Question: What Direction Is Up?

[edan]

Hello,


I am hoping someone in the manufacturing industry has been presented with this problem before and can help me with the answer.
On a manual lathe above center will be in an upward direction from the spindle center-line and below center will be in a downward direction from the spindle center-line.
So my question is, if you are using an upside down tool on the back of the cross slide, do you reverse the above definition or keep it?
The reason I am asking is that I am trying to sound as professional as I can with a prototype tool holder that I designed and I am not 100% positive with my written explanation of what this holder does.
When I worked we always reversed the above definition in our documentation for a tool on the back side of the cross slide, but as I write the presentation out it just does not sound correct.


Thank you for any suggestions.

 

[aonemarine]

Re define it as something like, below center line as from direction of rotation ? Man that sound weird lol.

 

[tel]

Play it safe - write 'Exactly on centre height'!

 

[tombstone]

If you take the top of the tool ie the bit with top rake as the reference point rather than a line through the centre of the spindle then the cutting edge will be either above or below centreline regardless of tool orientation as another example a tool mounted vertically such as a sliding head lathe would still be above or below centre rather than either left or right of centre
Ray

 

[MuellerNick]

Play it safe - write 'Exactly on centre height'!

How does that look like at a slanted bed lathe?

tombstone got it precisely right!


Nick

 

[TroyO]

I'm a sci-fi reader, and when faced with the similar dilemma for directions on a space ship that is spinning to simulate gravity they refer to it as "Spinward" and "Anti-Spinward"

Not sure that helps, but if I read the terms I would immediately be able to orient the way you meant, LOL.

 

[edan]

Thank you again all of those who took the time to reply to my question.


All of them made me realize that I need to be more descriptive in my writings and also that I need to write to the suggested audience.

 

[lennardhme]

In Oz that would make it the right side up !!!

 

[Lew Hartswick]

Unless you want to use the X Y Z coordinate system, the "above - below" center line sounds easy.

 

[MuellerNick]

Unless you want to use the X Y Z coordinate system,

Below center would be a positive Y, above would be a negative Y. At center would be Y = 0.0
That's true for any arrangement.


Nick