even less making them smoother.

Simple manual control of stepper motors without a PIC or PC

Its looking like I might have to combine the right encoder to the right controller board and thats where I hit a brick wall. I have only a small knowledge of electrics and am struggling to work out a solution.

I would really appreciate any feedback and help.

Voltage wise, it could be between 5 and 24
Stepper motor wise, what ever works really.

Thanks for your time.

Ben

[CalG]

With a "good" stepper drive. (I like the Compumotor S-6 Or even the M 1xx series, they are old and cheap and plug into the wall)

Coupled with the appropriate motor. (the S drives cover a huge range)

And a PULSE GENERATOR , You are good to go.
In the drive are settings that determine the "steps per revolution" based on the motor selected.

When the steps per rev of the motor match the pulses per rev of the pulse generator, You have the set up you ask for .

Do a search on "pulse generator" often found on machine tool CNC control panels for manually movments.

Cheers

[benjamin.w]

hi calg,

thanks for your message. just curious why you say 'good' stepper driver. are the cheaper incapable of what i ask? i'm trying to keep cost as low as possible and i looked at those drivers and they are to expensive for me. also, how would i connect a control device to it, like an encoder knob. sorry if these questions are super basic, i'm new to all this. thanks for the help really appreciate it.
ben

[007CNC]

The easiest way I can think of is by connecting 2 steppers together.
If you connect two steppers together "correctly", when you spin one stepper, the other one will follow.
The torque will of course be very low, so I dont know if there is any practical application of this connection without additional circuitry, but I think you can throw in a current amplifier in the mix to get it to drive something.
Sure there are other ways of doing this, but this is one I can think of.

[H500]

i'm trying to keep cost as low as possible and i looked at those drivers and they are to expensive for me.
ben

A good driver cost $25 to buy or $10 if you do it yourself. But none will interface directly to an encoder. You will need a microcontroller board with custom code to do that. The board cost $5-$15. The code is trivial and can be done in an hour or so.

[langwadt]

A good driver cost $25 to buy or $10 if you do it yourself. But none will interface directly to an encoder. You will need a microcontroller board with custom code to do that. The board cost $5-$15. The code is trivial and can be done in an hour or so.

a quadrature encoder could possibly control a stepper directly, the coils of a stepper is also driven in quadrature

you'll need a driven that phase input instead of step/dir input

[CalG]

hi calg,

thanks for your message. just curious why you say 'good' stepper driver. are the cheaper incapable of what i ask? i'm trying to keep cost as low as possible and i looked at those drivers and they are to expensive for me. also, how would i connect a control device to it, like an encoder knob. sorry if these questions are super basic, i'm new to all this. thanks for the help really appreciate it.
ben

Good in that, as a new user, if the compnents of motor, driver, power supply, controller and pulse generator are not matched, you will spend a lot more time and money that you might think. I didn't pay more than $85 for any of the S6 drives I have. (I thinks it's 7 or eight at the moment, some of them "as new in the original box")

A packaged drive like a Parker M series, S or SX series takes 4 wires to the pulse generator (Step and direction) a line cord, and a motor connection cable.

In the days before "software" , a TRANSLATOR was placed between the pulse generator and the motor. A translator inputs raw pulses, and output timed moves and accelerations and decelerations. It was the brains of the driver. (I've got one of those also ;-) I assumed your 1:1 application is low speed without concern for accel ramps or even lost steps. Certainly a manually turned pulse generator could care less.

A very coares resolution quadrature encoder could be made to work. The SX drives from Parker have what is termed "following mode" just for such applications. Those drives even offer electronic gearing. I would not choose a quadrature devicehowever. Stick with the pulse system unless you happen to be handy with converters. It might be difficult to locate an encoder that gives 1:1. Pulse counts of 200 per rev hmmm...I don't know.

Not a sales pitch for the legacey Parker products, but I like them. I am sure there are others just as useful.

I tried the $10 specials, I'm not smart enough to use them. And then you need to make a box to put them in...... blah...blah....

Keep shopping! You will find what you need.