How to choose a CNC woodworking machine: selection criteria, types and power
Modern woodworking machines are not just a pile of metal with precise mechanics, and computerized and automated technically complex devices. Using numerical programming and computerization increases productivity, improving the accuracy of work performed.
How to choose CNC machines for woodworking?
Woodworking equipment is widely used in furniture workshops, at industrial woodworking enterprises, in design centers. When choosing a CNC machine for woodworking, you must first determine the following parameters.
Dimensions of the table of a CNC woodworking machine
Usually, the size of the table of the CNC machine indicates the maximum processing area and the possible dimensions of the workpiece for processing. You need to decide, for which products and purposes the machine will serve, will be it:
- carved interior decor elements;
- facades of doors;
- overhead parts with wood carving.
The dimensions of the table must overlap with the maximum dimensions of the part.
For an overhead carving it is possible to establish a table in the size of 550х850 mm. For finishing carved facades, carved frames, wall panels, paintings - the size of the table should be around 1300x1300 mm. To make a door, the size of the tabletop must match the dimensions of the door, and can be in the range of 1200x1700 mm or 1200x2600 mm. A CNC machine is suitable for processing small souvenirs, which has a tabletop size of 320x320, 380x380 or 420x420 mm.
Spindle type and power
It is necessary to tell at once, that collector electric motors, which are used on hand-held devices such as "cress" and "Makita" for professional processing are not suitable. They can be used for cutting 30 minutes, or mill no more 5 minutes. Duration of continuous work during 9-15 hours (often more days) they can not stand. Only asynchronous motors with a frequency converter will be able to work for a long time.
What power spindle to install for processing different materials
For the production of small souvenirs, jewelry models, overhead carved wooden elements is enough to choose a power spindle 1,6-2,3 kw. For milling wood to a greater depth 7 cm, cutting and cutting of multilayer plywood, cutting of MDF by file mills - power of a spindle is selected not less 2,9 kw. You can choose a spindle for milling fluoroplastic products 1,6 kw.
Spindles differ in the method of cooling: water or air. Usually, in woodworking convenient and inexpensive in work of a spindle with water cooling are applied.
Product height
The thickness or height of the product affects the height of the "Z" point when selecting a CNC machine. This is the distance from the tabletop to the beam, where the spindle carriage is fixed and moves.
For the manufacture of promotional products, cutting materials, wood carving it is enough to install a CNC woodworking machine with a height of the coordinate "Z" 110-160 mm. When machining solid and large wooden parts, you can install a machine with a height 210-310 mm and above.
management method
There are three ways to manage:
- port and computer, usually, LPT;
- control board and computer;
- standalone remote control.
The first way is amateur, and not suitable for professional work. The second option is to purchase a computer, convenience is, that the processing is displayed on the monitor, processing emulation is possible, one PC is enough for simulation / preparation and cutting of parts.
The main advantage of the remote control (NC Studio) - full integration with the machine, even when the power is turned off, the CNC machine will remember the position and start working from the end, ease of operation and good protection against dust. A computer is needed to compile a numerical program for hardware.
As practice shows, when choosing a woodworking machine with automatic tool change, with rotary axes or with several spindles - it is better to install NC Studio control. This system ensures the correct operation of all organs and systems of the CNC milling machine.
reliability
In this case, the main parameter is the weight of the machine. If you are offered a machine 1300x1300 weighing in 250-350 kg - this indicates poor performance and poor design of the installation. For efficient operation, this equipment must weigh 450-550 kg. Also the efficiency of work is influenced also by a complete set of the device by qualitative parts and knots.
CNC woodworking machines can be developed taking into account the processed material and in the performed tasks of several modifications: difficult, average, light. All series of the machine differ in weight, intersection of installed metal structures, frame design, etc.. D. All this affects the price of equipment.
Precision / speed
High-speed CNC woodworking machines are quite expensive. These are devices with powerful high-speed spindles, with automatic tool change, with servomotors. More economical and proven in woodworking - devices with stepper motors. The choice of electric motor for CNC machine will depend on the type of milling, processed material, tasks.
In the middle range of the cost of CNC machines in the role of the drive set, usually, toothed rail transmission or ball-screw pair. Screwdrivers are a great choice for small devices, speed of their movement 7-11 m / min, accuracy to 0,03 mm each 30 cm in length.
The rack is accelerated to 25-45 m / min, milling accuracy is slightly lower - 0,06 mm each 30 cm. For cutting and milling chipboard, wood, polyamide, acrylic, composite of this, usually, enough.
How a CNC milling machine works?
The data of the required product is set on the computer using an input device. After downloading the task, computer, using the appropriate program, gives commands to the control device, management of the equipment to obtain the finished product.
In practice, this is how it happens. A wooden blank is attached to the work piece. Having a complete drawing of the details, the operator gives a few simple commands on the control panel, which indicates the set of necessary tools, the order of their replacement and the route, spindle speed. Then the program starts and at the exit we have the finished part.
