It's a bit obvious, but the fi rst thing a
woodturner needs is a lathe. It's actually
the world's oldest 'power tool' - see the
panel (left) for a bit of history. As you begin
to investigate what's available, you'll soon
discover that there's a bewildering choice of
models, with very different specifi cations
and prices, and it's very easy to become
confused about exactly what you require. If
this is your situation and you need some
help, then this feature highlights the main
factors you need to consider before you buy.
The lathe today
Woodturning has progressed enormously in
recent years and is now no longer just a
means of producing functional items, but is
fast approaching the status of an art form.
To fuel this massive increase in popularity
and demand, many woodworking machinery
manufacturers have hurriedly added lathes
to their range, but a good machine requires
a number of essential features that are
often overlooked in the rush to get new
equipment onto the market.
Cheap and cheerful
There are lots of very cheap lathes on the
market that all look the same and appear to
give you a lot for your money, photo 1.
These machines are very much entry-level
models, being suffi cient to get you started,
but if you progress much beyond very basic
work you will soon fi nd them very limited.
Some even come
with a stand and
incorporate variable speed, but there is a
defi nite correlation here between the price
you pay and the quality you get.
Weight is good
As a general rule, the heavier and more
substantial the machine, the better.
Vibration is the woodturner's worst enemy,
particularly if the workpiece is long or out
of balance, and there is nothing to beat
sheer weight to minimise this vibration.
For this reason, it's better to buy a lathe
that is cast rather than fabricated, but this
inevitably often involves greater cost.
However, do remember that unlike a lot of
other machines, you will often spend hours
working at the lathe. Consequently it needs
to be as smooth and quiet in operation as
possible, so always think carefully about the
quality and buy the best you can afford.
Photo 1. Cheap lathes appear to
give you a lot for your money
Photo 2. You need a distance
between centres of at least 30in…
Photo 3. …and a swing of at least
9in between spindle and bed
Bed and swing
When you are buying a lathe, there are two
capacities you need to consider. The
distance between centres determines the
maximum length of workpiece you can turn.
For general work you will need at least 30in,
and preferably 36in,
photo 2. Incidentally,
lathe dimensions are still mainly given in
imperial measurements; for metric buffs the
equivalents are 760 and 915mm. Longer
beds are available, and whilst these may
appear attractive, they can add to any
vibration problems unless they're properly
braced, so this is one instance where it is
better not to buy too much capacity unless
you have the specific need for it.
Another useful measurement of size is
the 'swing' of the lathe, photo 3. This is the
height of the main spindle above the bed
and therefore determines the maximum
diameter of work you can turn, unless the
head rotates round. For anything remotely
approaching serious work, you need a swing
of at least 9in (230mm), but in practice the
bigger the better.
Bench or floor mounted?
A professional turner will probably need a
heavy-duty floor-standing lathe, but for the
home woodturning enthusiast a bench-mounted
model will probably be quite
sufficient, photo 4. These bolt down to any
convenient work surface, but this must be
really solid. The advantage of mounting it
on your own workbench is that you can get
the centre height just right - a serious
consideration if you anticipate doing a lot of
turning in the future.
Photo 4. A bench-mounted model
like this will suit most woodturning beginners
Stands and storage
Several manufacturers provide leg-stands as
an optional extra if you don't want to build a
bench. These stands vary from a rather
crude folded steel or tube arrangement, to a
more rigid affair with provision for a tool
shelf, photo 5. Bear in mind that the
performance of your lathe depends on how
well it is mounted, so buy a leg-stand only if
it looks man enough for the job.
Photo 5. Some more rigid leg-stands
include provision for a tool shelf
Photo 6. Under-bench storage helps
to give a stand useful extra mass
A homemade wooden bench is often
better at absorbing vibration than a crude
metal stand, and it can change the whole
operation of the lathe. If you are short of
space in the workshop, you can build in a
lot of storage for tools or raw materials
under the lathe, which also helps to give
the structure a bit more mass, photo 6.
The lathe bed
The bed is made from either heavy metal
bars or tubes,
photo 7, but some machines
still feature a flat cast bed. This may be
quite crude on the cheaper machines, or a
work of art on top-of the-range models,
photo 8.
Whatever the construction, it must be
strong enough to support both the tailstock
and the tool-rest without any flexing, and
allow free and easy movement of them
both. It must also permit shavings to fall
through unobstructed and should sit well
clear of the bench, so you can slide the
tools underneath it without banging the
sharpened edges.
