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There are times when you need to build a table,
a hall stand, repair or replace a leg, make some birthday or
xmas gifts, or make multiple copies
of an item on a lathe. While you can just make multiple copies
by hand, the process can be time consuming, and unless you are
an expert woodturner, chances are that all copies will not be
exactly identical. This is where a lathe copy attachment comes
into play. Some may call it 'taking the easy way out', but I
think they have a place in woodworking, and they can certainly
be time, and frustration-saving devices. On the menu today is
the Sherwood SCA-900 Lathe Copying Attachment... I think we
will indulge ourselves in a review!
Out of the Box
The first question that should be raised, even before you
think about buying this is; "Will it fit my lathe?" In most
cases, the answer will be yes. The SCA-900 is designed to fit
any cast bed or twin bar lathe with a center height of
125-300mm (around 5-12 inches). I have an MC-900 wood lathe
with a cast iron bed, and the lathe copy attachment fits this
model just fine without any major modification.
The SCA-900 ships somewhat unassembled, so some
assembly is required before you can attach it to your lathe.
The instructions are not the best I have seen, but you can get by ok if
you take your time, don't try to rush, lay out all the parts
and screws/nuts etc before you begin and take it one step at a
time. It took me roughly thirty minutes to put it all
together, and another 5 minutes or so to attach it to my
lathe. If you have a second person on hand to help, it makes
the task easier. I got by fine on my own. The copy attachment
itself is not overly heavy, but can be a little awkward to
hold while securing it down.
Once it is installed on the lathe you can get
a better understanding of how everything works, and you should
play around with the adjustment features so you become
familiar with the device before you start attacking those rare
wood blanks. Essentially, the copying attachment will allow
you to make copies of spindle type pieces. This includes
everything from turned table legs to baseball bats! Naturally,
this attachment cannot duplicate the inside of bowls, turned boxes
etc.
You can also make up your own templates from
thin sheet material like MDF or ply if you wish and use those.
How it works
You mount either your original turned piece to be copied,
a sample piece you wish to copy, or your pre-made profile template into the
lower section of the lathe. Adjustable stationary centers hold
turned items securely on both ends, or small template pattern
clamps hold your template underneath (there are three provided
and they can be located at various intervals along the lower
copy attachment frame).
A guide rod sits
underneath the main carriage assembly and this rides against
the edge of the template, or against your original turning. I guess its more accurate to say
that it actually stops the cutter above cutting in too far or
presets the depth stop point for any part of the template or
turned object along its length. Any movement in this bottom
guide rod effects an equal movement at the cutter tip above,
so as you make successively deeper passes and slowly move the
guide rod in closer to the template or sample turned piece,
the cutter above cuts successively deeper as well.
The bottom guide rod has a spring loaded attachment to the
main carriage, so it can ride around curves and into coves to
make a quality reproduction.
Speaking of the cutter tip, this is located on the upper guide
carriage, and is essentially a sharp-tipped diamond shaped
'chisel'. Some other branded models may ship with the
standard hardened steel tip, however, the Sherwood model ships
with the upgraded tungsten carbide cutter for added durability
and longer cutting life. This comes at no extra cost to the
purchaser, which is certainly a welcome, and free addition!
The cutter tip is reversible, so you can use both ends as
well.
So on a new copy procedure, you set your guide
rod up on the outermost section of the template or copy piece
(i.e. the widest part), lock the depth there and turn the
wheel on the carriage to move it along its rail left or right.
I found it is much easier to use the SCA900 when you rough
turn your blank down to round to begin with. Furthermore, if
you turn it down round to the diameter of the widest point of
the original, or the pattern, you will make your task even
easier. This results in a properly balanced blank, and there
is far less vibration in the lathe and tool in use than when
trying to turn down a square blank to round (trust me, I tried
both!). Also, ensure the cutter tip is retracted back as far
as possible once set to the widest diameter on the template so
you have plenty of forward cutter movement range to work with.
As the carriage and cutter tip move, it 'turns' off a shallow layer of material.
It can give a rough result, depending on the wood used. Pine
and other softwoods tend to chip out quite badly, so its a
good idea to make relief cuts on any square edges of a turning
to avoid this problem. Once
you reach the end of the rail, set it a little deeper and
start winding the carriage back in the opposite direction, and
hence, taking more material off the blank. Depending on your
template or the complexity of the turned piece, you may need
to turn your item in sections, or work the widest diameter
sections as a group before turning down to the thinner
sections. You continue this
process, and work your way around the various coves, tapers
and beads etc in the piece. The spring loaded guide rod
underneath guides the cutter around profiles as you go. It's a
good idea not to take off too much material in one pass. That
will prematurely blunt the cutter tip and results in a rougher
finish. There is a hand steady handle that
can directly control the depth of the TCT cutter up top, and
this is useful if you need to plunge the cutter into a section
before guiding with the hand wheel laterally. This guide handle
can also be set to stop at a set depth via the cut depth
adjustment wheel it is attached too. Additionally, I found
using the handle allows more controlled turning, especially
around tighter profiles.
There are metal 'sleeves' around the guide rod
underneath which help it to roll over the template, however,
for finer work, these sleeves are a little thick. They can be
removed easily to leave you with a thinner rod to get into
tighter places, however, this thinner rod (which is actually
the underlying screw - non-threaded shaft) is a little harder
to roll around curves and across surfaces, so more care is
required by the user.
