Why CNC
Spring Coilers?
Though it may seem too expensive to invest in modern equipment, not upgrading may actually cost you more in the long run.
By Chris Dix, RK Trading Co.

If you had a choice, which machine would you choose to meet your spring production requirements?
(A) A machine that requires:
1. An operator with a highly developed set of skills, most often learned through experience.
2. An operator who “sees” or intuits the effect cam shape, size and position will have on the machine’s actions.
3. A machine that has few, if any, pre-sets to determine proper tool array or setting position.
4. A machine that is, in most cases, relatively limited in production rates.
5. A machine that demands incrementally longer and more difficult setups to produce complex shapes in springs.
or (B) A machine that:
1. Allows even a novice to make simple parts within a few hours.
2. Eliminates the need for complex cams.
3. Has pre-sets and functions that eliminate the need for specially shaped tooling while offering high repeatability in setting procedures.
4. Enhances production rates with no loss of accuracy.
5. Greatly reduces setup times on both simple and complex parts.
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Obviously, we are talking about some of the differences between CNC spring coilers (as designed primarily for compression springs) and the old-fashioned mechanical coilers. As King Mongkut says in The King and I, “Etcetera, etcetera, etcetera.” The list of advantages for CNC machines goes on and on.

Why not CNC?
Equally obvious are the reasons more of these machines are not in use in North America today. Simply put: cost. Ironically, the transfer of spring markets in North America to offshore producers (especially China) has caused a great increase in the need for production machinery in these new markets. In virtually every instance, this need is being met by the purchase of CNC coilers. Ergo, we find ourselves faced with a stagnant market and competitors, both here and abroad, who are armed (in many cases) with better, more efficient tools. Add to this today’s increasingly demanding customers: “Give me better quality, faster deliveries, match your schedule to meet my needs – and by the way, lower your prices.” Welcome to today’s spring industry!
We live in an age where cell phones, Wi-Fi (wireless networking), e-mails, EDI (electronic data interchange), digital image transfer, etc. are part of our daily business regimen, yet we rely on production equipment whose basic technology was first put into widespread use over 80 years ago! I would suggest that, as the conduct of our business on a daily basis has changed, so too should the way we view our ways of producing parts. The old methods used to calculate cost vs. benefit ratios do not adequately reflect the demands of this new marketplace. Nor do they (the formulae) consider the consequences, both favorable and unfavorable, of a failure to modernize. But, again, the advantages of this modern equipment do not come without cost.

Add up the Benefits
It’s difficult to discuss precise cost vs. benefit because of the wide differences in price, function and features in the machines available today. For example, a new three-axis CNC in the 2mm size range could probably be purchased for around $55,000, plus or minus. An 11-axis machine in the size range may cost over $100,000. Typically, as the number of axes increases, so does the versatility, ease and repeatability of setup but so too does the cost. However, in virtually every instance, the following facts hold true:
• Setup times will be decreased by a minimum of 50%.
• Special tooling, such as custom-ground arbors (mandrels), pitch tools and coiling points, is almost universally eliminated. The savings in labor, coupled with the elimination of dedicated tooling, is quite significant.
• Repeat setup times will be decreased by the same factor.
• Production rates will be higher. In some cases we at RK have seen, the increase has been well over 200%.