# X, Y, Z On A Lathe



## Tozguy

Is the following a fair statement?:

'The axis parallel to the spindle axis is always Z, whether its a mill or lathe. And, for the lathe, the axis that controls the diameter is always X.''

Does that mean the 'up and down' adjustment when using a milling attachment on the lathe is the Y axis?


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## Terrywerm

The statement is correct, and I would tend to agree that your assumption about 'Y' is correct also.


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## higgite

Yes. On a lathe, carriage travel is Z, cross slide travel is X and tool height adjustment is Y.

Tom


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## jmarkwolf

higgite said:


> Yes. On a lathe, carriage travel is Z, cross slide travel is X and tool height adjustment is Y.
> 
> Tom



Then what's the compound axis?


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## higgite

The compound isn't restricted to a single axis. Maybe that's why it's called a compound? 

Tom


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## Tozguy

To my mind the compound rotates on an axis but what to call it? Bet the CNC guys that write 5 axis programs could tell us.


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## atunguyd

Tozguy said:


> To my mind the compound rotates on an axis but what to call it? Bet the CNC guys that write 5 axis programs could tell us.


With CNC there would be no need for the compound. The use of Z and X in tandem can achieve everything that the compound can do and more. 

Sent from my SM-N920C using Tapatalk


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## Tony Wells

In standard convention, if memory serves, the basic axes are X, Y, and Z with the additional axes identified by number. On a mill, or HMC/VMC, the primary rotary axis is called the 4th axis, and if the mill spindle articulates, you gain another, and if the rotary axis in mounted on  trunion table, you gain yet another. Sub spindles and live tooling on lathes and powered tailstocks just keep adding.  Plus the main spindle can be used with a control as an axis of its own. I've not been around anything with more than 7 that I can remember, and that was at a Halliburton internal shop. I really don't know what the limit is. Never thought about it or talked with anyone about it. Not long after that project we took from HES's shop, we bought a similar machine. Theirs was a Integrex of some series. Been too long. I know we sent a couple of guys for a couple of weeks of training on a 7 axis(I believe) machine once. Machine was over a million and the software to program is came to around 100k for 2 1/2 seats. Very sweet machine. I have some pictures somewhere, but with about 70,000 in my collection they would be hard to find. They aren't organized well.


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## Tozguy

Seems we ran out of letters too quick by starting with x. What were those trig guys thinking?  I just developed a splitting headache. In my shop until further notice we are sticking with letters and the rotational axis of the compound is to be called the C axis. Not to be confused with compound travel. If you want to discuss it come on over. Bring donuts and I'll brew some gourmet coffee.


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## British Steel

Don't quote me on it, but the usual axes are X-Y-Z and A-B-C, as I understand it A, B and C are rotations around X, Y and Z so a rotary table on a vertical mill would be C-axis, a dividing head set up for gear cutting would be A-axis - but I may be wrong, it has been known (ask my ex...)
That would make topslide *rotation* B-axis, damned if I know what topslide travel would be, combination of X and Z, lots of sines and cosines involved?

Dave H. (the other one)


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## higgite

Tozguy said:


> To my mind the compound rotates on an axis but what to call it? Bet the CNC guys that write 5 axis programs could tell us.



I'm going with definition no. 5 for axis as it applies to a lathe or mill.
http://www.merriam-webster.com/dictionary/axis
5:  a main line of direction, motion, growth, or extension.

A compound has no _main_ line of direction, etc.,, therefore, no single axis to be numbered, lettered or named. That's my story and I'm sticking to it. 

Tom


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## JimDawson

I just make it up as I go along.  My mill has X, Y, Z, K(nee), and R(otary) on the DRO   Keeps me from getting confused, I don't care about the rest of the world!