The whole process can take a good length of
time the first few times you use the attachment. It may well take several hours to turn out 4 or so legs
for a table, so its not a production device that is going to
give you results within minutes, although it really depends
largely on the size/diameter of the blank, and how much
material you need to remove from it. Patience is required,
with the end result being perfect duplicate legs, or whatever
other item it is that you are turning, and certainly better
reproductions than you could do by hand, well with me at
least. I'm not the world's best turner, so being able to
duplicate a set of turned items is extremely useful in
creating furniture or items that actually looks symmetrical!
While you lose that added 'handcrafted' touch when you use
such a device as a copy attachment, you have still put in the
effort and hard work to make the original (if that is the
case) and the copies, and no one can take that away from you.
I found the satisfaction factor to remain very high in use.
You certainly still end up with the same amount of mess on the
floor as you do when hand turning.
Once your item is turned down, you need to sand
it down to a smooth surface. I used 120 grit to start off,
then 240 grit and finished with 320. Depending on the item, I
sometimes sanded to a finer grade to give the surface finish
desired.
Adjustment Features
The SCA-900 itself is adjustable to suit many types of
lathes, and can be adjusted to handle different sized
projects. For example, you can adjust the height of the cutter
tip via the adjustable height pillars on both ends of the
lathe, effectively raising (or lowering) the height of the entire copy
attachment. This is achieved via basic clamp-type screw knobs.
To be honest, it's not the world's easiest height changing design,
and it can be a little tricky to adjust at times, however, you only need to set it once for
each particular task, and that point is roughly at the
midpoint of the blank's height/diameter.
You will also need to set up the width between
the 'center' posts if you are copying an existing turning. I
got caught out on my first attempt by not providing enough
clearance either end for the carriage to travel right to the
ends of my blank. The centers and end posts can be adjusted
with a little screw work. A 3/8" spanner will do the job.
Depending on your lathe, and the length of the project, you
may also have to adjust the clamps holding the copy attachment
to the lathe itself. I have a generic MC900 lathe, and I found
I needed to add about 5 washers to each clamp under the base
to ensure the clamp heads actually made contact with the
bottom of the lathe bed to clamp it securely. No major drama.
Practice Makes Perfect
Familiarizing yourself with the SCA900 copy attachment
before you turn expensive wood is recommended. The attachment
itself is not overly complicated to operate, in fact, it is
extremely easy, however, if you understand the basic
principles of how it works, and what adjustment features give
direct control over the cutter tip, you will minimize any
'first use' errors. I found that after I successfully
completed my first copy of a leg, I had learnt all I needed to
know to master this machine, it's that simple. My wife now
uses it with equal success as well.
I found that on some more intricate patterns,
you may need to finish off the finer sections with a little
hand turning work because the guide rod just couldn't get into
those small grooves effectively. This is not really a problem
in my opinion. I'd rather be left with that small task (which
was mostly small flat sections finish with a parting tool)
than trying to mark out and duplicate 6 legs to close
tolerances from scratch by hand! Also, because the cutter is
essentially just a sharp tip, a bit of finishing sanding work
is required to smooth everything out. Again, a task I am happy
to complete knowing I have just turned exact duplicates very
easily. A skilled turner could probably certainly turn down 4
legs faster than I could do it with the SCA-900 copy
attachment. I'm no expert woodturner, but with the SCA-900 you
could easily be tricked into thinking I was! It seemingly
gives you the skills of an experienced woodturner, even if you
have no woodturning experience at all.
Conclusion
The SCA-900 will not mass produce turnings in record
times. It can take a few hours to turn out a set of table legs
(depends on diameter of course), however, if you are not an
expert turner, or have never even turned before, you can make
exact copies of those table legs, bed or furniture spindles,
some pen styles, even baseball bats with relative ease. The
other big advantage of the SCA-900 and similar copy
attachments is that they can replicate custom pieces that are
not readily available in hardware or woodworking stores.
Consider a table with turned legs where one leg needs to be
replaced. Chances are you cannot buy a replacement leg from
anywhere locally, or even at all, however, with a lathe and
the SCA-900, you can make your very own replacement, probably
at a much cheaper price than it would cost to have a
woodworker or woodworking shop create the custom item for you.
The SCA-900 is also great fun to use. I'm certainly planning
to now add more decorative and functional turned items to my
future woodworking projects, as well as to turn out a couple
baseball bats for my son and other young lads in the extended
family for Christmas and birthday presents.
The Sherwood SCA-900 retails for just
AUD$159... Yes, you read right. At well under $200, the copy
attachment is almost a steal and certainly worth the money
considering how much you can save on buying pre-turned or
custom turnings from a retailer. I was quite happy with the
performance of the SCA-900. While some adjustments take a
little 'work', on the whole, the copy attachment performed its
intended task extremely well, and in the end, that is what
counts the most to me!
The Sherwood SCA-900 is sold by Timbecon in
Western Australia. It can be ordered via their website at
www.timbecon.com.au
or by phone (phone number available on their website).
Note that similar copy attachments/duplicators
are available around the world and made/sold by various
manufacturers (for our USA/Canadian and International
readers). You can order this item online
in Australia from:
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SCA-900
Photos
All photos copyright onlinetoolreviews.com. Use without prior
written permission prohibited
The SCA-900 assembled and fitted to the lathe.
The hand wheel moves the carriage along the rail left and right.
The diamond shaped TCT cutter comes standard on the SCA-900!
Template clamps
Note the black 'centre' in the middle of picture to clamp existing
turned items securely.
The clamps holding the copy attachment to the lathe bed.
The guide rod extends down beneath the main carriage.
Ready to copy! The original mounted below, the blank loaded up top.
Making a copy. Note some of the lower leg profile is already starting
to take shape on the top blank.
And here's our copied piece...
The original, and the copy (after sanding). I had to hand-finish the
finer details, but otherwise, pretty much a perfect match!
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