.75 pitch using mini lathe

[yeorgjx]

I wanted to make (and made) an ER11 chuck.
This topic helped a lot (thanks) http://www.homemodelenginemachinist.com/index.php?topic=11328.msg163528#msg163528
The problem was that my lathe didn't show 0.75 on the thread instructions.
I saw that as greater number of teeth in pinion A bigger the size of the pitch to be machined.
I also noticed that for step 1.5 was needed same number of teeth on the gears A and D.
So I had to use the 1/2 amount of the teeth of pinion D for pinion A.
The solution (based on the gears I already had) was A 30,B-C 35 and D 60.

Maybe the Chinese did not indicate because the 0.75 can hardly be matched ...(third photo)

 

[bp]

If you go to the Little Machine Shop website, they have a changegear calculator, try here.......

http://littlemachineshop.com/Reference/change_gears.php

all the best!!
Bill Pudney

 

[yeorgjx]

woohoo1
They offer there a great tool...(I am not sure now,I maybe saw that on the past when not interested to make a thread and because of my panic when didn't show the desired .75 in the instuctions I didn't remember it)
Also it seems that I don't have all the gears.I will remember it next time I need to make a thread.

Thanks a lot,my friend.