Home » Plastic Injection Guide » A Shop View on Industry Change

A Shop View on Industry Change

Posted by: Mu Ju 2019-09-07 Comments Off on A Shop View on Industry Change

What one shop general manager has learned throughout the past 30 years.

I have learned so much about this industry throughout my 30-year career in the mold manufacturing trade, but most wasn’t what I learned from my apprenticeship classes, reading books or trade magazines, or going to seminars. I gleaned most of my knowledge from the journeymen moldmaker for whom I worked.

When I look back I realize how much I appreciate learning from men of great skill who through insight, experience, hard work and vision taught me to take a two-dimensional drawing and produce a three-dimensional mold. These men took the time to teach a young man everything he knows today.

They taught me the importance of doing the job right and shipping it on time. They took the time and energy required to teach me the skills necessary to set up and run machines, plan out a job and build the mold. But more importantly, they taught me values: pride in your work, loyalty to your company, integrity, helping others and a good work ethic—all values that are still with me today and ones that will be passed down to the next generation of mold builders.

Moldmakers Evolve
Through all of my training and work experience, I’ve witnessed much change over the years, which has made us better moldmakers as well as better businesspeople.

CAD/CAM has probably done more for the way we build molds than anything else. The days of painstakingly drawing out a mold design by hand on a board and tracing a part print on Mylar that was behind the paper using pencils has been replaced by computers with CAD tubes that have libraries of information to make the job easier and more automated.

Many of these moldmakers of old have gone from working on a horizontal granite plate all day to resting by a vertical one. We moved on from the tedious task of studying prints, scaling each item, using the Machinist Handbook and a calculator to generate the trigonometry needed to lay out the actions of the mold, the water, the ejection and EDM locations—all of which were physically scribed on the steel with a height gage. This could take a seasoned moldmaker anywhere from one to two weeks.

Now we have 3-D solid modeling that generates the programs to perform the machining in a fraction of the time. The moldmaker has become a manager who plans out the mold’s path through the shop with tracking software on a tube of his own.

Every moldmaker worth his wage had 20 or more high-precision, hand-made tools that had taken thousands of hours to build on his own time, such as V-blocks, special measuring tools, angle plates, and a variety of fixturing devices. Now all of these tools— many of which had been passed down from one generation of moldmakers to the next—are obsolete and still sitting in their beautiful oak Gersner prisons, thanks to CMM, three and five-axis cnc machining centers and a variety of other new technologies our industry uses today.

Gone are the days of the wooden model, the day-long machine setups that required hand calculation of the geometry, figuring out angles then clamping the workpiece with C-clamps, bolts and even chaining the workpiece down for safety. Now that we have 5-axis machines, blocks can be set up simply square, and many times magnets are used to hold it in position.

All our cutters were high speed and checked with a set of micrometers, and carbide was nearly nonexistent. Many of the machines—although they had motors that drove the ball screws—were hand dialed to final dimensions with large 20-inch diameter cranks turned with your hands and feet. High-speed machining was 100 ipm. Today it’s 2,500 ipm with CNC linear drive machines, lasers that calibrate the tools and hand cranks for quick tool pick-ups no bigger than a 50-cent piece.

Electrodes for the EDM process where made by hand. You would make a two-hour setup, then grind the black carbon on a small surface grinder, returning home covered in so much black dust people wondered where the coal mine was in town. Today these electrodes are quickly mounted in pallets and placed in machines with vacuums and closed environments by robots that run 24/7 without human intervention.

Running machines 30 years ago was a lot of manual/physical labor. You hand cranked every machine. For instance, when you drilled a water line 40 inches deep by hand you would turn the big wheel around—one turn was 1 inch. Then you drilled a 1/4-inch and backed it out. So a 20-inch deep hole would be turning the crank hundreds of times then turning the block around and repeating the same process, all the while praying they met in the middle. We busted our humps to get one hole every four hours versus a modern gundrill that can drill a 40-inch deep hole in 10 minutes!

Bench hands were artisans who had to actually hand engrave all the detail into the mold steel with chisels and manual tools. Now every bit of detail is cut or EDM’d.

Thirty years ago, we had to pick up all of these skills, understand all the math and learn the art of being a journeyman moldmaker while gaining enough experience to lead jobs on our own—which often took 10 years. Today, it takes three to four years, since so much of the mold build process comes from software programs, new hardware, high-tech machinery and purchasing mold components from outside sources.

Onward and Upward
The past 30 years have been great and have shown us the many advantages to the way we used to do things in this trade. The new reality is we’ve become faster, better and far more competitive in this global environment in which we are forced to survive today.

Link to this article:A Shop View on Industry Change

Reprint Statement: If there are no special instructions, all articles on this site are original. Please indicate the source for reprinting:Mold Wiki,Thanks!^^