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## Tozguy

Almost proves the old saying that there are as many realities as there are persons on the planet.
Tony knows of at least 7 axises so maybe we should name one the T axis after him.
Atunguyd, I simply cannot live with only 2 axises. My compound would tremble at the thought and it shakes enough already. 
Tom, you are right about the compound not having a linear axis and that is why we should lend it one.
Dave, are you one of the guys that solved the enigma?
Time for my nap, Mike


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## epanzella

I always called my vertical axis when milling in the lathe my Z axis. I know this flies in the face of the definitions but to do otherwise means any lathe sold without a milling attachment only has an X and a Z axis, but no Y axis. Unless you call tool height the Y axis but being as it doesn't move while machining, I don't see that as an axis any more than putting parallels under a part in a mill vice is a new axis.


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## John Hasler

epanzella said:


> I always called my vertical axis when milling in the lathe my Z axis.


As soon as you rig your lathe as a mill it becomes a mill and you can use milling conventions.


> I know this flies in the face of the definitions but to do otherwise means any lathe sold without a milling attachment only has an X and a Z axis, but no Y axis.


Sure.  What's wrong with that?


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## planeflyer21

When working on Fadals, the CNC axes were as such:

X-to and away from the operator.
Y-right and left of the operator.
Z-up and down of the spindle.

A-always a rotary table, always mounted parallel to Y and perpendicular to X and Z, the rotation being similar to that on a lathe and controlling what surface was engaged with the cutting tool on the Z.
B-mount the A-axis rotary table on a mechanically tilting angle plate, with a range from 0° to 90°.  Here is where you really start to see very complex parts from one piece of metal stock.
C-take the B-axis and mount it on a rotary table.  A lack of imagination is the only limitation.

We had one part we ran on a 5-axis (XYZ AB) Fadal that was a 17-hour operation, an impeller from aluminum billet.  Something like 24 scimitar-shaped blades, tapered from hub to blade tip, tapered from leading edge to trailing edge, wtih a compound curve on both the leading and trailing edges of each blade.

I've no idea what the company charged for those parts but they were never left unattended, even though we had only 1st and 2nd shifts.


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## Tony Wells

Not uncommon for shops who do 5+ axis work for $200/hr around here. Pretty cool to watch the first few times. 

After we got our programmers back from school, they showed a project they did at the school. (I won't name the software...it's pointless here) I thought it was cool, even though it was very simple. I just had not thought any machine had the capability to do it until I put the pieces together. They made themselves a nice _hexagonal_ pen. I saw the video of it, or I may have not believed it at first. It involved live tooling with a 6 inserted face mill, and with the chuck spinning around 1k, the encoders for both the spindle and the like tooling were synched up so that as the insert swept by the pen, it produced a flat surfacing cut. I know they could have simply indexed the spindle and milled the flats, but they did all the cutting with both the spindle and the live head rotating, but timed perfectly. Besides, the live spindle was on an axis parallel to the spindle, so the only possible tool motion was purely circular. I never could get them to make me one on the machine we had on the floor, but it was capable. There's probably a video on youtube showing something similar. It could have been triangular, square or any other regular polygon I suppose.


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## Chipper5783

Tozguy's original questions was with respect to using a mill attachement on a lathe.  Per his supplied photograph, my own lathe/mill attachement and any other that I have seen (though I'm sure there are exceptions) - the compound is not used.  The discussion about what axis the compound is, though interesting - isn't relevant to the OP's question.

The OP has repurposed the compound as the y-axis slide (as Terry has already pointed out).


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## Tony Wells

In reality, in the hobby environment, it matters little what you call them, as long as you get the parts made that you want. On a manual machine, the operator determines what part of the machine moves to make a particular cut, and it doesn't even need a name.


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## Tozguy

My original objective was to identify and adopt conventional terminology when making notes about my machining exercises on a lathe. I keep a log book of the stuff done, what worked, what didn't, and why (when possible). Helps me digest and learn from it. Just thought that referring to the x,y, or z axis would be a new level of sophistication for me 
Thanks everybody for the input.


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## astjp2

There is several standards that cover this topic, asme and an ISO one from what I remember.  Tim


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## British Steel

Tozguy said:


> Almost proves the old saying that there are as many realities as there are persons on the planet.
> Tony knows of at least 7 axises so maybe we should name one the T axis after him.
> 
> Dave, are you one of the guys that solved the enigma?
> Time for my nap, Mike



Nope, but Alan Turing worked where I work now... 
And Donald Davies (packet switching, you know, how the internet works)
And Sir Robert Watson-Watt (RADAR)

I'm just a humble engineer though, not a high-browed scientist 

Dave H. (the other one)

Edit: Forgot Louis Essen, atomic clock maker, should remember him, it's what I'm messing with!


