CNC Machine Installation: A craft paying rich dividends
Maintaining Right, Machining Right Part IV
Machine installation is a vital part of using a machine for service and is an investment for its reliability and serviceability for the complete service life. Proper installation results in consistent and reliable performance of machine tools. The following checklist will come handy for proper installation.
Machine Base Foundation
To achieve consistent machining accuracy, the foundation (flooring) on which machine is installed has a very crucial role. You can do machine installation in two ways. The levelling bolts of the machine rest on levelling units. At the contact area of these levelling units, the load is transferred to the flooring. The machine foundation must be adequately robust to bear the force of the levelling unit under static and dynamic loads. The floor bending should be within specified limits and should not disturb the machine levelling and geometry. The machine base can be locked to the foundation by various ways. The machine foundation is an integral part of the machine base. The advantage is that the machine base casting has limited weight, and the essential strength is attained by a reinforced cement concert foundation.
Machine Levelling
A machine is constructed and squared with respect to the machine table. So, you should make the machine base/table plane parallel to the ground. Such precision levelling decreases the Yaw, Pitch and Roll errors within tolerance limit. For a medium level machine, you should use the 0.020 mm/meter spirit level. For a large and precision machine, you should select a digital level instrument. For specific applications, a volumetric analysis software interface with digital level is useful.
Electrical Earthing
When a machine’s power is on and it is in operation, machine electronics component failure must be prevented. For this, you should connect the machine to electrical earth and only then switch it on. In earthing, the ground rod should be of a specific quality so that it provides the least resistance path. You should insert this rod in a soil that has been specially prepared, maintained and inspected periodically.
For CNC machines, you should use a separate electrical grounding. The ground wires of these machines should be systematically connected to a common plate/terminal and then to the earthing. Prior to machine connection, you should measure the resistance. The protocol is that earthing should have regular inspection and maintenance. Machine Geometry Inspection
You should set parameters such as XY Squareness, XZ Squareness and YZ Squareness within the test chart tolerance for a machining center.
Machine Lubrication
When you purchase a machine, the manufacturer recommends lubrication oils/greases and instructions to use them to avoid premature failure.
You should apply these lubrication oils/ greases to a ball screw nut, spindle and slide movements. Depending on the application, the manufacturer decides the lubrication and recommends lubrication oils/greases.
Some recommended lubrication oils are Vactra Oil No. 2 (MOBIL), Febis K68 (ESSO), Tonna T68 (SHELL) and Sideway
68 (CPC). Manufacturers recommended greases such as Mobilplex 48 (MOBIL), Energrease LS3 (BP), Spheerol AP3 (Castrol), Beacon 3 (ESSO), Gulf Crown Grease No. 3 (GULF), Alvania R3 (SHELL) and Multis 3 (TOTAL) and also hydraulic oils such as DTE 26/25 (MOBIL), Nuto H68 (ESSO), Tellus T68 (SHELL) and R 68 (CPC).
Shardul Itkalkar
Our specialist, Shardul Itkalkar, heads the Engineered Products division of Phillips Machine Tools India Private Limited. With more than two decades of industry experience, he advocates the right maintenance for your machines.He can be reached at
sitkalkar@phillipscorp.com