CNC Coilers are Here to Stay

Articles, Springs Magazine

I would have to say that nothing in history, aside from the printing press, has had or will have the historical impact of the computer. Twenty years ago, when computers were refined to the point of individual ownership, the race was on to see how many things could be connected to them. Spring coilers were one of those items.

In a past issue, I discussed the need for training and how that relationship works best when the teacher has a student who wants to learn. As we get older (you know, we mature adults), we tend to want a comfort zone, not rocking the boat or rushing headlong into new approaches. Well, nothing rocked the spring world like computer numerically controlled (CNC) coiling machines. I was a coiler on a mechanical machine when my company bought its first CNC spring maker. It arrived as a strange visitor from a faraway land. People wanted to run up and touch it, and then run away. It was different: It sat up instead of out, and it had a box with buttons that glowed with a bright green light. You either loved it … or hated it. I loved it. I thought it was fantastic and still do. But in an era where people feared losing their jobs to computers, the CNC coiler was not so liked by many.

Over the years, CNCs have found their place in spring making when complex geometries are needed. They have the ability to create a finished spring that has multiple hooks, bends, radii, angular positions, and on and on. The introduction of CNCs simplified spring coiling in many respects. At the same time, it required some new disciplines from a spring maker. One of those was creativity. Mechanical coilers were limited in wire feed length and diameters. Cams and rotating gears could only provide so much flexibility. A spring maker could tell you quickly whether his/her machine could do a particular part, given the wire size, diameter, coils and free length. Most mechanical coilers had a list (on an engraved machine plate) of what their limits were concerning wire size, wire feed, diameter limit and so on; it was fairly cut and dried. Torsion springs with multiple bends on the legs required multiple secondary operations or specialized, custom machinery.

CNC coilers have eliminated a lot of the limits for complex springs. With multiple slides, and various arbors, support tools, radius pins and cutters, these machines can make some of the most demanding spring shapes, complete. And although CNC coilers also have their spatial limits, they have decreased the time needed to produce springs with multiple bends and forms.

Mistakenly, much of the capability is lauded upon the computer and not the operator. However, a CNC coiler is really only as good as the “nut” holding the handle. The operator visualizes what tools go on what slide, at what time they are to come in, how much dwell against a certain support tool, what feed to create the proper coil position, and which probe to set for monitoring a hook or leg angle. To conceptualize multiple tasks takes a good heaping of imagination and perseverance. CNC programming is not for those who want the standard approach. Even though all CNCs have standard ways of making a common spring of a given type, they are an open slate for a new double torsion spring with nine total bends. A huge misconception concerning CNC coilers is that they set themselves up and the computer does all the work. However, the computer simply goes through the motions; it’s the human who makes the intellectual decisions on the creation and choice of all tooling, and spatial considerations. Operating a CNC requires focus and a no-nonsense devotion. It also requires those same tools be put back in the same place, the same way, every time.

I’m absolutely sure that hand coiling was seen as a dying art as soon as the first “motor” was put on a spring coiler to make a spring. We still hand coil to this day. I’ve heard discussions for so many years on how CNC machines eliminate jobs, just because they have a dumb box hooked to them. Well, that dumb box still needs a motivated human to operate correctly. Let’s not forget that computers, with all their problems, have created a new job market for millions across the globe. I even had one old-timer, who loathed CNC machines, glow with paternal pride that his son was going to school for computer science.

Yes, computers are here to stay and so are all the machines they command. I, personally, believe there is room for all types of machines in the spring industry, including the old faithful mechanical compression spring makers. But let’s be honest: The customer drives the business, and as the parts we make diversify, we must find better and faster ways to produce them. CNC has filled that need and has done it with impressive results. If you’re doing nothing more than cutting straight sections to length, the CNC is not your bag of tricks; a simpler, cheaper device will suffice. But, if you have complex-geometry cold wound helical springs with low or high volume, CNC has created a way to challenge us operators to make it happen for you.

It’s not unusual for those in equipment sales to announce a new or improved function for CNC machines. It’s all about more product with less cost.

But as much as we’d like to think the machine can outsmart us, it can’t. The same creative mind force that conceptualized the machine is needed to successfully adapt it. A computer is a machine waiting for instructions. Once the instructions are given in the proper sequence and the tooling is in place to push, pull, tug, stamp or smash a piece of wire, the finished product pops off this mass of whirling metal to fit and function in the customer’s application. And as much as we’d like to think we could leisurely relax while the machine magically creates its own instructions, we can’t. The whole process is still overseen and driven by a human operator and the one ingredient that can’t be ignored: creativity!

By: Randy DeFord, Engineering Manager Mid-West Spring & Stamping