There is still significant backlash in these motors, and tiny plastic gears, so these won't solve all the world's problems, but they are certainly affordable and great for education.
Well, I disagree with Gadgetman..
I think the video was great. I believe that's the first time I've ever said that about a Microsoft video.
Usually instructional material will say something like "Use this specific stepper motor, use this particular microcontroller (say, some Arduino), and then use this pre-made library and then you can run your stepper motor". With no understanding or even challenge whatsoever.
Instead, after watching the video you a) actually understands how that stepper motor works, and b) you know exactly not only how, but also why it works (which means that you can figure out alternatives), and c) you can then do the fun part yourself, which is writing a program on your favourite mcu (or sbc or your old Apple II, if you add I/O) and actually make it work. Because you know exactly what's needed.
For [insert name of favorite deity here]'s sake, did he have to repeat the model number on the stepper and IC all the time?
That kind of stuff really rubs me the wrong way.
Another cheap (99 cents) stepper from China, I ordered one, who else will answer the call? This one has a leadscrew. Different form factor, must have one.
OK erco you got me again. Dang that thing would have saved me a bunch of work last year. Might be worth taking another stab at the automatic gemstone drill I couldn't quite get to fly.
I'm using one now to control a bipolar stepper I've had since the early 1990's. My project to build a driver out of discrete components flopped but the eBay china board works like a charm.
Not just H-bridges. Back in my early days with the Propeller I spent a couple of lost weeks trying to get it to read the output of a strain gage load cell, which is a Wheatstone bridge. No joy. Recently I bought a batch of 5 for $10 HX711 boards, for which there is an object in the OBEX, and had a working scale in half an hour. These days Loopy is quite right.
Hey. That thing's gonna come in handy some day! Just you wait. You'll need micro-positioning for something, I'm sure. Think facial expressions for animatronics dolls for the twins.
(I'd probably lose that thing in my bench clutter. Wow! It's so tiny!)
Comments
And second there is this, which extols the merits (2.5x more torque) of hacking these unipolar motors into bipolar units. Sounds VERY advantageous!
http://www.jangeox.be/2013/10/change-unipolar-28byj-48-to-bipolar.html
There is still significant backlash in these motors, and tiny plastic gears, so these won't solve all the world's problems, but they are certainly affordable and great for education.
Seems like it's time to dig out some L298N boards and make some bipolar stepper motors.
Thanks for the info erco. I just purchased a few more of these motors.
Boring stepper motors, evil step mothers, it's enough to traumatize our youth, (uni)polarize their views and give "step" a bad name.
Why won't Billy take that first "step"?
I think the video was great. I believe that's the first time I've ever said that about a Microsoft video.
Usually instructional material will say something like "Use this specific stepper motor, use this particular microcontroller (say, some Arduino), and then use this pre-made library and then you can run your stepper motor". With no understanding or even challenge whatsoever.
Instead, after watching the video you a) actually understands how that stepper motor works, and b) you know exactly not only how, but also why it works (which means that you can figure out alternatives), and c) you can then do the fun part yourself, which is writing a program on your favourite mcu (or sbc or your old Apple II, if you add I/O) and actually make it work. Because you know exactly what's needed.
Good stuff.
For [insert name of favorite deity here]'s sake, did he have to repeat the model number on the stepper and IC all the time?
That kind of stuff really rubs me the wrong way.
-Tor
http://www.ebay.com/itm/1-Pcs-DC-5V-2-Phase-4-Wire-Micro-step-Motor-Mini-Slider-Screw-Stepper-Motor-JHXG-/141770218365
Or get an L298N, cheap & bulletproof for higher power (for fast action on a stepper, use higher voltage, maybe 9-12V on this 5V-rated motor).
http://www.ebay.com/itm/L298N-Dual-H-Bridge-DC-Stepper-Motor-Drive-Controller-Board-Module-For-Arduino-/301763672478?hash=item464284399e
http://www.ebay.com/itm/5-Pcs-L9110S-H-bridge-Stepper-Motor-Dual-DC-motor-Driver-Controller-Board-for-/221792873271?hash=item33a3e2ab37
I'm using one now to control a bipolar stepper I've had since the early 1990's. My project to build a driver out of discrete components flopped but the eBay china board works like a charm.
Isn't that funny? The forum is rife with DIY H-bridge woes. Loopy wisely said "just wait until someone can sell you what you need"... http://forums.parallax.com/discussion/161892/h-bridge-speed-issues
http://www.ebay.com/itm/151623924519
(I'd probably lose that thing in my bench clutter. Wow! It's so tiny!)
-Phil
Maybe it's time for a bench clutter photo contest!