how creativity results in major cost savings

Identify the area of improvement

The first and foremost process is in the development of ideas is to set the target or destination. Your road map may be misleading, in case you don't keep your eyes on the target or don't analyse your progress against the set goals. Milestones are the important gateways to measure your performance and keep you on the track.

In year 2008, i was working as an Engineer in agricultural tractor OEM based in INDIA. We were frequently receiving tractor model from different area of the world for bench-marking and analysis.

The one model aesthetically very appealing came from France, after dismantling it's body panels in the proto shop, me and my deputy manager were observing it's internal body parts. He was astonished to see the fuel tank and battery box were made out of carbon fiber and many more parts were optimized for weight reduction. Finally engine was being opened and it's oil sump was even made of carbon fiber.

At the moment, i suggested to my manager that the world is adopting the carbon fiber in many body parts, at least we should take initiative to convert the engine oil sump from casting to sheet metal.

Since carbon fiber is more more prone to cracks due to it's brittleness and it's implementation would not suit with the nature of Indian mechanic, who gradually uses hammer etc to loosen it's nut and might have cracks during such striking.

The idea sets its home in the mind of my manager and he eventually decided to take it further.

Sheet metal oil sump Casting oil sump

Set the target of improvement

Nevertheless, the target has been set, we are in the process of starting it's concept design mainly for weight calculations and difference among casting part and fabricated one.

After calculations, there was a major cost saving the weight has been reduced by almost one third.

Start the concept design

After the hard work of one week, Now it's time to present the idea before the management team in a presentable form. My team lead has made a presentation of concept design along with weight and cost saving, thanks to 3D cad packages which helped us to give shape to our idea in presentable form with realistic look. The tentative time plan has been developed for proto sample and testing activities.

During the presentation, the main bottle neck comes out as to maintain the flatness, since casting has a machined face and it should have been through metal stamping. As the gasket is being used in between both contact faces as dampener and to prevent oil leakage, it was decided to at least try out at testing level.

Generate your idea, Study the scope of potential failures

The idea has been generated and approved by the management for making at least proto samples and test it out for minimum 750 hours. The main big challenge is to make it's manufacturing flow diagram, since it was a deep and narrow part, never tried out in a sheet metal. At that time we were using FEA package to study the form-ability of skin panels, the same has been tested to make it's process flow.

After producing the part through incremental forming analysis, the defects like excessive thinning and wrinkles etc. were eliminated.

Now the only potential failure was to maintain the flatness, even though the metal spring back analysis has been done and appropriate actions were being taken, the risk was still present there.

Advance planning to overcome the failures

Although, the many issues were even resolved at the design stage, the nuances were still there, faced during trial phase such as material crack during forming. Which further has been eliminated by enlarging the radius and adding draft at certain places, shape optimization technique has been used with the help of FEA software. The final proto samples were made and eventually there was huge gap in the flatness values of machined and stamped part.

The stamped parts were appealed to be rejected, however have passed the fitment and oil leakage test after final assembly, the spring back killed by the pressure of bolt torquing.

Take expert help to overcome bottle necks, in case it is available

In our proto shop, there were some experienced tool makers, which have suggested the major shape modification in order to make it feasible to form. Such experts have a years of experience, enough to beat the calculations of the software, when he see the part it looks like if the metal part is telling him the way, how to produce me in the correct manner.

His suggested points produce excellent results when tested on FEA software. Such expert help wold boost your confidence and reduce your overall lead time.

Some problems are hidden and becomes visible during trial phase

During testing phase there was a minor leakage problem observed at nut welding area, where the oil is being drained out during servicing and changing engine oil. This was the hidden problem occurs suddenly during torture track test, every vehicle with any new part is subjected to torture track test for 400 hours, before launching in to mass production.

As a concrete action, the pressure leakage testing rig was introduced to prevent it in future mass supply.

Final mass production launch

After correcting all the problems faced during field trials and testing the product was finally launched in to mass production. It has not only saved a lots of money in current mass production models, but also open up the way to implement it in the future models as well.

If you want to learn the Metal forming simulation, read the book "Practical guide to forming simulation"