Slim Milling Chuck Provides High Gripping Force
Big Kaiser has launched the HMCJ, a super-slim milling chuck with peripheral coolant supply, designed to support heavy-duty and finish-end-milling tasks with power and precision using ½"- or 12-mm-diameter cutters.
Big Kaiser has launched the HMCJ, a super-slim milling chuck with peripheral coolant supply, designed to support heavy-duty and finish-end-milling tasks with power and precision using ½"- or 12-mm-diameter cutters. The newest, slimmer member of the Hi-Power Milling Chuck (HMC) family features a clamping bore with fine slots surrounded by hundreds of needle bearings, which ensures concentric, precise and smooth clamping when the nut is tightened. The HMCJ provides high gripping force to the cutting tool shank, as much as five to six times greater than collet chucks, the company says.
The slim, yet rigid design of the chuck reduces the nut diameter to 1.260" (32 mm), the smallest in its class, Big Kaiser says. The chuck maintains a cross section of 0.394" (10 mm) to prevent chatter and promote cutting security. The maximum jet-through coolant pressure is 70 bar.
Despite being designed for heavy cutting, the HMCJ milling chuck can maintain a runout accuracy of 10 microns at 4×D, giving it additional flexibility for use on finishing applications. For additional rigidity and accuracy, the CAT and BT interfaces are Big Plus as standard, but a Big Plus spindle is said to be unnecessary to achieve performance with the chuck. A 32-mm, straight-shank design is also available.
It is also possible to use smaller-diameter milling tools through the use of PJC reduction collets. The 0.500"-diameter HMCJ can then accept 3/8" and ¼" shanks, and the 12-mm-diameter HMCJ can accept 10-, 8- and 6-mm shanks.
A system to be marketed in 2015 will apply ultrasonic vibration from within the toolholder to reduce cutting force and improve the performance of the cut.
The retention knob is an unmistakably critical component of the machining process. However, the tightening of the knob itself can lead to the toolholder not seating securely in the machine. You may be losing tool life to knob tightness without even knowing it.
Companies concerned about strict quality requirements regularly check toolholder tapers for wear or inaccuracy because these conditions can jeopardize the results of a critical operation. However, a shop can check tapers quickly and reliably with air gages. These devices can be used effectively without special operator training. For measuring taper in a production environment, few other methods can match the speed and performance of air, as multiple-circuit air jets can be placed in very small taper gages.