A multi-buy set of four heavy duty compression springs
38mm long with 8mm internal diameter to fit over shouldered washer M120D or any standard boss for use with standard axles, or fits over a large system axle.
This part was originally included in the Meccano Multikt Crane Set.
The winding drum is driven by the collar (one half of a Dog Clutch)
The collar is fixed to a shaft but the Drum must be against a surface or have a collar attached to the shaft to maintain connection.