Stepper with driver.- source commentary please.

vaclav_sal

Does anybody has an experience with this source?
I am collecting parts for my first stepper controlled application.
I understand steppers are not designed for torque, so I will have to couple this motor with suitable reduction / transmission.
I am looking for easy control and torque, positioning/repeatability and speed is secondary.

http://www.ebay.com/itm/Stepper-Motor-5V-4-Phase-5-Wire-Driver-Board-/261118237469?pt=LH_DefaultDomain_0&hash=item3ccbdc1b1d

Yanomani

Hi vaclav_sal

There is an entire thread devoted to this kind of stepper motor.

http://forums.parallax.com/showthread.php?141149-3-Stepper-Motor-amp-Board

I'm sure there is the best place to get all the answers you want.

Hope it helps

Yanomani

prof_braino

vaclav_sal wrote: »

Does anybody has an experience with this source?

I didn't order from that individual, but I imagine all the ones from the same location with free shipping are in the same office.
I also imagine they are wearing rags and chained to the desks, and make 1% as their cut, if they lose a customer, their family will starve. But I have a vivid imagination.
Point is, if they have free shipping, and offer a bunch of other stuff you want too, AND they have high rating, it is probably worth the risk and a cheaper source thatn anything local.
Even if they game the ratings, at least it shows they care enough to put in the effort, and have a likelihood of following through.

So far all my order from Shenzen(?) were satisfactory. I haven't tried any that said simply "china"

vaclav_sal

Thanks for replies.
I did find some steppers with gearboxes also. Lacking the experience and any means to measure torgue I guess I;ll have to just test it for smoke.
I did find some miniature geared motor, but without a controller and much more $.
Since I need to stop and reverse the direction when the devices - tunning capacitor and roller inductor - are at the end, using stepper to count revolutions is obviously less hardware than any other way.

Yanomani

Hi vaclav_sal

If you are looking for a solution like this one:

http://www.tomthompson.com/radio/Antenna%20Tuner/tuner.html

then maybe you can use a DC motor with tachometer feedback like the one Beau Schwabe cited in this thread:

http://forums.parallax.com/showthread.php?143183-DIY-motor-feedback-from-mouse-parts./page3

whose direct link is:

http://www.ebay.com/itm/251172557043?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648

I'm suggesting you to use any kind of feedback you can get because I don't know your exact application. Without any feedback you can't be assured that your tunning capacitor or roller inductor hit the point that you supposed they will be.

Yanomani

vaclav_sal

Yanomani wrote: »

Hi vaclav_sal

If you are looking for a solution like this one:

http://www.tomthompson.com/radio/Antenna%20Tuner/tuner.html

then maybe you can use a DC motor with tachometer feedback like the one Beau Schwabe cited in this thread:

http://forums.parallax.com/showthread.php?143183-DIY-motor-feedback-from-mouse-parts./page3

whose direct link is:

http://www.ebay.com/itm/251172557043?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2648

I'm suggesting you to use any kind of feedback you can get because I don't know your exact application. Without any feedback you can't be assured that your tunning capacitor or roller inductor hit the point that you supposed they will be.

Yanomani

Thanks for helpfull references, I appreciate that.
I am not concerend about the position of either C or L , I measure SWR externally to the coupler. I just need simple "end of the run" indicator. I understand that DC motors have pronounced stall current but not sure if stepper motor can be monitored same way.

Yanomani

To avoid surge currents and oversized power supply designs, optical switches are in the play everytime I can use them. By the use of simple plastic brackets fixed to any moving part they will generate a clear logic transition into a microprocessor input to signal that the attached mechanics reached an endpoint. Very easy to setup and adjust, great for half or multi-turn capacitors, inductors and potentiometers.

Hope it helps.

Yanomani