Quick & Easy way to draw and get dimensions of an existing part

Quick and easy way to draw and get dimensions for duplicating or producing new parts with out CAD. The graph sheet in this case is with 1mm resolution. 

Place the part on the graph sheet and trace it along. 

Stepper Motor Calculations

IPM = (Frequency * 60) / (Turns Per Inch * Steps Per Revolution * Microsteps)

Configuring software steps per unit:

This variable stores how many steps to take to move the X axis 1 inch. You will need to set this as accurately as possible if you want your machine to be accurate. There are two ways to set it:

1. Move and Measure - slap a pen or marker on as a tool head and draw a 1000 step line. Measure it and divide 1000 by the length in inches.
2. Calculate Step Size - this one is the preferred way of doing things. Its rather easy to calculate step size based on your drive mechanism.

For threaded rod type drive systems:

Find your TPI (Turns Per Inch). for example, 1/4"-20 threaded rod means that there are 20 threads per inch single start (aka 20 turns = 1 inch.) Simply take that number and multiply it by the steps in a revolution. With a 400 step motor (200 steps per revolution at half step), it would be 8000 steps per inch.

For belt/pulley systems:

1. Find the circumference of your drive pulley. (remember circumference = 2*pi*r) (say: 2.75")
2. Calculate step size (ie: circumference / steps per revolution) (say: 2.75" / 400 = 0.00625")
3. Divide 1 inch by step size (1" / 0.00625" = 160 steps/inch)

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Steps & Frequency Step Angle: 1.8° Physical Steps Per Revolution: 200 = 360° in a revolution ÷ 1.8° step angle Micro-step Mode: 8th Effective Steps Per Revolution: 1600 = 8 microsteps per step x 200 physical steps per revolution RPM (Revolutions Per Minute): 1000 Steps Per Minute: 3200000 1600 effective steps per revolution x 2000 revolutions per minute Hz (cycles per second): 26666.67 = 3200000 steps per minute ÷ 60 seconds in a minute kHz: 26.7 Hz ÷ 1000 IPM Lead Screw Threads Per Inch: 10 Number of Starts: 2 Turns Per Inch: 5 10 Threads Per Inch ÷ 2 start, so it takes 5 revolutions to move 1 inch IPM (Inches Per Minute): 200 = 1000 RPM ÷ 5 Revs Per Inch

Source  : http://www.probotix.com/stepper_motor_calculations/

Required Motor Accuracy to Achieve Targeted Positioning Accuracy

When a 10mm lead (10mm/rev.) ball screw is selected for required accuracy of ±0.01mm, the following equation can be used to obtain the required motor accuracy (resolution).