Thread: Shaft couplers
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Unread 24-01-2003, 08:51
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Quote:
Originally posted by KennethToronto
Is there anything inherently wrong w. using a 5/16" set screw coupling to "extend" the length of the shaft?
It depends on how you define "inherently wrong". There is nothing illegal or immoral about doing so.

But as Woodie has said so often "Set screws inhale audibly". Basically set screws are ok to use for holding a key in place or possibly keeping a lightly loaded gear or sprocket from drifting on the shaft. They should not be used to transmit significant loads. Since this application is apparently for a drive, the loads will be significant.

Think about set screws for a moment. It doesn't seem all that great an idea to use an inclined plane (screw thread) to generate a normal force that is in turn used to generate a shear force that resists a torque. Dimpling the shaft can help, as it greatly increases the shear force geneated by the normal force. But a set screw and dimpled shaft are no match for a keyed shaft and sprocket or gear.
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