Step 1: Define Speed in RPM (convert to steps/second if necessary
- RPM was chosen because Arduino's stepper library interprets speed in RPM
- Max frequency
Step 2: Determine the time it'll take for the motor to travel to the appropriate distance using the specified speed
Step 3: Test your predictions and see if during x time at y speed, motor is able to travel z steps (Values can be calculated depending on what values you chose for your speed and number of steps to travel)
- To test this: set up the tensile tester like this: (insert picture here)
- Change the code to meet your specified speed and time (See code here:)
- Aspects highlighted in red are the lines of code you change
- Note: Want speeds to be high because tried it with low speed, it doesn't move much
- Frequency of load cell should be at least 100 Hz (1/s)
- Place tester on a ruler and zero it (set the mounting block at 0)
- Set up a timer using your phone or any other form of a timer
- Run code and start timer
- Stop timer when code is completed and observe time/distance traveled
- Note: With time, remember to account for delay time b/c code will stop at the line of code for whatever time you specify
- Check if results make sense in relation to specified distance and time and if it correlates to the correct/set RPM
Step 4: Once the optimal speed/frequency for the motor is found input it into the code which combines its functionality with the load cell and verify it works the way it should when connected to the motor.
NEMA 17 Motor Notes:
Definition of Torque:
- r x F (r=distance, F=force)
- moment of force or turning effect; rotational equivalent of linear Force
- tendency of F to cause or change rotational motion of body
- Twist or turning force of object
- Units of Force= N*m
Holding Torque: amount of torque needed to move motor one full step when windings are energized but rotor is stationary
Windings: wire placed within coils, energized coils are compressed?????
Detent Torque: torque at maximum load that's applied to shaft of motor which is unexcited without causing continuous rotation
Radial Force= load acting perpendicular to longitudinal axis
Axial Force=load acting parallel to longitudinal axis
Moment of Inertia Definitions:
- I= L/W
- L= angular momentum
- W=angular velocity
NEMA 17 specifications can be found in this link:
Torque and Speed Relationships:
High speeds= lower torque
Smaller Distances with higher speed should be okay.
For more info look at this link: https://www.motioncontroltips.com/torque-equation/
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