What is Lean Manufacturing?
Technical
Written by Murali K Mutyala   
Tuesday, 09 December 2008 12:32

Lean Manufacturing – A More Profitable WayThe typical waste in most manufacturing companies is about 70 to 90% of their available resources during manufacturing. It is a difficult process to reduce the waste; even a best Lean Manufacturing Company can have around 30% wastage of its resources. There are so many factors contribute for the wastage of plant resources.

Lean manufacturing is a technique to reduce the waste in a manufacturing process. As a result of lean manufacturing techniques, several companies are thriving, operating with less waste and using fewer resources to produce quality goods. They achieve these through special Lean control methods.

The benefits of lean manufacturing include:

  • Reduced lead time

  • Optimized plant space

  • High productivity

    Better product quality

  • Faster delivery schedules

 

Many companies also realized that higher employee morale in plant, because lean manufacturing includes listening to workers and their ideas about how to run things better.

 

There is a lot of information available about lean manufacturing over the web, however we are trying to give you just the brief concept here.

Nesting the parts while machining using CAM

While working on a recent CAM project using CAD model, we found few interesting techniques. In the first job, we requested the operator to use a 1/4″ Ball nose cutter of 1″ long. We were expecting there could be some tool flexing because for the first cavity profile cut. But he used almost 1 1/2″ long cutter. Finally, once the machining is done there is a clear cut draft left on the part which is almost 3 degrees. Also, there was not enough overpass of ball nose at the bottom of the part leaving a radius there. It was not too bad other than doing some manual cleanup of the part after machining.

In our second batch of CAM, we nested four parts as shown on image from two separate CAD models. So, we have to make a single pre-machining block to make two separate parts of quantity two each. Also, we tried to machine only up to 4 mm around the part using 1/4″ cutter. This saved us almost 50% of machining time as we eliminated machining unneeded stock. Also, we ensured the cutter overhang is only 22mm just more than nose overpass. This didn’t cause any tool flex and squeak.

Nesting the Parts example

Nesting the Parts example

 

Another interesting thing is after doing the rough cut with 1/4″ cutter, we lost the datums where we set original zero. So, for finish cut we have not changed X and Y coordinates. But, asked the operator to reset Z with respect part top surface which was intentionally left unmachined before. This helped us in quickly running the finish cut using 1/8″ cutter without much time on reference point set.

Hope you found this article useful. Please share your comments below.