I am just getting started using my arduino and learning quite a bit. For my first project I would like to turn a carousel to specific intervals upon pressing a button. From my research it sounds like a stepper motor is what I need. The carousel itself would not be heavy and I plan on turning it with a system of gears or a belt. The motor would only need to turn the carousel, not lift any weight. After I get the programming down to turn the carousel with push button I would like to move onto controlling the motor with a small web server.
My questions:
I would like to learn how to hook up the stepper without a motor shield/driver. Is that going to lead to a lot of wasted time/money? What additional components would I need (besides a breadboard, wires and resistors that I already have)? I would like to order everything online at once instead of getting the motor and then finding out I need to wait another week or two to order other components. I am not against getting the motor shield all together, I would like to learn without taking big shortcuts though.
With the smooth shaft, whats the best way to affix a gear cog onto the end so it will remain in a fixed position? Tips advice would be appreciated. Also I assume without the motor shield I would have to find a way to hook up an alternate power source?
If I want to eventually use an ethernet shield to control this motor can I even do that if I have the motor hooked up through a motor shield? I don't know how many of these shields you can stack. Maybe its only one at a time? Also, would I need to register a domain to run the web server from? I'm not too sure about this part. Having to pay to register a domain might affect my decision to use the ethernet shield.
I really appreciate any help you can offer to get my project off the ground and running. Sorry if I left out any important info, I am still really new to arduino. Thanks!
If you want ease of driving then that's the wrong motor (its bipolar only since it has 4 wires). Unipolar motors can be controlled from 4 pins with a simple Darlington array (ULN2803 or similar). For a bipolar motor dual H-bridges are needed.
Unipolar motors have 8 or 6 or 5 wires - the X and Y windings are centre-tapped and brought out so that the two halves of each winding can be driven independently, enabling a reversal of magnetic field without a full H-bridge being needed.
If your "gear cog" has a hub with a setscrew you will want to file a flat spot on the shaft for the setscrew to land on so you don't need to overtorque the setscrew (and ruin the screw threads). You might also find a gear that accepts a "d shaft" that you could use -- it would just take a lot more filing of the shaft. And of course if the gear has a nice tight fit on the shaft you might not need to do anything at all.
If you look up the shields in question on shieldlist.org it will show you which pins each shield uses. In order to be stackable you can't have the same pins in use on any two shields. You can usually get fancy with wiring around the problem; it's just not as neat.
With respect to registering a domain, no this is not necessary. You can address the board with an IP instead. Of course this question dives into computer networking and a bit out of scope of the Arduino forum.
You probably need/want a couple of things with your carousel, like limit switches at each end of travel (just in case) and some zero-point sensor. This way you can always initialize by goto 'Home" and start from there.
Some mechanical systems like this use the limit switch as 'home' detection by driving until the limit switch stops the movement, sensing the limit switch, then overriding the limit switch (relay etc) to get the movement to a starting position.