Quality Metalcraft Inc. (Livonia, MI) is a precision stamping and assembly plant, specializing in proto- type or low production parts for Detroit-based automotive manufacturers. Recently the company decided to use modular tooling components for its layout and inspection operations. Quality Manager Jim Bowdler and Chief CMM (coordinate measuring machine) Technician Bill Ralph contacted American Modular Tooling (AMT, Warren, MI). Their goal was to decrease expenditures while maintaining or improving the accuracy required for their clients.
Says Ralph, “I have been in the CMM world for a while, and I know how much fixturing can cost. I suggested we bring in modular fixturing so we could cut that cost down and basically, in the future, almost eliminate it.”
A modular fixture was constructed to hold the two body sides of the Ford Mustang. The lightweight framework was built of AMT Professional Grade hollows-7075 aircraft aluminum bars hard-coated, with a channeled center. They are interchangeable, with chamfered holes drilled at 40-millimeter intervals.
The modular fixture held the auto parts in body position while they were checked for size and location of holes, forms and contours, edges and gap accuracies. Ralph says, “This modular fixture gives me the opportunity to set up in body. If I have a data structure, it will set up that way.”
The fixture was not built from a drawing, but to part print. Quality Metalcraft initially began with a kit of off-the-shelf locators, clamps and adjustable elements. “It’s easy to learn, but there is so much there that you have to sort through it,” says Ralph. “Once you know what everything does, it’s like working with one of those Erector sets you had when you were a kid. It’s very, very user friendly.”
Asked if he would have done anything differently, Ralph says, “I would have spent probably two weeks at AMT’s shop. I would recommend it to anybody. You are better off sticking with the people who know what to do with it. Learn from them, it makes things a little quicker. You might learn a couple more tricks of the trade right away, which you need in my situation.”
The initial fixture took about 40 man-hours per side to build. When the Mustang job was finished, the fixture was converted for use on another project, this time for Toyota. “Then we went to the Toyota doors, the front left and right,” says Ralph. “It took me a week to build them, and I’m improving.”
Modular fixturing is now saving money at Quality Metalcraft and has been incorporated into the company’s system. With the use of modular fixturing, Ralph says that it costs about $3,000 to overhaul the fixture for each new project, while purchasing a new fixture would cost approximately $100,000. “It should last for years,” says Ralph. “What is nice about it is that after you are done, you pull out a piece of paper, pull the part and put it in a box. The next time you need it, you pull it out and put it back together.”
- American Modular Tooling (AMT),
a trade name of Paul W. Marino Gages Inc.