The need for feed

The bottom line for any barfeed is to help automate the delivery of stock for making precision parts. In recent years, barfeed manufacturers have concentrated on improving speed, delivery and bar stock capacity, a period of evolution that is now leading some vendors to rationalise their product ranges, it appears. FMB, for instance, is in the process of reducing the number of models in its product programme, yet extending the range of bar diameters that each can accommodate. UK agent Star GB cites a good example. The FMB Minimag 20, which is a step up from the 18 mm diameter capacity model, has been fitted with a 22 mm pusher for feeding bar of 20 mm diameter, without bar end preparation. Minimag 20 can handle bar down to 2 mm in diameter and lengths up to 3.2 or 4.2 m. Features include micro-processor control, central adjustment of all essential functions, easy retrofit integration, rapid bar change, low noise, minimum vibration, the ability to feed profile material and a small footprint. "Despite the strength of the euro, FMB barfeed sales are still strong in the UK, as automated manufacture is crucial when times are difficult, in order to minimise labour costs," says Bob Hunt, managing director of Star GB. With UK machine shops increasingly concentrating production on more complex value-added contracts, investment in more capable CNC machine tools often follows. Operating such machines without effective handling equipment is, however, a false economy, argues Giampaolo Morandi, sales and marketing director at barfeed specialist Iemca, which is represented in the UK by Kitagawa. BENEFITS SQUANDERED Machines only provide ROI (return on investment) when they are cutting metal and hence it is no surprise that machine tool builders assign the majority of their resources to maximising the percentage of cutting time within the total machining cycle. The demand for greater productivity is reflected in ongoing developments to minimise tool indexing and rapid feed times, as well as to increase spindle speeds and metal removal rates. Yet some of these hard won benefits are wasted if component loading and unloading times are not minimised, too, or if the barfeed is incapable of allowing the machine to operate at its full capability. "Through the use of low inertia components, we are able to ensure precise synchronisation with headstocks actuated by linear motors, which can operate at more than 2 G," says Mr Morandi. "We are also in the process of developing new units that will be capable of supporting up to 5 G." Further developments at Iemca focus on reducing operator input and maximising unattended running times through increased magazine capacities and the use of longer bars. The philosophy that underpins Iemca's latest generation barfeeds has also been applied to the company's newest workholding development, the Automata, an integrated gantry system that boosts the productivity of CNC manufacturing equipment such as lathes, grinders, rolling equipment and machining centres. Units offer a standard load/unload cycle time of just seven seconds, and will feed, unload and store bulk components weighing up to 5 kg automatically, with positional repeatability of ±0.1 mm. 'ONLY ONE' CLAIM Tornos claims to be the only manufacturer producing barfeeds for both its single spindle and multi-spindle machines. The new SBF532 and SBF216 have been developed for single spindle Deco and Sigma machines, and are now equipped as standard with four channel sizes and pushrods to cover bar ranges from 5 to 32 mm or from 2 to 16 mm. The channel inserts are prismatic in section, with each side having a different channel size, so when changing capacity there is no need to remove and replace the inserts – simply turn the insert round such that the side facing upwards corresponds to the channel size required. The use of a multiple capacity guide channel, and the choice of four interchangeable push rod sizes operated by a simple latching mechanism, curb unnecessary handling, and reduce set-up and changeover times. Similarly, the Tornos MSF barfeeds for multi-spindle machines incorporate the integrated features seen on the single spindle SBF532 and SBF216. The MSF range now includes the 522/6, 522/8 and 632/6 models. The designation 522/6, for example, represents a 5 to 22 mm diameter range for a six-spindle machine. UK manufacturer Hydrafeed has also been busy adding to its growing portfolio of products. The company now offers a range of short magazine barfeeds, as well as full length models, coupled with additional automation products to complement any CNC turning centre, "Hydrafeed's Multiservo short magazine barfeed is able to minimise feeding cycles with features that can effectively remove the barfeed cycle time, in some instances," says the company's operations director, Martyn Page. "Bars to be loaded can be measured and prepared while the machine is working on a pre-loaded bar, thereby reducing dead time on the lathe to virtually zero. The benefits of this application are most apparent when the Multiservo is fitted to sliding- head type machines or twin-spindle fixed- head machines. The Hydrafeed range continues to expand, with the Autofeed long magazine barfeed being available in up to 65 mm bar capacity by the end of the year, while a new short magazine barfeed introduced earlier in 2009 (MV65) allows users to get a constant display of the remaining bar length. Mr Page also says that "the increase in sales of the Hydrafeed X-Tract shaft un-loader is proof that customers are seeking to automate manufacturing processes wherever possible". The X-Tract has highlighted Hydrafeed's ability to "soft handle" parts, removing labour from high specification turning centres. The product has also been improved to offer quicker unloading times through the addition of rotary encoders and component parameter storage capability, says the system's maker, which adds that one has recently been installed at a car component manufacturer in Europe.n One of the more recent introductions to the LNS barfeed range is Move S2, which is targeted at subcontract shops where frequent application changes in day-to-day operation can result in substantial changeover time. LNS says Move 32 will be popular where customers wish to have a small footprint and need to run bar lengths longer than the lathe headstock. Move S2 is an intermediate length barfeed with capacity from 8 to 8 0mm diameter, and lengths of 0.7 to 2 m (dependant on lathe headstock) with floor-loading capability to aid compliance with lifting legislation. No bar support systems are required, and the system is hydrodynamic to eliminate noise and vibration. All LNS Servo products feeding to position have sub-spindle mode that can save 5-10 seconds of production time per component. Recent additions to the QLS (Quick Load Servo) range are the QLS 65 and QLS 80, and as with all QLS barfeeds they can be transformed easily for special applications such as billet loading, shaft loading and back stop working. Box item System aims to slash changeover times One of the more recent introductions to the LNS barfeed range is Move S2, which is targeted at sub-contract shops where frequent application changes in day-to-day operation can result in substantial changeover time. LNS says Move 32 will be popular where customers wish to have a small footprint and need to run bar lengths longer than the lathe headstock. Move S2 is an intermediate length barfeed, having capacity of from 8 to 80 mm diameter, and lengths of 0.7 to 2 m (depending on lathe headstock), with floor-loading capability to aid compliance with lifting legislation. No bar support systems are required, and the system is hydrodynamic to eliminate noise and vibration. All LNS Servo products having 'feed to position' have a sub-spindle mode that can save 5-10 seconds of production time per component, it is claimed. Recent additions to the QLS (Quick Load Servo) range are the QLS 65 and QLS 80, and as with all QLS barfeeds, they can be transformed easily for special applications such as billet loading, shaft loading and back stop working. LNS is presently planning new products for launch at EMO Milano, October. Article first published in Machinery, April 2009