Whenever a roller chain is utilized, shaft positions could be arbitrarily established. Having said that, in principle, comply with the illustration shown beneath. That is, when the chain is tensioned horizontally, hold the top rated tensioned. Keep away from vertical transmission whenever possible. In an inevitable case, place the large sprocket with the bottom irrespective of your path of rotation.
Once the chain layout is undesirable:
?Once the major is sagging and the sprocket center distance is short:
As illustrated under, modify the sprocket center distance shaft to reduce the sag.
?Once the leading is sagging and also the sprocket center distance is prolonged:
As illustrated beneath, install an idler from inside to get rid of the sag. 
?When the chain is vertical or inclined:
Eliminate the extra sag by a tensioner. In this instance, a tensioner that immediately eliminates the sag gives greater effects.
When a pulsating load acts in large speed operation:
The chain’s vibration plus the load affect frequency or chordal action could synchronize to amplify vibration on the chain. Since vibration has an effect on the chain, consider countermeasures to prevent vibration from the following measures:
?Change the chain pace.
?Raise chain stress. Having said that, note that over-
tensioning can shorten the daily life from the chain. ?Use an idler or tensioner to divide the span
?Set up a guidebook stopper to avoid vibration.
Note: Chordal action refers to the vertical movement of chain triggered when it can be engaged with sprockets.
