Longbed CNC Machining

Introduction

As long bed CNC machines are not very common, here is a separate page to describe the technology with the hope it can educate on the uses and benefits of such technology.

Standard CNC machines usually have a smallish bed of upto 1 or possibly 2 metres if it is a very large machine. The head with the cutter is stationary and the bed moves around, cutting the metal as required. workpieces are often fitted in small vices or custom jigs often with multiple pieces per cycle.
Long bed machines clamp the work, mostly long sections, for example window frames, shower cubicle sections etc. These are held stationary and the cutting head moves in 4 axis, along the length work, changeing the tool as necessary.
This most often means that a section can be turned from raw extrusion to completed section in one operation. Interestingly, the programmer or operator need not worry about clamp location. If metal needs to be removed where a clamp currently is, the machine knows where every clamp is at any time and will move the clamp automatically during the live cycle.

An interesting feature of these machines, is that if the workpiece is less than half the length of the machines bed, the machine can be switched to Oscillating mode, where it effectively works as 2 separate machines - where one can be machining the workpiece or pieces while the other is being removed and re-loaded with fresh material.

Operator safety is assured by the machine being protected by laser beams - if an operator crosses these into the machines workspace, the machine is automatically cut off.

These are usually equipped with a multi tool changer ensuring all work can be carried out in one operation.

Programming of cutting operations is achieved either with the build in Windows PC and software, or for efficiency, this can be programmed off-line on a Windows PC, and copied upto the machine either by CD or the standard networked interface.

Specification

Elumatec Aluminium Profile Machining Centre SBZ 140
4th Axis
XYZ Travel : 7600 x 850 x 650mm
Spindle speed : upto 21,000rpm
Tool Changer : 8 positions - fully automatic