The shaft coupler is what I show and describe in my blog post. The other parts you indicate in your annotations were an idea about how to keep the shaft from moving axially within the frame, and aren’t actually working as desired and have been removed.

]]>sorry i am not familier with this mechanical stuff

check the photo

http://img186.imageshack.us/img186/2818/drillplatformfront.png

can u give me the photo of ur machine ???

]]>http://img249.imageshack.us/img249/6279/1002569mid.jpg ]]>

in the plate the

i trying to build x-axis and y axis to my cnc router machine

and other question how you can calculate the steps of the motor ]]>

I use 1/4-20 (1/4″ diameter, 20 threads per inch) because 20 tpi divides nicely into 1000. My circuit boards are laid out in mils (thousandths of an inch), so I want to be able to address 1/1000″ exactly — not a nearby size like 1/800″ or 1/1024″.

Since my motor has 200 steps per revolution, threaded rod with 5 tpi gives me 1000 addressable steps per inch. Any integer multiple of 5 tpi gives me an integer multiple of 1000 steps / inch, so I needed rod with a multiple of 5 tpi.

Of the sizes available at my local hardware store, 1/4-20 was the only multiple of 5 tpi, so it was my choice. That gives me 4000 steps per inch, which is pretty fine-grained control (ignoring backlash and other mechanical shortcomings).

]]>You know I did some blogs and I never get any comments. ]]>