igus helps automate German red worm factory | Automation.com

igus helps automate German red worm factory

igus helps automate German red worm factory

August 23, 2018 - In a large warehouse in Germany, fully-automated machines pick up, put down, transport, stack, drill, and spray water around the clock. This company is using igus components almost exclusively to automate labor-intensive processes in the breeding and growing giant red worms, with the goal of expanding its automated units to support other small businesses who are searching for robotic solutions.

Martin Langhoff’s Duren-based business, SUPERWURM, uses self-made robots and automated guided vehicles (AGVs) that include igus bearings, energy chains, linear guides, and stepper motors to breed the worms, called dendrobena, which are used by fishermen, as a natural fertilizer for gardens and greenhouses, and as food for animals.

The wear-resistant features of the igus parts have been critical for Langhoff in the development of his business. He started a new business venture, RobCoTec, to market his automated products. “You can make sure the machines operate reliably and for a long time for the customer,’’ Langhoff said. “We also appreciate igus’ fast and uncomplicated service. You cannot find that everywhere else.”


Where do earthworms come from?

A youngster’s innocent questions nearly 20 years ago fueled the rise of Langhoff’s unique enterprise. When Langhoff’s son asked “Daddy, how do earthworms multiply?”, he turned to a source that was just beginning its infancy: the internet. The boy’s query sparked Langhoff to research and find an answer to his question. He also decided to launch a family run business dedicated to breeding the giant redworm.

Langhoff came across igus products while looking for components for his first self-built machine. Feeding and watering processes needed to be partially automated, and parts needed to function reliably in dirt, soil, and moisture. Langhoff designed his first unit to work around the clock.

Additionally, the products needed to function without lubrication so that the worms and soil remained uncontaminated. Langhoff selected drylin quad block carriages, which have solid plastic bearings and slide along two parallel shafts. He also used igus’ E4 e-chains. Both products have been used in SUPERWURM’s products for a decade – without maintenance – and spurred a business that has grown.

SUPERWURM’s warehouse is stacked with containers that consist of soil and worms. The containers are driven with a pallet truck from the warehouse to Langhoff’s first feeding and watering machine. The machine takes two units each time with a compressed air gripper and advances them to the next station, where they are sprayed with water and sprinkled with food. The drylin carriages serve as bearing points for the movable gripper elements.

Soil and moisture contaminate bearing points in the machine. Since the sliding elements of the linear guides are made of plastic with incorporated solid lubricants and thus require no additional lubrication, no lubricants reach the ground or the worms. Also, dirt cannot adhere to grease or oil on the self-lubricating parts. Much like a snow plow, foreign bodies are forced out of the way due to the contact surface between the plastic sliding element and the shaft on igus’ drylin parts.

Langhoff developed completely new machines to fully automate the feeding and watering process. These include two robots, a conveyor belt and an automated guided vehicle (AGV). The monotonous feeding and watering steps no longer need to be done by a person full-time so that they can focus on more demanding tasks. "With the new plant, feeding and watering can be carried out around the clock, even when there is a shortage of staff. In addition, errors are reduced to a minimum,” Langhoff said.

The AGV fetches the earth and worm-filled containers in batches from the warehouse to the new feeding and watering plant. For it, two parallel synchronously driven drylin ZLW toothed belt axes including gantry center-drive are installed in the AGV, which pull the container stack onto a trolley in the transport vehicle. The toothed belt axes include stepper motors, which can pull containers weighing about 265 pounds.

To move the toothed belt axes, the cables are guided with the aid of an E6 e-chain. Thus, they are protected from external influences, such as crushing. When the containers are completely retracted into the AGV, a barrier closes via an igus stepper motor (size NEMA23) to provide additional safety during transport.

Arriving at the new feeding and watering system, the AGV drives the containers to the first robot, which takes them one after the other from the trolley stack and places them onto an assembly line. At that stage, the robot works with an intelligent gripper, which detects the position of the container, corrects and raises it only when a secure grip is guaranteed

Shafts are mounted with igubal ESTM pillow blocks for opening and closing the gripper. The shafts withstand high radial loads.

In order to guide the cables safely during the fast movements of the robot and to ensure long-lasting cables, an energy chain of the E4 series is used. In addition, igus stepper motors (size NEMA23) with gearbox are used so that the gripper can shift the containers onto the assembly line.

On the assembly line, the containers are then automatically watered and food is scattered on the soil. At the other end of the assembly line, a second robot lifts the watered and fed containers off the assembly line and onto a trolley, which the AGV picks up and returns to the warehouse.

If the AGV's battery is empty, the vehicle automatically drives to the charging station and is ready for use within 30 minutes.

SUPERWURM offers a special bucket to keep the worms. Previously, large air holes had to be drilled in each bucket, which were glued with custom plastic sieves. The processing of the buckets and gluing the sieves was inefficient and costly. The self-adhesive sieves alone cost more than $2,800 a year. "Drilling the buckets and gluing the sieves were always a very annoying job for us. Nobody would like it," Langhoff said.

He designed a process in which 40 buckets can be clamped simultaneously. "Now it only takes 10 minutes to set up the buckets in the machine," Langhoff said. A power tool is moved by a drylin gantry and automatically drills the ventilation holes into the buckets. The shafts of the gantry are supported by igubal KSTM pillow block bearings so that they can be synchronized in parallel. Sieves for the holes are no longer needed since the power tool now drills the company logo into the buckets with tiny holes.

Langhoff said he encountered some difficulties in constructing the bucket drill. For the gantry, he uses drylin toothed belt axes with stepper motors. Initiators and axes holders were selected for the application to match the structural profiles. The stepper motor for the vertical axis was too weak and could not move the power tool as desired.

He solved the problem was solved with the installation of a larger motor. The Langhoffs also use the E4 type series e-chain for this machine, which enables large strokes. With their design, these energy supply chains are intended for protecting the cables during movements of the gantry. When drilling the ventilation holes many fine plastic particles are produced. The dirt-resistant igus products are suited for use around swarf.

The Langhoffs plan to market their automation solutions and have founded RobCoTec to build its customer base. Langhoff plans to use igus’ wear-resistant and maintenance-free in all of his automated units.

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