NOTE: This topic relates specifically to downstackers; for general chain tension instructions, follow this link: Adjust Chain Tension

 

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Since the downstacker has four chains on the operator side and another four chains on the non-operator side, it is important to always adjust the tension for each set of chains using the tightest chain. Chains are not always exactly the same length and chains stretch differently. Using the tightest chain will ensure no chain is too tight. Chains tensioned too tightly cause stress on the shaft, bearings, and gearbox.

 

The proper slack on the tightest chain should be 2% of span; slack should be measured halfway between the span. Span is defined as the distance between the drive sprocket and the driven sprocket.

 

The downstacker chain span, from sprocket to sprocket, is approximately 35 inches. Using the 2% guide, 35" of span translates to .7" of slack  (35 X .02 = 0.7), or roughly 3/4". The measurement for slack should be made 17.5" between the sprockets.

 

Care must also be taken to ensure the jack bolts are adjusted equally on the upstream and downstream side of the machine, ensuring the shaft is not on an angle.