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## Wreck™Wreck

planeflyer21 said:


> When working on Fadals, the CNC axes were as such:
> 
> X-to and away from the operator.
> Y-right and left of the operator.
> Z-up and down of the spindle.



We have a 20 X 40 two and a half axis Fadal mill, it also has a 4th axis that simply moves the coolant nozzle in a relationship with the tool in use IF you enable it and IF you are willing to program it, I believe that Fadal calls this feature "Servo Coolant".


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## Tozguy

British Steel said:


> I'm just a humble engineer though, not a high-browed scientist
> 
> Dave H. (the other one)
> 
> Edit: Forgot Louis Essen, atomic clock maker, should remember him, it's what I'm messing with!



Yikes, are your posts radioactive?


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## Tozguy

astjp2 said:


> There is several standards that cover this topic, asme and an ISO one from what I remember.  Tim



Good thing you didn't remember them all, they would just get in the way.


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## Tozguy

Wreck™Wreck said:


> We have a 20 X 40 two and a half axis Fadal mill, it also has a 4th axis that simply moves the coolant nozzle in a relationship with the tool in use IF you enable it and IF you are willing to program it, I believe that Fadal calls this feature "Servo Coolant".



A two and a half axis mill that has 4 axises and a programmable coolant nozzle, boy you really know how to wreck a thread.


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## British Steel

Tozguy said:


> Yikes, are your posts radioactive?



Other kind of atomic! They use a Caesium vapour and pump it with the atoms' ionisation energy/frequency, which is re-emitted when it returns to neutral - it's incredibly stable and a single frequency which is then counted down to once-a-second.
The Best Clocks in use are accurate to about a second in 158 million years, the next generation are getting difficult to measure, as they're in the one second in the lifetime-of-the-universe bracket...
I just distribute the time from 'em, accurate to a ten-millionth of a second everywhere it reaches, the easy bit.

Dave H. (the other one)


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## benmychree

Tozguy said:


> My original objective was to identify and adopt conventional terminology when making notes about my machining exercises on a lathe. I keep a log book of the stuff done, what worked, what didn't, and why (when possible). Helps me digest and learn from it. Just thought that referring to the x,y, or z axis would be a new level of sophistication for me
> Thanks everybody for the input.


I think life was wonderful as a machinist before all this XYZ crap was invented; I'm talking the early 1960s, when we had longnitudinal, cross feed, and little else; on mills, we had table feed, infeed and vertical feed; call me an old fart; guilty!


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## astjp2

Tozguy said:


> Good thing you didn't remember them all, they would just get in the way.


Try this on for size, AME
http://manufacturing.stanford.edu/processes/Turning&LatheBasics.pdf


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## JohnBDownunder

Oh Dear, Just to confuse things even more perhaps.
      Being one who messed about in boats I referred to the "Y" axis on my mill as the "Port n Starboard" the "X" as "Fore n Aft".  The "Z" was just "Up n Down".  Still do at times. 
       It depends on what terms you are used to I guess.  But, when talking to other swarf nuts it is best to learn the conventions and I am still trying. 
John B

ps. Just had a look at the Turning&LatheBasics.PDF now me ed aches.


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## Tozguy

British Steel said:


> Other kind of atomic! They use a Caesium vapour and pump it with the atoms' ionisation energy/frequency, which is re-emitted when it returns to neutral - it's incredibly stable and a single frequency which is then counted down to once-a-second.
> The Best Clocks in use are accurate to about a second in 158 million years, the next generation are getting difficult to measure, as they're in the one second in the lifetime-of-the-universe bracket...
> I just distribute the time from 'em, accurate to a ten-millionth of a second everywhere it reaches, the easy bit.
> 
> Dave H. (the other one)



Dave, that is absolutely fascinating! And here I thought that working to .0001'' was accurate (or precise?).
Mike


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## Tozguy

benmychree said:


> I think life was wonderful as a machinist before all this XYZ crap was invented; I'm talking the early 1960s, when we had longnitudinal, cross feed, and little else; on mills, we had table feed, infeed and vertical feed; call me an old fart; guilty!



