When a roller chain is applied, shaft positions could be arbitrarily determined. On the other hand, in principle, follow the illustration shown under. That’s, in case the chain is tensioned horizontally, preserve the best tensioned. Stay clear of vertical transmission every time doable. In an inevitable situation, area the significant sprocket in the bottom irrespective from the direction of rotation.
Once the chain layout is undesirable:
?When the prime is sagging plus the sprocket center distance is short:
As illustrated under, adjust the sprocket center distance shaft to remove the sag.
?Once the top is sagging and the sprocket center distance is extended:
As illustrated below, install an idler from inside to get rid of 
the sag.
?Once the chain is vertical or inclined:
Reduce the additional sag by a tensioner. In this instance, a tensioner that automatically eliminates the sag provides greater effects.
When a pulsating load acts in large pace operation:
The chain’s vibration as well as load affect frequency or chordal action may synchronize to amplify vibration over the chain. Because vibration influences the chain, consider countermeasures to prevent vibration from the following measures:
?Transform the chain speed.
?Raise chain stress. Nevertheless, note that over-
tensioning can shorten the life with the chain. ?Use an idler or tensioner to divide the span
?Install a manual stopper to stop vibration.
Note: Chordal action refers to the vertical motion of chain triggered when it is actually engaged with sprockets.
