Historically, we have furnished controls for mechanical-clutch presses rated at 20 to 60 tons. We are discovering a whole new market in low-tonnage mechanical presses used in wire forming and assembly.
We recently received an inquiry from a manufacturer looking for help with their presses.
They had in service a number of 5-ton, bench-top, mechanical-clutch presses. Their controls were failing. The machines are approximately 30 years old and have been in service at this facility since new, forming thin wire. The tonnage required was just a small percentage of the rated 5 tons, so mechanically the machines ran fine. The problem was that the controls would just quit working.
The company had contacted the presses’ original manufacturer and was informed that the machines were obsolete; no service or replacement components were offered.
When this manufacturer contacted us, we requested and received one of their non-performing control boxes. It turned out to be the size of a shoe box, including a disconnect and a starter. The inside of the control was reminiscent of a 1960s transistor radio: a rat’s nest of wires stuffed into a small enclosure.
The customer had requested a proposal to fit our control circuitry inside the same form factor. It was apparent that this wouldn’t work, since our circuit board was bigger than the original box. Our control, with similar functionality, was going to measure at least 16” x 14”.
Also, our panel builder told us that in an enclosure that small the control wouldn’t meet “finger safe” requirements, as the high-voltage connections were too close to the low-voltage connections.
So we proposed an entirely new enclosure that mounted on the machine and was pretty much the same size as the press. They sent us a press and we installed the control to test it out. It looked a little strange but it worked fine. This press went back to the manufacturer, where it was put into service and performed flawlessly for six months. Then the customer ordered 10 more.