Ball Chain Tensioner

This is a simple device to apply a bit of tension to the motorised ball-chain used for blinds or curtains. This was designed to work with a 3mm ball-chain. It consists of a ‘Hole Side’ and a ‘Thread Side’, screwed together with M3x10 screws and with grooved V623ZZ rotary ball bearing separating the sides. The up and down sides of the chain pass through on the inner sides of the bearings. It should be mounted above the cog-wheel of the motor drive, where it will naturally descend and tilt in the direction of the chain motion, to both pull the chains together and also increase the amount of grip around the cog-wheel. You will need … 2 x M3x10 screws.2 x V623ZZ v-groove ball bearings. Both readily-available from Amazon or AliExpress.