Lathe swing designation

[L98fiero]

I'm considering buying a new Multifix type tool post, it will likely be Chinese just from a cost standpoint, but they often come up with a size designation like 'Swing Over Bed C2/3 SC/2', how does that relate to the physical swing of my lathe. On any search I've done, if you replace the number, i.e., C2, C3, C4, ..... the physical size of the lathe doesn't seem to have much bearing on the number. I assume it's an ISO or Chinese standard but does anyone have an idea of how those designations work?

LaVerne

 

[Jasonb]

Those relate to Sieg lathes, have a look here for their size but basically 3.5" centre height or 7" swing depending on what part of the world you come from for the 2 and 3 which is the "minilathe" size, the 4 has 8" swing. It's a bit like saying the toolpost fits a Clausing, Atlas or myford

 

[H Pearce]

The swing of the lathe is not the most important aspect when selecting a qctp. The top of the compound to the centre is critical. Can the qctp go low enough to get your size tools on center? Or maybe like mine it needed a small spacer under to get the best usable and most secure clamping. Unfortunately most lathe manufacturers don’t list this dimension, not a problem if the lathe is already in your workshop but a bit harder if you are trying to order everything at the same time online.

 

[L98fiero]

The swing of the lathe is not the most important aspect when selecting a qctp. The top of the compound to the centre is critical. Can the qctp go low enough to get your size tools on center? Or maybe like mine it needed a small spacer under to get the best usable and most secure clamping. Unfortunately most lathe manufacturers don’t list this dimension, not a problem if the lathe is already in your workshop but a bit harder if you are trying to order everything at the same time online.

I have a 14 x 40 lathe, the set I need is the 'D' series, I was just trying to find out if the 'C' designation was a standard as most sellers don't list by swing, just by the series and the 'C' never had a reference to swing or even the physical size of the tool post.

 

[Beeblebrox]

Hi

This might help you.

From Chronos Ltd.UK

 

[L98fiero]

Now another question; boring bar holders.
Are there metric sized boring bar holders, I've looked and the bores are always imperial(inch) sizes but I can buy metric boring bars much cheaper than imperial sizes.

 

[Beeblebrox]

There is.

This is from Ali Express

 

[Steamchick]

The thing with boring bars, they cut a hole based on the lathe accuracy and tool setting. Not whether they are a metric or imperial bar. That is just an assembly feature. So my home-made bent metal, etc., boring bars are just as good as bought metric or imperial bars.... In fact they look like the toolmaker must have spent half of his life in boring bars.... (I.E. drinking!).
K2

 

[L98fiero]

Do you have a link?

The thing with boring bars, they cut a hole based on the lathe accuracy and tool setting. Not whether they are a metric or imperial bar. That is just an assembly feature. So my home-made bent metal, etc., boring bars are just as good as bought metric or imperial bars.... In fact they look like the toolmaker must have spent half of his life in boring bars.... (I.E. drinking!).
K2

While that's quite true, if you have a 20mm diameter boring bar it won't fit well(at all) in a boring bar holder with a 3/4 inch bore. You can just clamp them in a regular toolholder block but I prefer the holders that clamp around the bar like Beeblebrox showed as they provide much more support for the bar.

 

[Steamchick]

Understand. But That's not my tool. Mine is very small. The only time the bar is round is when the max metal is needed for stiffness in small bores. Mine is 5/16" dia. For use with the small 1/8" bit projecting maybe 1/16" I use it for boring 12mm and upwards. Bigger bars are square. Very small bars are square for mounting, ground to a round for the bore. For any length I always mount the tool to rotate and progress past the cutting pon't with a stationary component. It ensures a parallel bore. I use a long 3/4" dia bar with a fly cutter, mounted in a collet in the miller for cylinder bores of 1" dia.
I have come across v-clamps for mounting bound bars in the tool post of the lathe.
K2

 

[Richard Hed]

Understand. But That's not my tool. Mine is very small. The only time the bar is round is when the max metal is needed for stiffness in small bores. Mine is 5/16" dia. For use with the small 1/8" bit projecting maybe 1/16" I use it for boring 12mm and upwards. Bigger bars are square. Very small bars are square for mounting, ground to a round for the bore. For any length I always mount the tool to rotate and progress past the cutting pon't with a stationary component. It ensures a parallel bore. I use a long 3/4" dia bar with a fly cutter, mounted in a collet in the miller for cylinder bores of 1" dia.
I have come across v-clamps for mounting bound bars in the tool post of the lathe.
K2

What happened to you? did you get a camera?

 

[Steamchick]

Hi Richard, a bloke in work (years ago) caught me WORKING...! - Doing a water leak search on a car.... I.E. using a hose to piddle on the seals and check for leakage. Such scientific, highly technological methods are used to make cars! But it does seem like someone is taking the P###s to need a $100+/hour experienced and qualified Engineer to do a $20 per hour inspector's job....
That's why I vent my frustrations on this website!
Apologies to all.
K2

 

[Richard Hed]

Hi Richard, a bloke in work (years ago) caught me WORKING...! - Doing a water leak search on a car.... I.E. using a hose to piddle on the seals and check for leakage. Such scientific, highly technological methods are used to make cars! But it does seem like someone is taking the P###s to need a $100+/hour experienced and qualified Engineer to do a $20 per hour inspector's job....
That's why I vent my frustrations on this website!
Apologies to all.
K2

I see you posted a photo of your self.

 

[Steamchick]

Yup! It really is me, and Working! (hence the Hi-Vis Vest, as they often fall asleep in the test area, as the work was so exciting!) But many years ago... I was slimmer then, but more handsome now (apparently?).
K2