Photo 7. The lathe bed is made
from heavy metal bars or tubes
Photo 8. More expensive beds are solid
castings that are almost a work of art
Photo 9. Some imported models have
what looks like a huge headstock
Photo 10. The bearings should be
good quality heavy-duty ball races
Photo 11. Tapered bronze-sleeved bearings
give greater support than ball races
Photo 12. The headstock may have the
facility to swing round through 90°
Photo 13. Swinging the head off-centre
keeps tool handles clear of the bed
Photo 14. You need an additional tool rest
for turning big-diameter bowls
Photo 15. A headstock you can
move along the bed is a big advantage
Photo 16. A spindle thread size of
¾in x 16 tpi is the industry standard
The headstock
This is the heart of the machine and needs
to be really solid, and preferably cast.
Fabricated headstocks are rarely heavy
enough if you need to turn large or
out-of-balance work. The headstock also
needs to have a good spread between the
bearings to ensure maximum rigidity of the
spindle.
Some imported models have what looks
like a huge headstock, , photo 9, but when
you remove the belt cover the two spindle
bearings are actually quite close together. A
small bearing spread like this will causes
problems with rigidity, particularly on large
diameter work, so always look for a machine
where there is plenty of distance between
the bearings.
The bearings themselves should be good
quality heavy-duty sealed ball races, photo
10. Some machines have a tapered bronze
sleeved bearing which gives much greater
support than ball races, although it does
require occasional adjustment. However,
when set up correctly this arrangement
supports the spindle over a much greater
length and provides totally smooth and
vibration-free running, photo 11.
A swinging head
The headstock may be permanently fixed in
line with the bed, or it may have the facility
to swing round so that the spindle ends up
at right angles to the bed for bowl turning,
photo 12.
I would rate this swinging head as an
essential feature on a lathe; the real
advantage is not only for bowl turning, but
also for any turning where you have to work
over the bed. Swinging the head just a few
degrees off-centre allows you to work with
the tool handles clear of the bed, photo
13. Although you can still work off the
standard tool-rest with the head swung a
little, for big diameter bowl turning you will
need an additional bowl rest to maximize
the capacity, photo 14.
If you are restricted with regards to
space, many of the swinging head machines
also allow you to move the headstock bodily
along the bed, which is a great advantage if
the end of the machine has to be up against
a wall, photo 15.
The spindle is key
The headstock spindle is threaded to take a
range of screw-on accessories such as
chucks,
photo 16, so you need one with a
standard thread or you'll be limited in the
range of extras you can buy. On many
smaller lathes, a thread size of ¾in x 16 tpi
is the industry standard, which makes
upgrading your machine less costly.
This which means that you can then take
all your threaded accessories with you,
rather than renewing them with the lathe
when you upgrade it. This is an important
point, as you will often have a substantial
investment tied up in chucks and other
accessories.
Morse tapers
It is essential that your lathe is also
equipped with Morse tapers in both
headstock and tailstock. This is a universal
means of installing centres and a range of
other tooling,
photo 17, and does not
restrict you to using only the original
manufacturer's fittings.
There is a huge range of Morse taper kit
on the market, but if you buy a lathe with
only screw-on fittings you are very restricted
as to what you can use. Morse tapers are
commonly No 1 or No 2 on the smaller
lathes; the bigger the number the thicker
the taper. The tapers just push into the
headstock and are then knocked out
afterwards with a bar that runs through the
main spindle.
If the spindle is solid, there needs to be a
centre ejector which screws onto the
spindle nose before you insert the taper,
photo 18. Take great with these tapers and
keep them clean and undamaged, or they
will start spinning inside each other, which
as well as causing them damage, will lead to
inaccuracies when you are using fittings
such as drill chucks.
Photo 17. Morse tapers are a universal means of installing centres
Photo 18. A solid spindle needs a centre ejector screwed onto the spindle nose
Photo 19. A three-or four-step pulley gives a speed range of 400-2000rpm
Photo 20. Some lathes use cone
pulleys to change the lathe speed
Photo 21. Modern electronic control
offers infinite variation of speed
Photo 22. Memory functions can
remember your favourite speed settings
Motor and drive
A small lathe will need a motor of at least
1⁄3hp, particularly if you envisage turning
bowls, but bigger is better in this case. In
order to give some speed variation, the
motor is usually fitted with a three or
four-step pulley and a matching one on the
spindle,
photo 19, to give a speed range
from about 400 to 2000 rpm. This is
achieved with a belt, which is moved
around on the pulleys to select the required
speed. The traditional V belt has now
virtually been replaced with the more
efficient fl at poly V type, which gives a
smoother, vibration free drive as it has no
lumpy joint.
