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Choosing a lathe for woodturning

It’s easy to get it wrong when choosing a lathe. That can greatly restrict the work you can do, or prevent you enjoying woodturning, the very thing you are buying it for. There are so many machines on the market, some of such poor quality that they can only be used for very light work. How do you choose between them?

To perform well, a lathe must be designed well and made well. Top quality doesn’t come cheap, but even inexpensive machines can be compared when choosing a lathe to see which is the better buy. Good quality lathes last indefinitely and often a used one is a better choice than a poor quality new one, even if you have to replace bearings or scrape off a bit of rust or change the motor from three phase to single phase.

Few suppliers advertise that their lathes are of poor quality, so you have to make up your own mind which is best. You can consult other turners, but when you are choosing a lathe, it’s your money. The best approach is to make sure you understand what makes a good machine. When you have examined lathes from different price ranges you will see the differences and be able to make an informed choice.

The perfect lathe  does not exist, and never will, because so much of the design of a lathe involves compromises. For example,  a short bed lathe takes up less space and is easier to use, but will limit the length you can turn. Nor is there such a thing as a beginner’s lathe or starter lathe. Either a lathe is a good one or it isn’t, and a beginner is not well served by a poor quality machine that causes problems in use. You can compromise on size or variable speed if cost is important. But don’t compromise more than you have to on build quality. Weak components and poor manufacturing tolerances may make the lathe almost unusable for anything but very light work.

Here is a checklist.

Size

The first thing to consider when choosing a lathe is size. A big lathe is the most versatile, as although you can do small work on a large machine, the opposite does not apply. Many of my bowls could have been made on a small lathe, but not all. Bigger lathes, made primarily for more experienced turners, are also usually of better quality. The biggest can still do small work, though they sometimes cumbersome. For example the toolrest holder and tailstock will be heavy to move.

But if you have limited space or budget, a good small machine will be fine for small work, and the better ones are very capable. The smallest machines, micro lathes, should only be considered if you have a particular need for one, for example if easy portability is critical. Even if you only want to make very small items, a larger machine will probably be easier to use. Drill-powered lathes are also unsuitable for general use, because of their light construction and the noise they make.

Rigidity

When choosing a lathe and comparing machines, look for:

  • a strongly constructed headstock with a large diameter headstock spindle, mounted in heavy-duty bearings that are well separated. The spindle nose thread should have a wide register at the back to support the chuck butting against it. Except on small lathes, the spindle should accept number 2 or larger morse tapers.
  • a strongly made tailstock,  that on bigger lathes can accept number 2 or larger morse tapers
  • a robust tool rest and support
  • a substantial and rigid bed
  • a strong and stable stand or bench that will support the lathe without shaking.

Look for key components made of cast iron or heavy welded steel. Cast aluminium, thin pressed steel or light weight tubular components may not be rigid enough, and heavily stressed screw threads in aluminium can wear rapidly.

Cast iron or steel bed?

It is often said that cast iron is the best material for lathe beds because it suppresses vibration, and there is some truth in this. Lathes with flimsy, light weight beds made of pressed steel are really only suitable for light work. Steel tube beds or solid steel bars can flex and vibrate, but the heavier and stronger (and shorter) they are, the better the lathe will be. Cast iron can be brittle, so is usually made quite thick and heavy out of necessity, which tends to be a good thing. A heavy cast iron bed with good cross-linking webs connecting the sides will be the foundation for a good machine.

But some top end lathes have steel beds. Heavy steel plate is welded to a heavy steel tube, round or square. The assembly is large enough to prevent twisting and flexing. Vibration on these is not a problem.

The tool rest and holder

When choosing a lathe, pay particular attention to the design of the tool rest and its holder (sometimes known as the banjo). These are key components and any weakness will prevent smooth, chatter-free cutting, particularly when using scrapers. This is specially important if the lathe has a swivel headstock as you may have to extend the holder far off the bed. The greater the overhang, the stronger the components needed to resist flexing under load. Some may bend or even break if the tool catches. Avoid rest holders with lightweight jointed swing arms. If the holder has a cam lock, it needs a heavy and rigid eccentric spindle, otherwise the clamping force will vary depending on where the holder is. Access for adjusting the tension should be easy. The hole for the toolrest stem should be deep as this will help prevent it flexing under load.

