The 2.5 Million Dollar $0.07 Spring
 

I am a new engineer at a giant machine shop. There is a particular machine which has been a process bottle neck. Overtime is constantly required and additional personnel have been hired to attempt to solve the problem. I have been given the opportunity to evaluate the cell including changeover (SMED) and other "Lean" activities. I was working with a operator who was running the machine for the first time in 4 years. I inquired about the RPM range of the machine and calculate the surface feet/ min we were currently running, only 1/3 of what was capable. There were 2 handles wired together with copper wire to prevent movement of the handles as they were reported to be flopping around which would cause the gearbox to come out of gear. The operator said they were like that 9 years ago when he was hired to run the equipment and his predecessor advised him not to touch it. "That is how it has always been." he said.

We cut the wire, and indeed the handle is flopping all round. It is a gear selector handle which allows 5 main adjustments of speed. There is another gear selector which takes care of the fine speed adjustment with 8 different speeds selectable. All together there are 40 speed adjustments ranging from 10 RPM to 1300 RPM. After further inspection we noticed, covered with 3 layers of paint, what looked to be a cap to a spring loaded detent ball. We removed the cap and sure enough the ball was there but no spring! That is the cause of the handle flopping around which caused the machine to jump out of gear. The machine was throttled down to the lowest gear by wiring the handle with the copper wire. We located a $0.07 spring to install into the spring detent and viola the detent handle and gearbox worked as designed. So instead of having only a speed range of 10 RPM to 25 RPM we now have once again 10 - 1300 RPM.

All the bottlenecks which we have experienced over the past 9+ years should be eliminated with a machine that can now operate at capacity. Running the numbers, this $0.07 spring has costed us $2.5M.

There will be changes coming to how we do things!

Speedy:)

Nice job.
I see this all the time at customers' facilities. What kind of machine is it?

1950's Giddings and Lewis boring mill.

Wow, what's nearly as mind numbing as your story, is when you think about, someone at some point in the past, removed/lost the spring and didn't think anything about it when the machine stopped working right?

Any screw machines?

As in machines that make screws? Yes, we have horizontal turning lathes, which do our screw work, vertical turning lathes, horizontal milling, vertical milling, horizontal boring, laser cutting, welding, automotive paint booths and lots of other processes. One milling machine has a 30' X travel. It is HUGE!

Speedy:)

great story for a small/short case study!

I'm wondering if you have any multi-spindle screw machines. ACME, Davenport, Tornos, Euroturn, Index. 5, 6, 8 spindles? They make more than just screws. Usually 2-1/2" diameter down to very small diameter parts.

It is a good example of how everybody is responsible for the success of a company.

If maintenance took the initiative then...
If the operator took the initiative then...
If the engineers took the initiative then...
If the leadership asked the right questions and saw for themselves then...

What kills me most is there is a maintenance leader who perpetuates the toxic thinking that it is acceptable a machine leaks oil, runs slower than designed, or is sloppy just because it is old. Each machine in the shop should at least be as good as when it left the factory, if not better!

Change is a coming.

Speedy:)

We do have 1 horizontal turning lathe with live tooling. So 2 spindles. We use the machine to make shafts with threads and keyways.

Speedy:)

Call me jaded, but I've been playing this game for almost 30 years. One possible scenario is that some operator removed the spring. He was likely reporting up through some sort of management structure with no technical or engineering background, and therefor nary a clue as to why the machine now only had one speed. He probably told them it was really expensive to fix the old machine. He wanted overtime.

The second, more likely scenario is the company simply had no one familiar with the machine. Any genuine card-carrying journeyman machinist, or any old engineer with any sort of machine shop experience whatsoever would have taken one glance at that old Giddings and Lewis and would have had a very short list of things to check. I bet they are too cheap to hire journeymen and, up until you, have been to cheap to have a real engineer involved.

I deal with this all the time with the mid size shops we contract with. The really small shops tend to have experienced old hands who would pick up on this one on the very first day it broke.

Union shop?

Sounds like you have plenty of opportunity for improvements.
I automate machine tools for a living. Simply put, I design control systems for machinery that will dramatically improve the efficiency/output of the machine/operator. Let me know if I can help. Good luck. Your biggest hurdle will be the "that's how it's always been" thinking.

Engineers are born and not all engineering types hold a degree!

When my buddy Tim was working for his former FIL at his connecting rod shop, he hit into all sorts of problems with the union doing this kind of stuff. Multiple grievances were filed. He ended up quitting because the union simply wasn't interested in making the business profitable. He ended up in big trouble with the union when he simply wanted to swap the order of two operations. Hope you don't run into this.

Wow... Just wow.

Poor employees haven't operated at 1,300 RPM in a decade. Watch your back. :D

Non-union, but there are some ex-union folks which harbor the same mentality just on an undercover basis.

This will be run up the flagpole.

Red88Carrera,

Before going back to school for my BSME degree I worked for an injection molding company. We had some older machines we updated the controllers on and tuned the valves for quick response. We made those old machines better and faster than new and was on par with brand new equipment. It was satisfying work and it was amazing working with people pushing the envelope. Please PM me your contact info.

Speedy:)

When I was a test engineer at a union shop, the operators and I became good friends. As time went by I realize I wasn't going anywhere and they knew it. The union guys that worked in my department basically told me I had to get out of there or I was going to waste away. I did. Great guys who themselves knew the union was screwing with production. Or maybe they just didn't like that I automated our test line.

Start by firing this nonthinking fool.

This story makes me want to cry.

Good for you doing a good job. All it takes is one person to di the right thing to change things.