Know what you mean. But from one old fart to another I've been known to talk XYZ language when I get frisky.


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## Tozguy

astjp2 said:


> Try this on for size, AME
> http://manufacturing.stanford.edu/processes/Turning&LatheBasics.pdf



Very apropos, thanks, but it doesn't say what astjp2 stands for.


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## Tozguy

JohnBDownunder said:


> Oh Dear, Just to confuse things even more perhaps.
> Being one who messed about in boats I referred to the "Y" axis on my mill as the "Port n Starboard" the "X" as "Fore n Aft".  The "Z" was just "Up n Down".  Still do at times.
> It depends on what terms you are used to I guess.  But, when talking to other swarf nuts it is best to learn the conventions and I am still trying.
> John B
> 
> ps. Just had a look at the Turning&LatheBasics.PDF now me ed aches.



John, don't give up mate. When all else fails you can always ask your grandkids to explain it for you.
When we buy a new car, we never take the road until the 'kids' have programmed all those bells and whistles.
I don't talk to cars (yet) but the yunguns sure do.


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## Micke S

It is difficult to remember the axis letter convention. So I cheated with this on my lathe  I may not even follow the rules but it is how I want it.

I use X for the cross feed, Y for apron feed and Z for the compound rest feed. The x-axis is set for diameter change. The DRO is almost a must for me since we normally do metrics and the manual dials on this lathe are inch graduated.


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## John Hasler

Tozguy said:


> My original objective was to identify and adopt conventional terminology when making notes about my machining exercises on a lathe. I keep a log book of the stuff done, what worked, what didn't, and why (when possible). Helps me digest and learn from it. Just thought that referring to the x,y, or z axis would be a new level of sophistication for me
> Thanks everybody for the input.


Just put a sketch in the front of your logbook explaining the conventions used therein and then consistently use them.  Consistency is the only reason for having such standards.


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## Wreck™Wreck

Tozguy said:


> A two and a half axis mill that has 4 axises and a programmable coolant nozzle, boy you really know how to wreck a thread.


Only the best will do, you understand what 2 1/2 axis means I assume?


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## 65Cobra427SC

Great! I think I just forgot everything I learned so far. Only one thing left to do now...


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## British Steel

Tozguy said:


> Dave, that is absolutely fascinating! And here I thought that working to .0001'' was accurate (or precise?).
> Mike



Actually, time's the thing we can measure most accurately, partly because since the 60's / 70's it has been defined by reference to the atomic clocks - Earth's rotation is a bit noisy... So, it was the first "quantum standard" in metrology, as it uses quantum mechanics (the transition in Caesium atoms can ONLY take place at that energy (and so frequency)), so it'll be the same anywhere else in the universe! The other fundamental standards are being redefined with reference to quantum standards, e.g. the Metre is a certain number of wavelengths of a certain light radiation derived in the same way, from a quantum standard transition that the aliens can reproduce as long as they can a) count, and b) find the same element somewhere in their solar system - the Amp is being redefined as a number of electrons passing per second - and some of our eggheads have built pumps that pump individual electrons _and count them in and out _to make the standards - the old definition of the Amp, f'rinstance involved infinitely-long wires precisely a Metre apart carrying an Amp and measuring the force (pretty minuscule) per metre between them...

Sorry, I'll shut up now 

Dave H. (the other one - a bit of a geek)


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## Tozguy

Wreck™Wreck said:


> Only the best will do, you understand what 2 1/2 axis means I assume?



Busted!


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## Tozguy

John Hasler said:


> Just put a sketch in the front of your logbook explaining the conventions used therein and then consistenly use them.  Consistentcy is the only reason for having such standards.



I would but I think Micke needs one more than I do.
Do you have a dictionnary?


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