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Tire changers and Wheel balancers


We’ve visited the Snap-on plant in Correggio, where Hofmann and John Bean tire changers and wheel balancers are created. Modern methods and strict quality controls ensure quality and prompt spare parts supply and assistance 

Massimo Condolo

The Snap-On factory, located in Correggio near Reggio Emilia, is an industrial complex where tire changers, wheel aligners, balancing machines and MOT testing stations are born. Snap-On opened in the late 90's following the acquisition of GS, which had been founded over twenty years earlier, and is responsible for assembling incoming components from suppliers, additionally serving as a logistics hub for the whole group. Subjected over the years to a number of improvements in both logistics and assembly processes, Snap-On is also home to a research and development center capable of performing stress tests with accelerated cycles. In addition to automatic and semi-automatic tire changers for cars as well as commercial and industrial vehicles (sold with Hofmann, John Bean and Boxer brands), wheel aligners, balancing machines and testing equipment are likewise produced in the Correggio factory. "Our global size", says Marco Gandolfi, Senior Product Manager, "along with our roots firmly set in Correggio, are a guarantee for all our customers. Producing our machines, such as tire changers and balancers, in Italy, where manufacturing skills are essential, represents an added value for our products".


Meticulous organization in lead times and methods

"Our production lines", explains Daniele Gradellini, Operation Manager, "are integrated with in-bound supplies and production schedules, and organized according to lean production and just-in-time principles. Many components are offloaded, twice a day, directly by our production lines. Furthermore, we have three warehouses: the "supermarket" where trolleys are loaded with components to be handled for each order, the central warehouse, which handles slow moving and bulky materials, and the spare parts warehouse. Not all components are supplied just in time, though: some precision castings, for example, must be ordered six months in advance. Hardware, on the other hand, is supplied outside normal production by an external company in charge of restoring the correct levels at each location. Along the production lines machines advance manually, according to set times and end with testing and packaging operations.


Constant upgrades and fast deliveries

Recently, following the installation of new moving production lines, parts are assembled along the main line and the workstations are more ergonomic compared to manually operated lines (for example adjusting the operating height); thus, production efficiency is higher. This new approach reduced worker movements by 50%. Each station is fed by an AGV drive automatic system, a kind of tape-guided electric micro-locomotive, which pulls the trolleys where the kits used by the operators are found. 70-80% of Snap-on’s production follows customer orders that are generally processed within one week of receipt, thanks to reduced delivery times. A few parts end up as stock, but these relate to a few mass produced models.


Strict controls on each machine

Quality controls take place both along the line, through quality gates, as well as at the end of the process, on the entire production. The quality improvement processes try to detect any defective part before the same is assembled on a machine. For loose and electronically non-controllable parts, there is a separate checklist procedure. A quality controller, whose contribution cannot be measured in terms of productivity but of quality improvement, is stationed at the end of the line.


New products

The Italian market has steadily grown over the last six years, even though a slowdown was forecasted following the MCTC-Net protocol 2 getting underway, which created a peak in orders for new testing lines. Specialists want more performance, and above all, user-friendly machines. It’s not just an economic issue (less working hours) but a need arising from the seasonal nature of the work and the use of increasingly frequent temporary or untrained staff at greater risk of error. This is the philosophy behind the entry level Hofmann 7340 and John Bean B340 wheel balancers, with their innovative, unique in their class, video touch screen control and software with smartphone-style graphics. The 7750, on the other hand, offers the perfect solutions for higher productivity. Both machines are based on a VPM measurement technique for uncompromised accuracy, based on a 512 notch encoder, which significantly reduces the errors due to shocks and vibration and, therefore, the need for adjustments. The 7750 has been designed with remarkable attention to ergonomics: the centering rings are arranged on the body of the machine, the automatic wheel lift (that quickly moves away once its task is completed) is integrated and supported by a motion carriage to reduce fatigue and speed up the placement of the wheel. The wheel guard is telescopic and a light illuminates the inner part of the rim. The balancer also provides for sixteen pockets for the clip weights and a few dedicated places for the box of adhesive weights and utensils. Looking at the John Bean catalog we cannot help but noticing the B340SPROTouch with electromechanical wheel lock that prevents any possible imbalance due to tightening. The V1200 aligner, available in Italy from the end of the year, is a three-dimensional wheel alignment device that can operate even in the confined spaces of a store. Portable slip plates make it possible to be used also by mobile operators; and to make it even more user-friendly, the machine shares the same batteries as a screw gun. Two new lifts have been included in the Hofmann catalog; the HL3500 for cars and the HL5500, specifically designed for the German market and also suitable for light commercial vehicles.


Spare parts and service

The Spare Parts warehouse has all the codes used for service activities. A courier collects spare parts twice a day. Every six months in-house stocks are checked as well as the codes positions on the shelves. In 98% of cases, Snap-on Equipment delivers spare parts within 24 hours from receiving the order.


The snap-on group

"The Snap-on group", explains Serena Franchi, Marketing Manager Europe, "has over 12 thousand employees and a $ 3.5 billion turnover. It’s among the top 50 companies listed on the New York Stock Exchange and has 95 years of history. Correggio is the European base of the group and contributes with 100 million Euro in revenue per year". Other important production sites are located in Arkansas (USA) and close to Shanghai. "In addition to tire equipment," explains Claudio Baldaccini, Sales Director Italy, "with brands such as Hofmann, John Bean and Boxer, Snap-on Equipment is active in several sectors". Its handheld diagnostic accessories, among the first on the market in the United States as well as many European countries with its Sun logo, are appreciated for the wide vehicle coverage, data reliability and error detection speed. A/C ​​refill brand Ecotechnics caters for a large range of cars, trucks and buses, earth movers and tractors, with R134 refrigerant gas or carbon dioxide. Cartec is the group’s brand of brake test benches, used in MOT inspections for two, three and four wheelers including three-wheeled scooter Ape style and quads. The split rollers, a technology normally used on heavy vehicles, can adapt to any wheel track thanks to lateral control. Motorcycles are inspected through four load cells signals; systems based on two cells can record the wrong braking values. The connections of the new RP brake test benches are now wireless. Finally, three years ago, following the takeover of Challenger Lift, the group added vehicle lifts to its portfolio of products, including models developed exclusively for the European market.

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