Output torque required

[sankposh]

Could any one suggest solution for my details specified:
I have a Stepper motor of 220Kgcm
iam using gear box of 1:20
than what will be my output torque after the gear box
any calculated formula

 

[chuckey]

A gearbox is notionally lossless, so it trades torque for speed so speed variation is 20X, so torque is 1/20. Real gear boxes are not lossless their efficiency varies between 95 and 50% depending on their design. So in your worst case you could only be getting 1/40 of the torque.
Frank