The toolrest itself should be heavy and strong in proportion to its length, with a large diameter stem. But the most heavily built rest will flex if it is too long and only has a single stem. You need a robust rest but one with a narrow top, to put the fulcrum for the tools close to the wood, minimizing tool projection. A flat top to the rest hinders proper tool movement because there are two distinct pivot points when tilting the tool.

Grip

Many turners like to use an underhand grip to anchor the tool and improve control, so the shape of the rest should allow you to grip the underside with your fingers (though some sacrifice this for the sake of greater strength, and many turners prefer the overhand grip). The rest holder and locking levers must not obstruct tool movement, when the handle is low. For this reason, it is good to have alternative positions for the stem locking lever. The side of the rest that faces you should be steep, so the tool handle can drop low enough anywhere along the rest, including directly over the stem.

The lathe should have a short and a long rest as well as the standard, as all are useful. The long one may need a second rest holder. The rest should be capable of being positioned as close as possible to the lathe axis so tool projection on thin spindles is minimised, and should be easy to move. Some seem to fight back when being adjusted.

Tool rests can be replaced if necessary.

Weight

A heavy lathe shakes less when spinning an unbalanced piece of wood. Weight comes from strong and rigid cast iron/steel construction. The stand or bench that the machine sits on must also be strong and heavy,  but it may be possible to add weights to the stand to improve stability. The lathe will be more stable if it stands on a concrete floor.

Construction quality

Machines with strong and heavy components are usually OK. But there are some points worth checking when choosing a lathe.

  • Make sure that the spindle and motor pulleys have keys fitted into slots to secure them. Some makers rely on grub screws alone, which work loose and become a constant annoyance.
  • All-over machining of the pulleys will help them run smoothly, without vibration. Check that pulleys align properly.
  • Choosing a lathe with poor quality headstock spindle bearings, power switch, electronic variable speed controller and motor can lead to trouble later. Look for components of a recognised brand, not the cheapest that the maker could find. You want them fully enclosed to keep dust and chips out, and the motor fan cooled and rated to run continuously. Cheap motors run hot.
  • See that the top surface of the bed is smooth and true. A bed with a flat top may be easier if you want to fit accessories such as a steady rest. Be sure that the headstock and tail stock can line up accurately with each other. Any apparent error could be due to an uneven floor causing the bed to twist slightly, and easily corrected.
  • Make sure there is no detectable play in the tailstock ram when extended and locked. Also that the tailstock slides freely but locks immovably to the bed. The revolving tail centre must have no play in its bearings when under load (this is a replaceable item).
  • Make sure that the headstock spindle has no play or end float – fit the faceplate and see if it will move.
  • Make sure also that the tool rest holder and the tool rest itself move freely and lock immovably at all positions. Some will lock when close to the lathe axis but not when further out.
  • The screw threads that lock the toolrest and tailstock ram should be generous in size and snug-fitting. The points of the locking screws should not cut into the metal. The handles should be strong and preferably of steel, not plastic.
  • Poor paintwork and sharp edges on the castings suggest a lack of attention to detail at the factory.

Choosing a lathe for ease of use

It’s important to consider ergonomics when choosing a lathe. Good ones are designed for ease of use, and fit your particular needs. Look for spanner-free adjustments. See that the locking levers don’t get in the way (particularly the one that locks the toolrest stem – try it with the holder in different positions). Make sure that they are robust. Plastic levers will break in time. Levers adjustable for angle are useful. It should be easy to remove the tool rest holder from the lathe. Ideally this should be possible without removing the tailstock or dismantling anything.

If you are choosing a lathe primarily for making bowls and boxes, you may find it much better to be able to work from the front of the piece without having to bend over the lathe bed. A shortbed lathe, or one with a swivel or sliding headstock or with outboard turning provision lets you do this (though short bed lathes obviously sacrifice capacity, and you never know what lengths you may want to turn in future). But other turners are happy to work over the bed and don’t mind bending. A swivel or sliding headstock also prevents obstruction of the tools when the handles hit the lathe bed.

There should be an indexing arrangement for a swivel headstock so you can quickly return it to parallel. It is possible for debris to get under a swiveling or sliding headstock, affecting its rigidity and alignment. The tailstock could also be affected. I have not found this a problem in the lathes I have owned, but good design would minimise the risk. In particular, the headstock should not tilt when you loosen it. As long as it sits flat on the bed it will be difficult for chips to get between the metal surfaces.

