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:-
Perhaps you know the 7x12 newsgroup for the mini-lathe owners (swing over
bed x distance between centres in inches - sorry, not everyone knows!) well,
there's also an ng for the newer Sieg C0 - and the control panel seems to be
a bit of an issue with Sieg- not sure if it was mentioned here before - many
other brands have incorporated a US circuit board as they are more reliable.
Check out a regular poster by the name of Uncle Rabid - he spends his time
repairing them as well as offering advice. They're good machines
nevertheless, or I wouldn't be buying them.
Good luck with whatever you choose in the end,
ps I'll also have cnc converted machines before long! sorry for the plug.
Hi Michael - are you the guy that was building the model submarine a while
back? Sounds like yuo are still looking to turn large diameters in PVC.
Interested to know how the submarine build went if it was you -
One technique you seem to have missed for larger fibreglass one-off
constructions is to build the former out of blue extruded polystyreen
foam and cover the foam with glass and resin, then dissolve out the foam
once the resin is set - much easier than using plaster and release agents.
 or even a dense white expanded ps foam, _much_ cheaper if you don't need
fine fairings and an unblemished inner surface :)
 I use a little cellulose thinners to start, then use 100% isopropyl
alcohol (the 90% IPA sold as rubbing alcohol doesn't work nearly as well) to
remove the still-wet goo. You can also use styrene, also sold by most
No I havn't missed it, I just find working with plaster much easier as I
find it works well as a 'backup' should I miss a bit with mould
release/sealer and provides a much firmer surface to work with when I'm
fibreglassing it. I'm also going to be building two both with different end
results in mind.
But even so, in theory you don't even need to dissolve it. As I'm making it
in sections I should just be able to lift off the fibreglass (though
obviously a little compressed air/solvent of some description would make it
alot easier) as it is essentially a cone shape.
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