Mirror Edge Chatter Reduction
Special cutter geometries exist today that are specifically designed to eliminate chatter, regardless of the application. Their tooth-passing frequencies will always match the part frequency, whether the spindle is spinning at 40,000 rpm or 2,000 rpm. This allows the mold builder to consistently run the maximum spindle speed available on the machine without producing chatter or vibration. This, in turn, means he can cut material faster without producing poor surface finish, and it increases cutter and spindle life. This vibration-cancelling geometry at the end mill’s extreme cutting edge causes the vibration of the part and the vibration of the end mill to match frequencies. Things are still vibrating, but they are vibrating in unison, so the part and the cutting edge are at the same place in space as the flute cuts the material. Each flute cuts the exact amount of material that it is programmed to remove. When chatter is present, each tooth is making erratic cuts in the material, causing the chip load to be extremely heavy on one flute and preventing the following flute from contacting the part. This erratic engagement of the cutter perpetuates the problem and causes the self-excited chatter.
Correct alignment lock selection will reduce maintenance costs, molding downtime and increase part quality over the mold’s entire life.
How-to, step-by-step instructions that take you from making the master pattern to making the mold and casting the plastic parts.
Understanding the effects of injection on the core, slide and associated components is critical to selecting the best side-action methods for a given application. This first of two articles will discuss the basic physics underlying all side-actions.