People have invented a variety of squirrel baffles to prevent squirrels from climbing into bird feeders and helping themselves to the buffet meant for the birds. Most baffles either make a surface too slick or unstable to climb on or place a barrier that the squirrel can't climb around. However you decide to protect your bird feeder, make sure it's mounted far enough away from solid objects so squirrels can't jump directly onto it without climbing past your baffles.
Remove the bird feeder from the top of the post if it's already mounted there. Measure the diameter of the post.
Cut a length of metal stovepipe or PVC pipe that's 2 to 4 feet long and at least 4 inches wider in diameter than the diameter of your post, though larger is better. Use a saw.
Cut a square of 1-inch treated wood or plywood that's an inch longer on each side than the diameter of the stovepipe or PVC pipe. Set the pipe upright on it, approximately centred, and trace the outside of the pipe with a pencil.
Screw four 2-inch metal L brackets to the board with a screwdriver so they're spaced evenly around the circle you traced and the upright part of the Ls would touch the pipe. Drill pilot holes for screws to attach the Ls to the pipe, but don't screw them in yet.
Slip the stovepipe or PVC pipe down over the bird feeder post, then mount the wood square centred on the top of the post in the same way you'd mount the bird feeder, either nailing it to the top of a wooden post or bolting it to a metal post with a flange or bracket. Mount it with the L brackets on the underside. Slide the stovepipe or PVC pipe up the post so it fits between the Ls and screw it in place. Mount the bird feeder on top of the board.
Tie one end of a 4-foot cord to the bird feeder. Tie a knot in the cord about 6 inches above the bird feeder.
Thread the cord through the centre hole of an old vinyl record and tie another knot 3 inches higher. Thread the cord through another record, tie another knot and repeat until you have four or five records on the cord.
Tie the other end of the cord to the bird feeder's support so the records dangle between the bird feeder and the support.
Cut 3-inch lengths of 2-inch-diameter PVC pipe and string them on a horizontal cord to protect the hanging bird feeder further. Use this cord as the support for the hanging bird feeder. As the squirrel tries to walk on the pipe, it will rotate, dumping the squirrel off. If the squirrel does reach the middle, the record baffles will prevent it from climbing or jumping down to the feeder.