Robotic welding cells prove to be good investment
Robotic welding cells prove to be good investment
Keywords: Robots, Welding
Two production cells based around Comau robots have been running in a Merseyside factory, trouble free, for nearly 10 years. The initial investment was calculated to pay back within 2 years – so the 8 years of production have been a “good investment”, and they have no intention of stopping. The initial investment exceeded £300,000 and proved well spent for the forward thinking company, a model to others with a check-list of issues for automating processes, including payback, labour, service support, floor space and change in philosophy.
Glen Dimplex Cooking in Prescot, the UK's only independent cooker manufacturer, received an immediate 42-fold production saving with the introduction of the two Comau Raven robotic cells (Plate 1) for the manufacture of oven struts (seven fold production increase with one-sixth manning), which has continued as a benefit, to become the accepted norm.
Plate 1A typical twin robot spot welding cell, supplied by Comau as a Raven standard cell
The cells are identical turntable-based standard configuration and located adjacent to one another. Each incorporates a Comau SMART 125 kg capacity articulated-arm, six-axis CNC robot capable of positioning the spot welding gun to a repeatability of 0.3 mm. Welding time is 1min per pair of struts per cell,so each produces over 50 struts per hour based on a cell efficiency of 85 per cent, which considers all stoppages including operator breaks.
“This sevenfold productivity increase with one-sixth of the previous staff means that the system paid for itself just 20 months from date of purchase, the further years operation effectively had zero capital cost,”confirmed Graham Bonner, Purchasing Director. “We calculate that we run the robot cells for between one-third and one-quarter the cost of operating our previous manual welding facility. Moreover, had we not adopted robotic welding of these components, we would have needed a line of 20 manual welding machines working three shifts, with expensive staffing and space overheads which that implies.”
Apart from speed and reliability, flexibility is the other key to the success of the robotic cells. Glen Dimplex manufactures in batches of anything from 50 or more under the brands of Stoves, Belling and New World for delivery to major retail outlets, for example, down to one- offs, which may have been ordered directly by members of public. A 24h turnaround for most orders is the resulting high level of customer service which is currently able to provide,with same-day shipment in some eases, organised under the ubiquitous Kan Ban discipline backed by just-in-time deliveries by suppliers.
Comau Robotics is part of the Comau Estil Group in the UK, and is based in Shrewsbury, Shropshire. Comau is a wholly-owned subsidiary of FIAT, and is the largest supplier of automation to the Automotive Industry in the world, with this experience being diversified into General Manufacturing Industry. Comau Service provides on site support contracts to back-up the installations.
