DNC network provides economical solution.

Shear Tool in Saginaw, MI, has been producing high quality machinery for the plastics and automotive industries for 53 years. But within the last two years the company reinvented the way it runs its horizontal boring mills. The company has added a DNC networking system, complete with a touch screen PC, to the shopfloor, making the manufacture of plastic mixers, components, dyes, prototype parts, and other equipment easier, faster, and more cost effective.

Until 1996, Shear Tool had been using a "switch box" system to run a very limited networking system. That is, it had provided a link between the CAD/CAM system and some of the company's machine tools, then used a switch box to download the part program into the machine tool's control. The rest of the machine tools had parts programs loaded into them manually or, on the newer machines with hard drives, loaded from floppy disks.

By the fall of 1996, the company had acquired three older machine tools with limited memory in their controls. Also, as the part program files had become larger, the memory in some of the other machine tools became an issue, so Shear Tool began investigating methods to alleviate the problem. Steve Dill and Mark Ryder, both group leaders at the company, initially sought bids on memory upgrades for the controls. But they soon learned upgrading was cost-prohibitive. Then one of the company's machine tool repairmen recommended a local company that he thought might be able to provide a more economical solution. On the repairman's advice, Messrs Dill and Ryder contacted Al Johnson at Richmond Machine and Engineering, Columbus, MI.

After a visit to Shear Tool, he recommended the purchase of a DNC networking system that would provide the company with a method of storing large files as well as parts programs transfer without the inconvenience or cost of upgrading each individual machine tool control. It would also eliminate another hassle. Mr Dill said that a networking system would save the shopfloor personnel from having to shout back and forth at each other regarding the transfer of the file from the CAD/CAM system in an already noisy environment.

In December 1996, Shear Tool took Mr Johnson's advice and purchased WinDNC software and a Touch Station touch screen industrial PC manufactured by Greco Systems, El Cajon, CA, to communicate to five of the company's steel-cutting large horizontal boring mills.

An easy-to-use Windows application for the transfer, storage, and editing of parts programs, WinDNC is also engineered to run several jobs concurrently (multi-tasking) and has the ability to communicate with nearly every CNC machine ever manufactured regardless of age. This was important to Shear Tool, since several of the machines scheduled to communicate to the network had older controls.

Shear Tool selected WinDNC as its networking software of choice because the company wanted to use Windows 3.1 as their operating system. (WinDNC can also be economically upgraded to Windows 95 or NT.) Also, it allowed them the capability of communicating to the machine tool controls without tying up the company's CAD/CAM system.

The company also purchased one of Greco Systems' Touch Stations. The industrialized 586-technology, color touch screen PC is built specifically to withstand harsh or dusty manufacturing environments.

Mr Johnson installed the new system to communicate to five selected machine tool controls. The tools were selected to run on the new network because of their limited memory capacities and because they are located in a somewhat remote area of the plant. The complete installation took about two weeks with no downtime.

The system is configured so that after the file is created in the CAD/CAM system, it is communicated to the company's file server. Once a new program is sent to the file server, it communicates with the Touch Station, which is loaded with the WinDNC application. The file is then stored within WinDNC until it is required by an operator on the shopfloor. At this point, the operator can either download the program from the PC or use a feature of the WinDNC called Remote Call Down. This feature allows the operator to call up the file on his control, then download the program directly into the control's memory from the Touch Station.

Estimated overall time savings is about 10 hr per week. The direct cost savings works out to about $500 a week. But the greatest benefit is improved overall machining capabilities.