I am in the process of building my first CNC. I am planning to use a 1/4" thread rod. I am only aware the rod has the "standard" thread on it. I do not know anything about the pitch and other terms I have read about before.

I would like to know how to calculate the horizontal displacement and in general, How or where can I get all the theory of the math involved using the 1/4" rod?

Thanks all

1/4"-20 is 20 threads per inch. Each rotation of this screw will yield .050" displacement. You have to rotate it 20 times to move one inch. Divide 1 inch by the number of threads to get the displacement. 1/20=0.050".

So - if you want to get just 50IPM from your machine, you would have to spin this screw 1,000 RPM, right? 20 turns per inch, 50 inches to travel = 1,000 turns per minute.

How big is your machine going to be? What speeds do you want to reach?

Scott

Standard threaded rod is 1/4 x 20. The 1/4 number is the dimension of the rod; the 20 specifies that it is 20 turns (threads) per inch. That means that the rod will have to rotate 360 degrees 20 times to travel a distance of 1 inch.

The above example is standard for all threaded rod.

Hope this helps.
Jerry

there's an echo in here..... :D

Scott

There were NO posts when I started to respond to the question. Guess we both answered at the same time.

Jerry