# Reduction Gearbox Calculation question

If Have have the torque needed to turn the input shaft of a 500:1 Gearbox with no load, can that information allow me to calculate the opposite. I want to know the torque required to turn the output shaft.

What I mean is, if you were to apply the force to the output shaft. In other words, use a Reduction gearbox in reverse.

This has been driving me nut to figure out if it is as simple as taking the torque required to turn the input shaft and multiply it by 500 since im talking a 500:1 ratio...

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Thanks
Chris

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## Answers and Replies

Nidum
Science Advisor
Gold Member
This has been driving me nut to figure out if it is as simple as taking the torque required to turn the input shaft and multiply it by 500 since im talking a 500:1 ratio...

No - not for a ratio as high as 500:1 .

No - not for a ratio as high as 500:1 .

If not then why and how would I calculate it?

JBA
Science Advisor
Gold Member
The difficulty is that the friction loading due to any bearing friction and any contact friction between the gear teeth is going to be multiplied at each stage as well.