7.1.2.1 Chain Slack
The chain slack that you can move by hand (length SS′, see Figure 7.4) should be about 4 percent of the span (length A-B) unless one or more of the following conditions apply:
- The center line of sprockets is vertical or almost vertical.
- The center distance of sprockets is more than 1 m.
- The chain is subjected to heavy loads and frequent starts.
- The chain is subjected to suddenly reversing loads.
If one or more of these conditions apply to your operation, make the chain slack (length SS′) about 2 percent.
Figure 7.4 Chain Slack
