Axis Directions

[ptjw7uk]

I am getting a little confused as to the correct directions the table on my mill should move. If I figure correct on the x axis when inputing x+ the table should go to the left ie the work goes x+ and the same for the Y axis and the z axis will raise the head(more clearance to the work).
I am assuming that for a gantry mill or router x and y are reversed in the the work is stationary and the table moves. The z axis shoul be the same in both cases.

Or have I got it all wrong.

Peter

[John S]

Peter,
See here.

http://books.google.co.uk/books?id=JNnQ8r5merMC&dq=google+smid+cnc&printsec=frontcover&source=in&hl=en&ei=eKyjSpfKD9W6jAes9cW_Dg&sa=X&oi=book_result&ct=result&resnum=11#v=onepage&q=&f=false

Page 7

if you can get this book, do so, it's the best book ever written on the subject and is rapidly becoming the bible.

.

[Kn8]

Hi Peter,

Have a look at

http://www.cncci.com/pdf/notes%20page%20example.pdf

John, very interesting book.

Ivan.

[John S]

There is something called a right hand rule where you stick two fingers and a thumb in the air and each way points plus.

http://www.utm.edu/departments/engin/lemaster/Auto%20Prod%20Sys/Lecture%2025.pdf

Page 3

Only problem is I can't get my fingers to point this way.:sad:

[Lee Roberts]

Good question peter and one i have asked before, Nice one for the links guys, i'v just made this a sticky.

[ptjw7uk]

Hi just found this on fleabay for a Boxford mill

Shows the directions table and head should move in(I think)

Peter

[John S]

Only problem is Denfords started off wrong, they decided that their way was best and because this was based in education Boxfords had to follow or be odd man out and it's a case of it's stuck.

Industry uses X and Y opposite to this and all industrial text books CAM programs etc all work this was.

[ptjw7uk]

Not sure I understand why industry is going to be different.
If I want to machine a part from an industry standard drawing in which the origin is bottom left at 0,0 then I want to machine 0,0 to 1,0 then on my mill the table will move to the left as the head cannot move as on a gantry, so to my mind denford is correct.

Peter

[John S]

Never equate bed movement with direction.
It's always tool movement.

This way all axis move the same.
Denford's way means the bed moves in X and Y but the head [ tool ] moves in Z

[A_Camera]

The reference is the cutting action, not table movement. You can have a table which moves in both X and Y directions, or only Y or only X, or a moving gantry, where the table is stationary, but the cutting directions should always be the same.

30870

Here is a picture for a moving table version, but really it doesn't matter if you think about cutting directions.