Reposted from sme.org/MEmagazine…. originally on January 6, 2016
Toolcraft began life in the mid-1960s and Steve started working for the company in 1974. “In those days I mainly worked on rebuilding pre-NC machine tools. We’d tear them down and completely refurbish them. We would also make modifications for the customer and build new gages and fixtures. Eventually, the fixtures and gages became the bigger part of Toolcraft’s business,” Meyer said.
In 2009, Steve and his brother, Bruce, purchased the company from the founder’s family. “We were very fortunate that the employee with the least amount of service had been there 21 years,” said Steve. As close and loyal as Toolcraft’s employees are, however, they were more than a bit apprehensive when Steve and John started moving in a new direction. According to Steve: “We had always been a onesy-twosy tool and die shop, then we began repairing tooling for Tuthill pumps.”
Tuthill was founded in 1892 and started its pump division in 1927. Today, Tuthill Transfer Systems (TTS; Fort Wayne, IN) makes the Fill-Rite and Sotera brands of pumps and meters. Fill-Rite “The Little Red Pump” is TTS’ largest division with its fuel transfer pumps used in agriculture and industries worldwide. TTS tries to use local suppliers whenever possible, and on a visit to Toolcraft’s facility, discovered a well-organized, quality-conscious shop. They then asked Steve and John if they were interested in producing parts for the Fill-Rite pumps.
“We had never done this kind of production work before, and I was reluctant at first, but then I realized that this was an opportunity to do something Bruce, John, and I had been talking about for many years: adding CNC production capabilities,” said Steve Meyer. “I had to assure the employees that we aren’t abandoning our tool and die business but adding a new CNC business. We actually own another building that will house our CNC division, so it won’t impact the tool and die operations.”
As Steve and John considered the challenge of producing hundreds, rather than one or two parts per order, it became clear that there was more to this than simply buying a new CNC machine. While considering various options, Toolcraft received a phone call from Dave Werblo with the Indiana office of Gosiger Inc. Although they already had a proposal from another source, Steve and John invited Dave to come in the next day to discuss their situation.
“Dave told us all he wanted us to do was to visit the Gosiger headquarters in Dayton to see what they were capable of. So we made the trip. Not only were we impressed with the people and facilities, but Dave had previously given the Gosiger staff one of the parts and they had already come up with a detailed proposal that gave us everything we asked for, and more,” said Steve.
The part that Tuthill asked Toolcraft to make is a flanged bung that attaches the pump to a tank mounted on a farmer’s pickup truck or located elsewhere on the farm property. The part has a flat surface, is secured by four bolts, and has ID and OD threads. Toolcraft would receive a raw casting and perform facing, drilling, and thread machining on each workpiece.
“One thing that bothered us was how the machine operator would be able to load and unload so many parts during a shift. It would be tiring and repetitious work that we wouldn’t want to do ourselves, so we couldn’t ask an employee to do it either. We were also concerned with our ability to keep up production if the employee was absent. Gosiger’s answer was to include a robot with the CNC cell. Adding the robot didn’t cost anyone his job, in fact we added 1.5 people to program and manage the system,” said Meyer.
The solution Gosiger Automation devised uses two Okuma Genos L-300MW two-axis lathes serviced by a Fanuc M-10iA six-axis industrial robot. Because the lathes are equipped with subspindles and redundant tooling, there is little wait time between operations. The system also includes Gosiger’s standard Modular Drawer Cell that enables users to load raw workpieces and unload finished parts weighing up to 20 lb (9 kg) in a heavy-duty drawer system. Each drawer of the cabinet can hold part payloads of up to 400 lb (181.4 kg).
For this application, Gosiger Automation mounted the robot, robot control, and inbound/outbound four-drawer system on a common frame, positioned in between and centered on the two lathes, with the drawer system on one side for staging raw and finished parts. The robot employs two mechanical, three-jaw grippers for loading and unloading workpieces. This tooling enables the robot to handle two parts at a time for more efficient machine unloading and reloading. This configuration also has the advantage of easy and inexpensive reprogramming and retooling if part dimensions change, or when it’s necessary to adapt the system to new parts orders.
The operator begins the process by loading the castings centerline vertical into the system with the first surface to be machined facing up. In operation, the robot pulls a drawer into the cell, picks a raw casting from the drawer, unloads a finished part from the main spindle and loads the raw casting into the subspindle at the same time. While the subspindle is running, the robot places the finished part it took out of the main spindle into the drawer.
When the subspindle has run its cycle, the subspindle places the semifinished part into the main spindle to finish it. The robot returns the finished part to the drawer and the process repeats. When all parts in a drawer are completed, the robot pushes the drawer back into the cabinet and pulls another drawer full of castings into the cell for continuous parts processing from drawer to drawer. Because each machine produces a finished part, if one lathe is being serviced the other continues to run production.
As part of Toolcraft’s quality control, after a set number of parts are processed, the system automatically discharges a part into a chute for inspection and lights a beacon to alert the operator while automation continues. If, after a prescribed period of time, the operator has not responded, the system stops running and sounds an audible alarm.
When unloading finished parts from the drawer cell, the operator blows off any debris and visually inspects the parts before sending them on for delivery. A number of safeguards, including perimeter guarding with an interlocked access point are built into the system to protect personnel from coming in contact with the robot arm.
“Our customer, Tuthill, is very happy with the parts we’re producing with this new system and with the flexibility that allows us to meet their JIT delivery requirements as order volumes fluctuate,” said Meyer.