When a prominent West Midlands subcontractor won a new long-term contract for machining con-rods for the yellow goods industry, it called upon MAPAL for its cutting tool expertise to reduce costs and improve productivity.
Machining over 15 con-rods on a daily basis with a contract term at a minimum of a two-year period; efficiency, process reliability and cycle time reductions are three key parameters the Midlands based manufacturer sees as critical factors in the project. The Internal Engineering Consultant at the Birmingham business had a previous relationship, so five months ago the company sought out MAPAL’s experience for reaming a 40mm diameter bore.
Commenting upon the application, MAPAL National Sales Manager, Mr Eugene Nugent says: “The customer involved us at the very start of the process, based on our reputation for automotive tooling solutions and con-rod machining. The cast steel con-rods are hardened to 62HRc, which makes them a challenging proposition. In addition, the drilling operation leaves between 0.15 to 0.17mm stock allowance for reaming. We applied a 40mm diameter guide padded reamer and every bore now has an exceptional surface finish of less than 1.6Ra.”
The success of the 40mm diameter reamer opened that door for an opportunity to trial further tools on the con-rods. The MAPAL engineer identified an opportunity whereby a competitor end-mill was finish profiling hardened con-rods in a cycle time of 8 minutes. The 8-flute 16mm diameter end mill was expensive, had limited tool life and wasn’t demonstrating impressive productivity characteristics. Recalling this situation, Eugene continues: “The competitor end mill was very expensive and it wasn’t yielding the expected results, I ran trials with a 16mm diameter Optimill Uni end mill and instantly reduced the cost of tooling by 45%. However, this changeover was more than just a cost reduction exercise. The MAPAL Optimill Uni is running at 2500rpm with a feed rate of 1100mm/min on a very difficult material and the results have delivered a cycle time reduction of 3 minutes per part. With the finishing cycle being reduced from 8 minutes to under 5 minutes, this is a considerable saving for the customer that is also yielding a far superior surface finish.”
This cycle time reduction of 3 minutes per part saves upwards of 30 to 45 minutes per day on the HAAS vertical machining centre. Multiplying this daily saving over the term of a two-year contract really does emphasise the time reduction and tool cost savings provided by the MAPAL 16mm diameter UniMill end mill. In comparison to the previous end mills, the MAPAL end mill is extending tool life from 9 parts per tool to 12 parts per tool, a 30% increase in tool life performance.