Calling on Thern Stage: Maximum Drum Length on a Roll Drop Machine

What’s the maximum drum length on a Roll Drop Machine?


The maximum drum length available on Thern’s Roll Drop machines is 46 ft.  Thern offers two models of Roll Drop machines, the RD5 uses a 5.56” diameter (O.D.) aluminum roller tube, and the RD8 which uses an 8.63” diameter tube.  Each has a maximum drum length that is defined by the allowable deflection of the tube.  The chart below provides information on the working load limit (WLL) of Roll Drop machines based on the model and tube length.  The maximum length of our RD5 is 34 feet, with a WWL of 50 lbs, adequate for lightweight fabrics like scrim and muslin.  The maximum length of the RD8 is 46 feet, with a WWL of about 120 lbs.

On the chart below, a model RD8-40 is listed.  This is a 40-foot long roll drop machine with an 8.63” diameter roller tube.  The chart lists a WWL of approximately 380 lbs.