I'm looking to buy my first lathe and very tempted to go for the Sieg C3
however I'm stuggling to understand the lingo. Could someone please expalin
what 'Swing Over Bed' means?
Any reviews/comments/ regarding this lathe (preferably not from John
Stevenson as I feel they may be a little biased ^g^ )?
Swing over bed is the radius of the biggest part you can turn. But only over
the bed and not over the saddle. Here it will be less.
I ordered a new lathe this Monday. So I no longer qualify for
In article , Michael
Swing over bed means the diameter of an object which can be spun in the
lathe, i.e. twice the centre height of the lathe*. It seems to be of US
origin, and is a sneaky way for the marketing droids to make their goods
look more impressive.
*Actually, on thinking about it, I suppose on a lathe with split shears,
you could swing something a little more than twice the centre height,
determined by the shear separation - but this is splitting hairs as well
Swing over bed means double the centre height of the lathe.
It's more an American expression, we use centre height like 3-1/2" on
a Myford but the yanks have to go one better and call it a 7" lathe,
something to do with having the first floor on the ground and smaller
miles so they can go faster.
Technically swing over bed is slightly more than double centre height
as there is room between the ways to get a bit more in.
Not really relevant in these sizes but on a big lathe it can get you
the extra inch, or so Ower Gert reckons.
As regards non biased views and comments they must be equal to a
Myford as I can part one of these in two on the big 22" swing over bed
TOS just as easily as a Myford, does this help ?
Visit the new Model Engineering adverts page at:-
I have turned and parted 90 mm diameter in cast iron and mild steel at a
stretch, for turning, ie reducing the diameter of the workpiece. You have to
account for the saddle and the toolpost/toolholder.
You can go a bit larger, to maybe 170 mm, if you are only facing, ie
smoothing the end of the workpiece. You could probably turn a short piece
about 150 mm dia too, but it is not at all easy or convenient (or accurate).
For everyday work, imagine something that will fit in a tall (1 pint)
beercan - about that size is the maximum convenient. You can go larger, as
above, but it's a hassle.
I bought a Chester Conquest, the same design, and while I am reasonably
happy with it I do wish I had bought something larger. That's the best piece
of advice I have to give - furthermore either a new C6 or a used Myford 7,
super 7, or a Boxford A or B (don't get the C model) will be much more
rigid, and easier to use accurately once tuned up.
If you go for the C3 you should be prepared to do some work on it,
especially if is the unprepared version (I haven't seen a prepared one and
so can't comment), and to do some improvements - a lever-lock toolpost and
locks on all the slides are probably the most important.
You do know that tooling will cost at least half as much as the lathe, and
perhpas as much again if you want it really well-equipped?
Depends - aiui in the UK swing is usually the radius, in the US it's usually
Swing would be the radius, as you explained and would make sense. But then I
saw the picture and it was clear that they mean the diameter.
Thanks for explaining the ethnic differences in giving sizes. :-)
Center height is much clearer.
We use the same dimensions (center height, center length) or say diameter
over bed, over saddle or over bed gap.
I'm looking to turn a 160mm (OD) piece of PVC as the largest size,
everything else should be much smaller.
Seems it might be best to sit on the money and watch eBay and John's
Swing over bed is more normally the *diameter* that can be swung over
the bed, not the radius. The other measure used is center height,
which is the radius of the biggest part that you can swing.
If it's short, say an inch or so long, you might just turn 160 mm on a C3,
but any longer will be almost impossible. I say "almost" because people do
astonishing things with small lathes and big workpieces - but I couldn't do
it myself and don't know how it might be done.
You can face something that diameter quite easily though.
I have never worked with PVC, but I'd guess the C3 would be rigid enough for
good accuracy as the cutting forces will be low.
But I do recommend that you go for something bigger, if you can stretch the
budget that far and have enough room.
BTW I made a mistake earlier, the Boxford C/CUD is reasonably okay, it's the
T/TUD model you want to avoid (no screwcutting or longitudinal feed).