Calculating Torque for Crane Movement on Rails | Step-by-Step Guide

[Bronka]

Hi,
I am trying to solve a problem.

I want to try to calculate the torque needed to make a crane move on rails.
I attached simple drawing of a crane. i want to calculate torque needed for each one of the four wheels so i could try choose proper electromotors and reducers.

I don't need exact calculations, i want some guidance at how it is calculated.

P.S. sorry for my English, not native language but trying hard.
P.P.S. dimensions in drawing are in mm.

 

[NascentOxygen]

Hi Bronka. http://img96.imageshack.us/img96/5725/red5e5etimes5e5e45e5e25.gif

I don't think you can arrive at a reliable figure, due to lack of data. When traveling at a steady speed, the driving torque is entirely dependent on friction (and also wind/air resistance, in light of the significant size of the structure). But on top of this, to give the crane an acceleration from standstill, you will need extra short-term torque. It's 10 metres tall, is it?

A very practical person with experience of large cranes would be able to give a reasonable estimate, but this would be based on his experience, rather than data.

In short, not enough information! http://physicsforums.bernhardtmediall.netdna-cdn.com/images/icons/icon6.gif