Some lathes achieve the speed variation
in other ways. This may be mechanical,
where a lever operates two cone pulleys, so
changing their diameter and therefore the
speed, photo 20. This system does work,
but it is prone to wear belts very quickly
and is rather noisy. Also, you can only
change the speed whilst the lathe is
running. So if you finished the last job at
top speed and now want bottom, you firstly
have to switch the lathe on and reduce the
speed before you can mount the work, all of
which is a bit fiddly and time consuming.
Electronic controls
The ultimate for speed changing is an
electrical speed control, which gives you
infinite variation of speed at the turn of a
knob. This is usually reserved for the top-of-the-
range lathes, but in the past electronic
speed variation has suffered from loss of
torque at low speeds. Fortunately modern
electronic technology has largely overcome
this problem, usually by operating a
three-phase motor through an inverter off a
single phase supply,
photo 21.
State-of-the-art electronic speed controls
have memory functions that can remember a
selection of favourite speeds. They can also
sense incidents such as dig-ins and then
instantly shut down the power, photo 22.
Photo 23. A magnetic switchbox can
be fixed wherever you're working
Photo 24. The tailstock barrel needs
plenty of travel for drilling work…
Photo 25. …and should be drilled
through to allow for long hole boring
Photo 26. A cam lock on the tool rest
is easily accessible from the front
Photo 27. Tool-rests are available
in a range of different lengths
Easy-reach switchgear
Whatever your motor type, make sure that
the switchgear is easily accessible and
doesn't get hidden by large workpieces. I
prefer to have the switch (or at least a
separate 'off ' button) at knee height for
emergency situations when you have both
hands full. Some machines have a magnetic
switch-box, photo 23, which allows you to
move it around at will depending where you
are working.
Reverse gear
Motors with a reverse facility are a valuable
aid for sanding, and are quite safe to use on
between-centres work. However, if you
engage reverse with a piece of faceplate
work, there is always the possibility that it
will unscrew itself, so lathes with reverse
should feature a faceplate locking system.
The tailstock
This needs to be as substantial as the rest of
the lathe, as it has to provide fi rm support
for between-centres work. Make sure that it
slides freely and locks firmly onto the bed.
The tailstock barrel is moved backwards
and forwards with the hand-wheel and needs
plenty of travel for drilling work, photo 24.
It should be bored with a Morse taper to
match the headstock, and should also be
drilled right through to allow for easy
removal of the tailstock centres and for long
hole boring, photo 25.
Tool-rest and slide
The tool-rest assembly is another vital part
of the lathe, the main requirement being
that it is quickly and easily adjustable. The
actual locking mechanism varies from
machine to machine; some use a simple
clamp and lever under the bed, whilst
others use a cam type of lock,
photo 26,
which is easier to use as it is accessed from
the front of the lathe. Always check this
point before you buy.
The tool-rest itself needs some vertical
height adjustment and should lock into the
holder with a simple handle that works
effectively; there must be no movement
possible once it's locked. For general use
the rest needs to be about 10in (300mm)
long, and made of heavy cast construction
so that there's no vibration when you are
working at the end of it.
Alternative length rests are available,
photo 27. You will probably need a shorter
one at some stage. For very long work there
is a rest with two stems, but this requires an
additional tool-rest holder.
Look out for part 2
where Alan introduces the basic woodturning
tool kit, and explains how to separate
the wheat from the chaff
Making a choice
So now you know all about the lathe, how
do you choose one to suit your needs?
Firstly, consider the type of turning you
will be doing. If you will mostly be turning
spindles, then there's perhaps no need for a
swinging head model, but rigidity of the bed
and good between-centres capacity are
important features.
On the other hand, if you think your main
interest will be bowl turning, a swiveling
head is vital but between-centres capacity is
less important. You'll also need plenty of
motor power for big-diameter bowls.
If you want to do a bit of everything, try
to decide on the biggest diameter you want
to turn and choose a lathe accordingly.
Think also about how often you will use
the machine. If you anticipate being an
occasional user making a few simple
furniture parts, then a basic model is all
you'll need. But if you think you will spend
a lot of time at the lathe as your skills and
ambitions grow, then you will need the extra
power and weight of a larger machine.
As you go further up the range you will
find this extra power and solidity allows you
to turn more quickly and confidently. You
can take deeper and more ambitious cuts,
and the ease of use of features such as
electronic variable speed control make
turning more intuitive and enjoyable.
Above all, bear in mind that woodturning
is an addictive hobby, so try to buy in as
much spare capacity as you can afford now
to save expensive upgrades later on.
sparky
