Like Swiss clockwork
Fastems automation used to create sophisticated products
Knoepfel AG is a Swiss family business employing about 50 people. One of the areas it specializes in is the highly automated production of large numbers of precision components. For over a decade now, a Fastems high-availability Multi-Level System (MLS) has played a key role in this regard as part of a flexible manufacturing system (FMS).
“When we moved into our current production facility at Gaismoos in 1991, many people outside of the company were initially amazed to learn that we had fitted our production buildings with air-conditioning”, recalls Urs Knoepfel, a member of the Supervisory Board of Knoepfel AG, headquarters in the village of Walzenhausen close to Lake Constance.
What was originally intended to benefit the workforce subsequently turned out to be a very far-sighted investment.
“Without the recently modernized air-conditioning system we wouldn’t be able to manufacture our components with the high level of precision and quality that is necessary. This is because the AC incorporates a modern heat recovery system and ensures a constant room temperature in the production area”, stresses Sales Manager, Roman Sgier.
From precision component to the testing centre
Currently, Knoepfel AG has three main areas of business: precision components manufacturing, rotary manufacturing, and a measurement and testing center. Roman Sgier provides more details: “Our rotary manufacturing operation consists of six machining centers, which we use to manufacture components ranging in diameter from 30 mm to 680 mm. These can be up to 2,000 mm long and our workpieces can weigh up to 600 kg. For instance, in our CNC high-precision hard turning cells we manufacture components to tolerances of less than 5μm. Our measurement and testing center, located in segregated rooms, meets the most exacting testing requirements through the use of 3D coordinate measuring machines. It incorporates a measuring machine with a level of testing accuracy which exceeds 1μm and into which 13 pallets are automatically fed for automated measurement. It’s the only one of its kind in Switzerland. Finally, the range of services is rounded off by an automated precision components manufacturing facility. This enables us to undertake the fully automated, integrated cubic CNC machining of workpieces weighing up to 2,500 kg.”
A wide range of products for the industrial, mobility and aerospace sectors
The range of products produced by Knoepfel is extensive. To mention a few examples, the company’s portfolio includes components for injection tools used in plastics processing, the manufacturing of PET blanks and key components for helicopters and the space industry (e.g. satellites) as well as high-precision bearing housings for marine diesel motors. Small and medium-sized batches of 20 to 100 items per year are primarily produced, with larger components usually being produced in small batches.
An important step into the future
Ultimate precision is the be-all and end-all at Knoepfel AG, albeit subject to profitability constraints, as Urs Knoepfel stresses. “Switzerland is a high-income country. That’s why we were very quick to invest in automation. In 1997 for example, we already purchased machinery incorporating pallet pools. In order to get ahead of the field in terms of complexity and levels of precision – and consequently to be able to produce parts which other businesses can’t manufacture – we’ve had to maintain this forward-looking approach. That’s why in 2008 we decided to invest in a Fastems Multi-Level System which is designed for 3 horizontal MCs. For us this was a crucial step into the future because this system enabled us to manufacture the high-precision components which our customers expect from us in a highly automated and very flexible manner – and on a just-in-time basis.”
Expanded with up to three MCs to meet demand
Fastems’ MLS-MD (Medium Duty) was designed from the outset to be supplemented with machining centers. It has a load capacity of 2.5 tonnes per pallet, and with a length of 40 metres and a height of almost 6 metres it provides space for a total of 40 machine pallets. The system also incorporates two loading and unloading stations for the transfer of parts.
Initially a horizontal Hüller Hille NBH 290 machining center with a high-precision package was incorporated into the system. As Urs Knoepfel says, “We gained initial experience of using this solution, and after about two years we supplemented it with a further Hüller Hille unit, an NBH 260”. Then in 2014 a third machine of the same model was added.
20 different major components permanently in the system
“We generally always use this FMS to produce roughly 20 different components, usually using two settings, so we need a total of 40 pallets. However, although we have many recurring products here, the units are designed for the production of more than 100 components a year,” Roman Sgier explains.
Accordingly, the tool storages of each of the two NBH 260 units are fitted with 400 tools. However, a special feature is the capacity of the NBH 290, which has a total of 800 HSK-100 tools. Urs Knoepfel comments as follows: “We’ve used a diploma project to specifically develop an enhancement which enables 400 additional tools to be used. The large number of tool spaces for all the machines is required for us to also be able to undertake the highly complex and high-precision machining of the workpieces in a fully automated manner, e.g. at night-time.”
Fully automated production for up to 40 hours
On the other had, manned production is undertaken exclusively with single-shift operations. Here, one employee is responsible for each machine. There are also two employees working at the loading and unloading stations. “Our aim is always to arrange for all the machines to operate on a fully automated basis until the start of the next morning’s shift. Of course this always depends on how the respective orders are arranged and on the components that are to be produced, not to mention the machining times that are involved”, says Roman Sgier.
“About 50% of the time we are machining cast iron and cast aluminium components as well as a wide variety of grades of steel and aluminium. This means the machining times vary greatly, ranging from an average of one hour to 10 hours for each machine pallet. If we’ve got an ideal supply of MLS work we sometimes achieve up to 40 hours of continuous, fully automated production over the course of a weekend, and in principle the NBH 290 always operates continuously”, says Sgier. This means that the Fastems solution enables up to 5,000 hours of spindle operation for each machine every year.
Successful partnership is being continued
“The FMS is a key element of our automated manufacturing operations, and it offers the advantage of an extremely high level of availability. In addition, since we carry out preventive maintenance at least twice a year, the system has never let us down”,
is how Urs Knoepfel sums up the situation. He has no doubt that the successful cooperation with Fastems will continue based on the extremely positive experience to date.
In fact, Knoepfel AG’s plans include expanding production with additional machines. The intention is to automate the new investments through the use of a robot cell for handling heavy workpieces in conjunction with a Flexible Pallet Container (FPC). Urs Knoepfel adds: “We’re also planning to supplement our current range of services by undertaking modular assembly. Currently, we’re creating the necessary space for this within our production operations by building a new warehouse on our company site.”