When turning spindles, you will need to get close to the work. Make sure there is no obstruction to your feet that will force you to bend forward. If on a bench stand, the lathe should be well to the front, as consistent with stability. A gap underneath for your toes is good, though it will accumulate shavings.

The height of the lathe spindle is important if you use it for hours at a time. The usual rule is to have the axis at, or a little above elbow height. Then you don’t have to bend. But it depends on the individual. You may have to experiment to find the most comfortable height for you. Some lathe stands are adjustable for height. But it is normally possible to raise the lathe on blocks or to stand on a platform when working.

The headstock spindle and tailstock ram are best hollow. This allows you to use a knock out bar, and you can drill long holes on the lathe.  It’s nice if the tailstock taper is self-ejecting. An easy and effective spindle lock for the headstock is important so you can remove chucks. Provision for dividing is useful for some work. But the division holes should not double as the spindle lock, unless they and the locking pin are substantial. Otherwise the holes will soon wear.

A headstock handwheel that lets you turn the spindle is useful when inspecting  the work or winding on chucks. The tailstock handwheel should be generous in size and operate freely. A place to keep calipers, sandpaper etc is useful. There is often a flat top on the headstock for this. You also need somewhere to fix adjustable lights. But these aren’t necessarily on the lathe.

Unless you know you will not need to turn pieces bigger than the capacity over the bed, when choosing a lathe go for one with provision for outboard turning. Or one with a sliding or swivel headstock. You can use a freestanding tool rest, but they are often unsatisfactory. Unless they are rigidly locked to the lathe, they can tilt or bend inwards, causing a catch. Sliding headstocks and outboard toolrests may need more space in use. You need access to the ends of the bed and you may have to remove the tailstock. The tailstock cannot be used with a sliding headstock when it is moved right to the end of the bed. Nor when the headstock swivels.

Motor power

Choosing a lathe with insufficient power will slow you down. A 1/3 horsepower motor is about the minimum for a small lathe. It will do for small spindle work and for small bowls when cuts are light and work done slowly. Under-powered lathes stall easily, which is annoying. One horsepower will do for medium size bowls. It is enough for large ones if you use the low-speed pulley setting and take light cuts. Two to three horsepower will let you work at a natural pace on large pieces without stalling the motor. Large motors may need permanent wiring rather than just a domestic style plug and socket. Large motors are less safe for a beginner, because they can apply a lot of force to the tools.

Noise

The lathe itself should run quietly, though when cutting there will be more noise. You will soon tire of rattles and bearing noise. The lathe should have an induction motor, not one with brushes and gears. The drive belt should not be tensioned solely by the weight of the motor. This can cause it to bounce, which can lead to noise and vibration. To avoid this, there should be a lock for the motor. The motor should, ideally, be directly below the spindle to minimise shaking.

Speeds

When choosing a lathe, look for one with a good range of lathe speeds. Low speeds, preferably down to 200 rpm or less, are more important than high. This is because it is unsafe to spin unbalanced chunks of wood fast even on a heavy machine. If the wood is sound, balanced, secure and not too large, turning at higher speeds is usually best. But you will get used to whatever maximum speed your lathe has. Many lathes these days have electronic variable speed, and this is a great feature. Even more so if it goes down to zero and can reverse the lathe. The very low rpm you can get from a good variable speed unit can be useful. It helps if you want to apply finishes to work while it is still on the lathe or to sand green-turned bowls.

But step pulleys work well, provided that it is easy to adjust the speed. It should not be necessary to go behind or underneath the machine, unlock covers or use spanners. Even with good quality electronic variable speed, it is very useful to have step pulleys. This is because their lower speed settings give more torque. You can often upgrade a lathe to electronic variable speed, but at significant cost. Some lathes have mechanically variable speed, with lever-operated cone pulleys. I have little experience of these, but they are said to be unreliable unless well made and to cause rapid wear on the belt. The unit on the lathe at my turning club has not held up well. Adjustment is only possible when the lathe is running.

Accessories

Make sure the lathe is ready to accept headstock and tailstock accessories. Choosing a lathe with a non-standard spindle nose thread will make it hard to find chucks. Avoid machines that do not allow use of Morse taper fittings in both headstock and tailstock.

 

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