INITIAL SITUATION
- The machining center is used to manufacture chrome-molibdene steel gears (20 Kg per part)
- Scrap rate over 30% due to dimensional and geometrical characteristics
- Production rate of 16 parts / hour and the need for change of the toolings every 10 parts due to wearing of the inserts
PROJECT DESCRIPTION | APPROACH METHODS
- Definition of initial situation and targets
- Measuring machine performance using Ppk as indicator
- Definition of machine parameters affecting characteristics
- Definition of an experimental layout to test the machine parameter effects at different levels
- Developing of 18 experimental tests and measurements to obtain data and statistical items (average and variation)
- Analysis of results and definition of the best parameters combination (improve runout and reduce variation)
- Validation run and measurement of improvement
- Standardization of new machine parameters
PROJECT RESULTS
- Scrap reduced from 30% to 0%
- Machine stop frequency to change worn tools was reduced from 30 parts to 10 parts
- Tools consumption reduced to 1/3 of initial
- Ppk increased form 0.25 to 3.06 (0.5 sigma to 9 sigma)