I'm putting together a pen plotter that uses 2 stepper and 2 servo motors.
From what I can find online, the power requirements are:
Stepper motors (sm-42byg011-25) : 12V, 0.33A
Servos (SG90) : 5V, 0.5A
The steppers will be driven by two EasyDriver modules and controlled by an Arduino Uno (or maybe a Nano).
I have a few questions (I have no formal training in electronics!):
- Can I run the steppers at higher voltage?
I read that it would give better performance at high speed. Maybe go to 20V?
- How do I work out the total current draw?
Are the values on the datasheets typical? max? Do I just add them up, 2x0.33 + 2x0.5 = 1.66A
I suppose I can just get a 2A or 3A power supply and it should probably be enough (based on what other people have used on similar projects)
- Isn't it odd that the tiny servos draw more current than the larger stepper motors?
- I'll need a step down module to go from 12V (or higher) to 5V. Anything to watch out for?
From what I can see even the cheaper ones on eBay can supply 2A, so that should be ok for the 2 little servos.
- I'll probably power the Arduino from USB. Is that ok?
- Will I need any heatsinks for anything?