# How do I mechanically convert 200 steps into 360 discreet degrees?

I have a Nema 17 stepper motor that does 200 steps per revolution, or 400 800 and 1600 micro-steps if in micro-stepping mode for convenience sake I would like to somehow translate the 200 steps into 360 steps. What gear ratio / micro stepper configuration do I need to convert 200 steps to 360 steps.

Update

If anyone wants an easy way to create an involute spur gear, I found this page, converted the to DXF in illustrator then extruded in Rhino! http://geargenerator.com/

• 20t/36t gears or toothed belt pulleys. Oct 1 '16 at 21:57
• Typically wouldn't a stepper motor be controlled by some sort of programming/software? Program a unit converter between gradians and degrees before it sends the signal to the motor. Oct 2 '16 at 16:05

## 1 Answer

You want a transmission with a ratio R such that $R \cdot 200 / 360$ gives an integer number of steps per degree. Then in controlling software you can program it to take e.g. 5 steps to move one degree.

As Brian Drummond mentioned in a comment, 36:20 is one possible ratio, giving 1 step per degree.

Some other options:

• 9:5, equal to 36:20 except smaller gears.
• 9:1, gives 5 steps per degree, so greater torque but slower speed

As to how to implement the transmission, you can do it with either gears or with belts. Some of the ratios above are very basic, I'm sure you could even find a premade 9:1 part.