Video: Safe Shrink-Fit Has Built-in Cooling
The cycle for heating the toolholder also includes water cooling so the toolholder finishes cool.
A shrink fit toolholding system heats the toolholder to expand the bore, then allows the cooling of the toolholder to shrink the bore around the tool shank and clamp it. Safety is a concern—users wear heavy gloves to avoid contact with a still-hot toolholder. This video from Techniks shows a shrink fit system supplied by the company that addresses that concern. As part of the heater’s cycle, the toolholder disappears briefly into the housing of the unit, where it is soaked with water. The toolholder is cool enough to touch by the time this cycle is complete.
One of the most common methods of tapping in use today on CNC machines is 'rigid tapping' or 'synchronous feed tapping.' A rigid tapping cycle synchronizes the machine spindle rotation and feed to match a specific thread pitch. Since the feed into the hole is synchronized, in theory a solid holder without any tension-compression can be used.
With macros and canned cycles resident in the CNC on most contemporary turning centers, single point turning of OD threads can seem like almost a default process decision. However, for numerous applications, OD thread rolling has inherent advantages as an alternative to cutting threads.
Reducing cutting fluid use offers the chance for considerable cost savings. Tool life may even improve.