Multiple Spindles, Multiple Choices

The last recession changed how shops look at their capital equipment and manufacturing personnel. Simply put, the easy parts are gone, requiring some companies with old-style equipment to sell the parts at cost, just to keep their doors open. This is not a sustainable business plan.

More complex parts need more sophisticated equipment, which in turn, requires a higher percentage of available dollars for investments in capital equipment to offset the increased labor costs. Companies that have the courage and wherewithal to invest in such competitive technology will prosper.

The price of manufacturing solutions is getting more important since cash has become very dear to manufacturers. Most have become much more cash conscious and cautious in the aftermath of the financial crises we all went through.

What is the lesson to be learned from the recession? I believe it is that in a competitive market, the most efficient solution in all aspects will win over the most elegant solution. And the meaning of this for multi-spindle screw machines is that if a cam-actuated multi with CNC slides can do the job, why invest in a full CNC multi? The only thing you gain is increased pricing, increased cycle time and decreased uptime because of the controls. This is where we see the real changes in multi-spindle screw machine technology.

Shops need a change in perception. With advances in mechanical technology, running 50-year-old screw machines, which can be eclipsed by more current cam-actuated multi-spindles, may not be the best idea. A shop might choose to invest in a full CNC multi-spindle that can do work it never dreamed of on a multi-spindle.

I see an upsurge of interest in multi-spindle technology in the form of cam-actuated machines equipped with CNC compound slides, endworking tools and other accessories applied on selected stations where they are needed for a tolerance or surface finish requirements. Multi-spindle shops have choices today. I can say this without bias because our company manufactures cam machines with optional CNC stations and full CNC on six- and eight-spindle machines.

Here is an example. A customer made a very precise hydraulic component on a rotary transfer machine. The part ran inconsistently because of several detailed features, specifically runout and concentricity.

Then the customer bought a CNC multi to make the part. Cycle time increased, but the more good parts were in the bucket and at a much better quality than before with the transfer machine. Now this customer runs the same part, which everyone believed to be a full CNC multi part, on a cam machine with CNC applied only on selected stations (usually the finishing stations).

He can do single pointing quick tool change through form inserts, and his uptime is significantly better. The cycle time is also back—if not faster—than on a rotary transfer machine, and the quality is as consistent as it was on the CNC. Each level of technology has its application sweet spot, and the trick is matching the part to the technology. 

There are parts that can now be run on cam/CNC multis that only a few years ago we would never consider running on a multi-spindle machine at all. Now, worm gears made from tool steel can be machined complete on a CNC multi as well as other very sophisticated parts, at a competitive price since the pricing on CNC multis is more affordable.

The new challenge for your multi-spindle team is to look in all the options for screw machines: new technology CNC multis, new technology cam/CNC/multis and new technology cam multis. Then you know you have checked for the most competitive solution.

One lesson I’ve learned in my many years in the metalworking industry is that applying the right level of technology to a given job is most cost effective on the machine purchase end and most profitable for a job’s production run. Multi-spindle technology is at the point, both electronically and mechanically, where it is no longer necessary to choose one or the other to finish a part complete in one process step. This is a key to success in today’s competitive environment.