Z axis gear reduction
 

Unfortunately I didn’t find this site before I built my machine. I have been running direct drive and now want to add gear reduction. I looked at the Oriental site, http://catalog.orientalmotor.com/vie...easuresortid=0, and they carry gearheads at a price that doesn’t make it worth the effort to make my own.
Here are some of the assumptions I am working on.
1. I doubt that I will run at more than 300 IPM.
2. A 1.1” diameter pinion gives 3.3” of travel per revolution.
3. Steppers can run at 2000 RPM
4. At 100 RPM I get 330 IPM
5. 7.2:1 covers my projected needs for X and Y
6. 150:1 gives 44 IPM max which should be fine for Z
7. Will 150:1 give enough holding power to hold Z in power off condition? If so then the gas lift would not be needed and frees me from the 7” limit of the gas lift.