- What you don’t need to mill by hand
- Milling table and milling machine
- Types and features of milling machines
- Key parameters
- Basic and special equipment
Milling is an advanced carpentry operation, which gives rise to certain requirements for the capabilities of the equipment. You will learn what is the fundamental advantage of machine milling over manual and about the types of stationary equipment for the home workshop.
What you don’t need to mill by hand
There are many milling techniques that can be performed with a hand router, which is why this tool is considered extremely versatile. But its capabilities are limited for a simple reason: there is no guarantee of the correct position of the tool relative to the workpiece with a significant overhang and cutter size. In other words, the runout of the spindle or the departure of the cutting tool with a loose fit of the sole does not allow for a good quality of processing..
You need to be well aware of the practical difference in the equipment of different classes. If the hand router copes well with milling the end of the countertop, then the manufacture or refinement of wood decors requires a better base. This is especially important when milling parts of small width and thickness: plinths, glazing beads, small moldings and the like..
The main advantages of the machine are good repeatability and stability of settings. If you have a powerful motor – even better, then massive workpieces can be milled in one pass, achieving excellent quality. The size and weight of the cutters that are used with the machine are slightly higher than for manual cutters. There is another factor: the efforts aimed at holding the tool in the hands during constant work tire you, therefore, with at least some pronounced serial processing, the quality by the end of the series can be very different. Finally, the work on the milling machine is simply faster..
Milling table and milling machine
Before giving recommendations on choosing and buying a milling machine, it would be nice to talk about those situations in which it is not required. The construction of even the simplest table for hand tools significantly expands the possibilities of milling, so that some of the work for which the machine is designed can be performed on lighter equipment.
On the milling table, you can perform small-scale machining with those dimensions and types of parts that are allowed by the design and capabilities of the router. Chamfering, edging, decorative milling – all this is within the power of a stationary hand-held tool. Milling of ends and large-sized flat parts is also possible, it is only enough to correctly make a stop with a sufficiently large contact plane.
Ultimately, the milling table repeats the fundamental structure of the machine, but there is one key difference between them: the mass and rigidity of the spindle, which are almost impossible to achieve by making the bed with your own hands. Thus, if the need for high precision and cleanliness of processing is urgent, the purchase of a milling machine is inevitable. The same if the processing of a part requires a long adjustment and basing, which are unacceptable in mass production.
Types and features of milling machines
The simplest milling machine has only a table, strictly perpendicular to the plane of which a spindle is installed and rigidly fixed. It can be stationary, but much more often it is mounted together with the engine on a movable platform, which moves along a vertical axis in a small interval by a power feed device. The highest quality spindle fit is ensured when using a quill, which is typical for machines with a V-belt transmission. A parallel adjustable stop is attached to the table of even the simplest machines.
More advanced machines have the ability to tilt the spindle in a plane perpendicular to the stop. This is necessary for chamfering with a straight slot cutter or changing the geometry of the cut edge. Together with height adjustment and a basic set of disc and end mills, the tilt of the spindle allows achieving a high variety and complexity of milling contours, it becomes possible to simulate the operation of a profile cutter.
Machine tools with a sliding carriage are even more advanced. In addition to the main table, they have an additional one that moves on a longitudinal sliding feed, which ensures the possibility of rigid fixing of the part. This is indispensable when processing large-sized products or, if necessary, to ensure high accuracy and cleanliness of cutting. Also, the table can have a mechanized feed for finishing cuts with large and shaped cutters..
The most complex type of machine from a technical point of view is copy-milling machines, but even they are used in home workshops focused on mass production. The location of the spindle in these machines is top, there is a longitudinal and transverse feed of the table, as well as the possibility of vertical movement of the carriage. In fact, such machines, unlike classical ones, are focused on milling not edges, but planes of parts, they can also copy a milling pattern using a scaled template and a leash on a pantograph.
Milling machines can have special functions:
- Switching between separate and synchronous adjustment of the stop strips.
- Rulers and scales, including digital indication.
- Automatic feeding.
- Spindle lock.
- Speed control (electronic or transmission).
Additional options include special stops, means for securing and locating the part, various types of accessories. For the most part, these additions are aimed at improving the comfort, speed and safety of work, which is considered the main subject of competition for machines, along with the overall reliability and quality of workmanship. But you should not make hasty decisions, because the tooling and refinement of the machine is a profitable business, the reliability of the main units is much more important.
The most important characteristic of the machine is its power, which is determined by the type and performance of the engine. For a home workshop, the power of the machines is almost unlimited, however, equipment with a drive more powerful than 3 kW is rarely used, in small-scale production this is simply not required. If the task is to process large and bulky parts, remember the following: a machine with a powerful motor, as a rule, requires a three-phase connection. In single-phase networks, the machine can also be used with sufficient permitted power of the network and the presence of a variable frequency drive.
Almost always, the size and massiveness of the desktop grows in proportion to the power, but there are exceptions. With their ergonomics and layout, the machines determine the format of the workpieces: massive and compact or large and lightweight, such as sheet materials. So, if you plan to milling parts for wooden doors, the width of the table should not be less than 600 mm, for the manufacture of furniture facades – about 1200-1300 mm. The milling machine is not designed to operate if the length of the part along the milling line is three times the width of the table and twice without a support device.
The rigidity and accuracy of the machine can be judged by the permissible size and weight of the cutter. Among the main features are a high-quality spindle seating system, the number and type of bearings in the assembly, correct prediction of the acting loads and good dust protection. Special attention should be paid to the mechanized spindle feed: how the guides are made, is there a parasitic backlash in the mechanical transmission units.
Basic and special equipment
The delivery set of the milling machine must contain all the tools used to assemble and configure it. This is especially important if there are screws with special slots in the design or various mechanisms with removable handles. Of the mandatory components, a normal milling machine must have a parallel stop with a protective cover, a set of spacer rings, a cross stop, a pusher and a protective screen for the working area, as well as replaceable collets for different diameters of the cutter shank.
The list of special equipment is more extensive, the most popular manufacturers complete their equipment with different sets of accessories. For example, a front clamping bracket can be supplied with the machine to facilitate handling small parts. This unit differs from different manufacturers in terms of the technical solutions involved, which can be more or less convenient when performing certain operations..
For irregular parts, a starter pin, which is used when milling curved edges, or an adjustable corner stop for bevel facing, will be useful. The possibility of using this kind of equipment should be provided for by the design of both the main table and the movable carriage. This is mainly realized by means of a longitudinal groove (T-shaped or “Dovetail”) and a series of expanded blind holes.
To mill parts in a standing position, for example, when cutting box grooves, a vertical stop with several clamps for secure fastening and travel stops is used. Milling with a template is also possible, for this either a thrust pin screwed into the corresponding hole in the table can be used, or a set of bearings that serve as part of a compound cutter.
Any additional equipment of a wood milling machine increases the versatility of the equipment and expands the range of available milling techniques. For a home workshop, this is very important, and although we do not recommend making your choice solely by a set of additional accessories, it is still worth familiarizing yourself with the general list of accessories supplied by the machine manufacturer. In this case, high unification will facilitate further setup and will allow, over time, to acquire a more productive version of the machine, while retaining all the auxiliary equipment..