Monday 9 July 2018
Have you always thought that a spindle moulder is not for you? Maybe you do not understand how it works, or just think that it is too dangerous or complicated to set up.
Incredibly versatile, its uses far exceed straightforward moulding work and it has some advantages over the router. It can also be used for a huge range of joints, grooves, rebates, box combing, etc, as well as for planing curved surfaces. You can sand with it, cut out shapes and even raise panels, the bigger profiles in particular being accomplished much more efficiently than with the router.
For much profile work there is nothing to beat the spindle moulder for speed, ease of use and quality of finish. The tooling for a moulding head is considerably cheaper than the equivalent large router bits and you can easily resharpen it or even grind custom shapes.
However, with its rather unfortunate reputation for being dangerous, the spindle moulder has always been regarded with some degree of fear, even by more seasoned woodworking machinists. A lot of this fear is historical, in that if carelessly set, much of the early tooling was inclined to shed cutters at high speed, causing serious injuries.
Nowadays, however, small, safe and easily adjusted machines are readily available, along with a huge range of complementary tooling designed to maximise safety. Spindle moulders are now as safe as any other woodworking machine, and once you have used one, you will begin to appreciate its value.
That said, however, using a spindle moulder does involve putting your hands quite close to a revolving cutterblock, and the cutters are much more exposed. The potential danger is compounded by the fact that the high speed of rotation often makes the cutters virtually invisible.
A spindle moulder therefore requires constant vigilance and concentration, but if you apply some basic common sense there should then be no more danger than with any other machine.
So what is a spindle moulder? Essentially it is just a heavy-duty spindle sticking up through a large table, onto which shaped tooling is fitted, usually in a cutterblock. The wood is then guided past it against a supporting fence.
Spindle moulder tables come in all sorts of shapes and sizes, in pressed steel, cast iron or aluminium. Obviously a big cast iron one is better, but the expense cannot always be justified. My own preference, apart from cast iron, is pressed steel as it wears better than aluminium. This may not be a consideration for other machines, but on a spindle moulder you do tend to use the same bit of the table all the time so any wear becomes more apparent.
Whatever else, the table must be perfectly flat and the area around the spindle usually has a large cutout to accommodate tooling of different diameters. Filler rings are supplied to reduce the hole size and maximise support when using small-diameter blocks.
The amount the spindle sticks out above the table is controlled by a rise-and-fall mechanism operated by a handwheel, the actual projection being shown on a scale. This movement determines how much, and where, the cutter profile cuts. Sometimes you may only want to use a small part of a moulding cutter, so the rest can be lowered down below the table.
It is important that this adjustment is free and easy, as you will often need to make minute alterations. It is equally important that the rise-and-fall movement can be locked securely at the desired height, so check that there is a positive lock and that it works properly. If it does not, vibration from the cutterblock can cause the spindle to lower very gradually during a run of moulding, resulting in a considerable difference between the start and end profiles.
The spindle is a plain 30mm-diameter shaft – earlier machines were one and quarter inches.
There is a massive array of tooling and any make is interchangeable.
The spindle is supplied with a series of spacing collars, which give you coarse adjustment for the depth of cut and the block is then held on with a special clamping washer and nut. There are all sorts of variations on the clamping method, but however it is done, use the proper tool on the nut and get it tight. Keep the spindle clean, and avoid doing anything to it that might damage it or throw up a burr, or you will find the tooling becomes very difficult to fit.
Some older moulders had what is called a French head. This was just a slot through the spindle that would take a simple straight cutter rather than a block. This system allowed you to make cutters very quickly for special orders, or where there was only a relatively short run of material it was a really handy facility. Unfortunately it was not the safest of systems and is not now permitted.
More professional moulders have tilting spindles which obviously increase the repertoire of the machine greatly, and sometimes the spindle itself is removable. This means you can set up a variety of tooling profiles on different spindles and swap between them without having to reset each time.
The motor is mounted underneath the table and drives the spindle via a belt. Shaping large profiles takes up a lot of power so the motor must be at least 2hp.
To accommodate the variety of tooling diameter it is important that the machine has several speeds. These are usually obtained by a stepped pulley arrangement. Expect a speed range of about 2500-10,000rpm.
More professional moulders will offer an electronic speed control system, but you must be able to see easily exactly which speed is selected. The consequences of starting up at top speed with, say, a large-diameter panel-raising cutter are scary, so a clear indication system is vital.
The switchgear must be mounted where you can reach it easily and a kick stop is even better.
Fence and guarding
The fence and guard is an integral unit, which clamps onto the top of the table with two locking studs. It is the movement of this fence backwards and forwards across the table relative to the block that provides the adjustment for the depth of cut.
Cheaper machines have non-adjustable fences which are never quite as good as an adjustable fence setup. In this latter case the outfeed fence can be moved independently of the infeed one to make allowance for any loss in timber width if you are making a full-face or planing cut.
It is also important that the faces of the fence can be moved sideways to close the mouth around the cutter block, so providing maximum guarding and support to the stock.
Moulding produces a vast amount of swarf, so a suitable dust extraction port should be built into the fence assembly. Better machines extract from underneath the table as well.
The guard itself takes many forms, but must provide pressure both down onto the table and horizontally against the fence. Conventional guards do this with independent arms for each of these planes and it is much easier to change the tooling if the guards hinge up out of the way.
In some cases it is better to make up your own sub-fences to provide extra safety and support, particularly if the work is small or difficult to support.
The ultimate, particularly if you are doing a lot of moulding, is to use a power-feed device which has motorised rollers. The feed speed can be varied to suit both the material and the profile being formed. The wheel cluster is adjustable in all planes and rubberised for maximum grip.
The main advantage of the power feed is the consistency of finish and it eliminates all those burns and marks caused by pauses when you change feeding hands. They are also safer, not only because your hands are now nowhere near the cutters, but also because they hold the work really securely and eliminate kickback.