Doing the twist

A low cost machine can produce ‘barley twists’ on wooden posts in a single pass by slowly rotating a piece of wood while moving a router along a pair of rails using a lead screw and a variable speed drive. The ‘Pro-Am’ is the brainchild of Paul Nolan, a professional carpenter based in Charlton in South East London. One of his specialities is to manufacture special posts – particularly designs incorporating barley twists and slots – out of unusual woods. “I made it because there was nothing suitable on the market to make the parts I wanted to produce,” he said. He made his first demonstration unit a few years ago and is currently using his Mark IV version, gradually improving ease of use. The work piece normally starts off as a square section piece of timber, and is either held fixed, by locking one of 16 dimples on the chuck circumference, or rotated at a steady speed of 30rpm. The router, a 3.5HP unit supplied by Freud Tooling in Leeds, is mounted between two round rails and driven down the length of the machine by a lead screw driven by an induction motor and variable speed drive. The inverter is supplied by CJ Controls in Swansea, and is rated at 373W. The tool is equipped with limit micro switches, but operation requires an operator. Making a barley twist first requires rounding off the timber, followed by a change of router tool and insertion to make the ring at one end. The twist then happens naturally when the variable speed drive is engaged. Slots are made by holding the workpiece in a fixed position. The ‘Mark IV’ machine makes parts 1m long and has a chuck able to accommodate 75mm wide pieces of wood. The Mark III has been retained for large parts. Nolan says that a Mark IV machine costs about £800 to make and he envisages selling it at around £3,000 – about one-third that demanded by makers of its nearest competitors. He has had numerous orders placed, but has never been able to fulfil any of them. Some improvements to the design have been recommended in a study produced by Greenwich University. The machine meets the requirements of all European Norms and produces a good finish on woods as varied as MDF, old mahogany, teak and softwoods. The design is patented and protected by copyright registration. While Nolan makes good commercial use of his machines, he has yet to find a partner to put it into manufacturing production. His last collaboration with a government backed agency, ended when he discovered that it had gone into voluntary liquidation. Pro-Am Technologies Email Paul Nolan Pointers * Machine uses a simple variable speed drive and lead screw, coupled with a slow main axis rotation to produce the twists * Machine produces commercial products but a partner is needed if the machines are to be made in quantity