Simple stepper motor project

Thread Starter

Brian Krupicka

Joined Nov 1, 2014
38
I am trying to help my grandson with a very simple stepper motor project.

Two separate operations:

1) Toggle a switch ON and have the stepper motor continually rotate in one direction.

Once a 555 pulse generator is powered on, it would pulse a multi-poll relay, which would operate the stepper motor.



2) Press a button and have the stepper motor index.

Each time the push button is activated the multi-poll relay would operate the stepper motor.



Would this work? Any additional comment would be helpful.

Thank you
Brian K
 

shortbus

Joined Sep 30, 2009
7,248
Don't see it working. Stepper motors need a driver, to give the correct sequence of signals to the motor. While there are many circuits out there to make them, many don't work. The fastest and most inexpensive that actually work, are really cheap on Ebay. Like this one, just the first that came up in Google, may even be cheaper ones. https://www.ebay.com/i/261823467014?chn=ps&dispItem=1
 

Thread Starter

Brian Krupicka

Joined Nov 1, 2014
38
Thank you for your comments. I am learning a great deal.
The project is to rotate, in one direction at a low speed, a model train engine turntable.
I will use a 555 pulse generator (set to a ½ second) to drive the “Step” pin on an Easy Driver.
This will be accomplished by pressing and holding an N/O push-button, until the engine turntable reaches the desired position. (Note: Micro stepping will come later, once, I get the basic operation working. However, I feel MS1 and MS2 maybe will be wired to +5V.)
A second on/off toggle switch connected to the “DIR” pin on an Easy Driver will control the direction.
See attached drawing
Comments are greatly appreciated.
Thank you
Brian K
 

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Thread Starter

Brian Krupicka

Joined Nov 1, 2014
38
This is the stepper motor I ordered. Do you see any issues?
The stepper motor is:
Model: ROB-09238
Manufacturer: SparkFun
Stepper Motor with Cable Features:
  • Step Angle: 1.8° + /- 5%
  • 2 Phase
  • Rated Voltage : 12V
  • Rated Current : 0.33A
  • Holding Torque : 2.3kg per cm (0.23N.M)
  • 5mm Diameter Drive Shaft
 

philba

Joined Aug 17, 2017
960
If you haven't already ordered the stepper driver, consider using one of the pololu drivers, they are loads cheaper and use the same chip as the big easy driver. The main difference is the BED has a voltage regulator on it.

I'm sure other will disagree but I would tackle this project with a microcontroller - an arduino nano is really cheap and works great. The problem I have with every stepper driver+motor I've ever used is it takes some experimentation to get everything working (step rate, pulse width, etc). And if you will be doing microstepping, you will definitely want to experiment to find the sweet spot of the driver+motor. With a micro it's quick to make changes, with a 555 you have to fiddle with component values. Not that it's a bad thing, just takes me longer to get things where I want them.
 

Thread Starter

Brian Krupicka

Joined Nov 1, 2014
38
Thank you for the recommendation and response.
We will try this driver as well with the 555 approach, since we do not have the expertise for programing a micro-controller.
Brian K
 
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