A small workshop may benefit from a machining centre that combines sawing, planing and moulding functions in one unit. Known as a combination machine, combi or universal, operations are usually based around a table saw and typically include a planer, thicknesser and spindle moulder. The table, or bed, is at the same height for each function apart from thicknessing, which has separate beds.
A factor that largely confines these machines to the amateur market is the difficulty for more than one person to work on one combination machine at a time. For this reason, most commercial workshops tend to buy standalone machines, of which there is a greater choice. Budget combination machines are fitted with one motor. By electronic switching or moving drive belts, the power is directed to the saw, planer or spindle moulder. More professional combination machines may have a separate motor for each function, although this adds significantly to the cost.
Most combination machines are equipped with induction motors. Those with several motors have a central control panel and are likely to have several stop buttons — an excellent safety feature. On/off switches should be easy to reach and, to comply with European regulations the saw blade and cutter block must reach a standstill within 10 seconds of being switched off. Because of the power required, larger industrial combination machines are generally only available in a three-phase (415 v) option. There is often a choice of single phase (240 v) or three phase for smaller machines.
Operating like a standalone table saw, you can use the combination saw for ripping, crosscutting and mitre sawing. You can usually tilt the blade to 45 degrees for making bevel cuts. Normally a TCT, general-purpose blade is fitted, from about 254-305 mm (10-12 in) in diameter. Depth of cut at 90 degrees can be anything from 85-100 mm (3 3/8-3 15/16 in). Rise and fall and blade tilt are operated with hand wheels. The rip fence extends the full depth of the table, which is usually cast iron, and slides along a front-mounted rail. Often shared with the planer, you may need to reverse the fence for surface planing.
A sliding carriage may be fitted as standard, or added as an optional extra. Fitted to the side of the machine, this device takes up even more space, but enables you to mitre and crosscut timber precisely to length. Extruded aluminium crosscutting fences are light yet sturdy, and used in conjunction with a sliding table.
Planer and Thicknesser
The cutter block may be fitted with either two or three knives, rotating at a speed of around 4,500 rpm. For thicknessing, the surfacing tables are usually for access to the lower adjustable bed. A guard covers the now exposed cutter block and incorporates a dust hood for connection to an extractor. Timber feed speed is about 6 m per minute (20 ft per minute).
A spindle moulder enables you to add profiles to straight or curved timber or to cut tenons with the wood clamped to a sliding table. Guards are essential and you should never use the machine without them in place. A circular recess or well in the table enables you to raise the spindle above the table. To insert the cutters you must first engage a lock to prevent the spindle rotating. Spindle diameter on European machines is commonly 30 mm (1% in), rotating at a speed of around 6,000 rpm. Two-speed spindle moulders run typically at 3,000 and 6,000 rpm.
There will be several ports for connecting an extractor hose. Besides one at the rear of the saw, there is likely to be a smaller diameter outlet on the crown guard. The planer and thicknesser usually share a port, while a spindle moulder horseshoe fence will have a separate outlet. A mobile dust extractor will be adequate, although you may wish to install a fixed system for convenience. Standard outlet diameter is 100 mm (3% in).
Some combination machines enable you to fit a mortising attachment on the side of the planer. This consists of a horizontal machining bed to which you clamp the timber. Levers or rods enable you to move the timber in towards a rotating cutter, as well as laterally. You insert the mortising cutter in a chuck mounted on the end of the planer cutter block.
Word Discription :
Crosscutting Sawing across the direction of the grain.
Crown guard Adjustable steel or plastic safety cover above the saw blade.
Cutter block A cylindrical steel or aluminium block into which straight or shaped cutting blades are locked. Found on stationary surface planers and spindle moulders, but also power tools such as portable planers.
Ripsawing (ripping) Cutting parallel to the grain of the timber.
rpm revolutions per minute
TCT Tungsten carbide tipped