if/while ?

A DO-WHILE loop does the code then checks the while condition. A WHILE-ENDWHILE loop checks the while condition and if true does the code.

So a DO WHILE loop in sudocode

Do

Stuff
...

Check While condition if true return to top and run again



A WHILE ENDWHILE loop in sudocode

Check While condition if it is True run code if False skip code

Stuff
...

Endwhile

So your do while loop will always execute at least once. Your test condition is while #2 is greater than #1 so it has to be larger before the loop stops. In other words you must pass up your desired target before the loop exits.

You either have to change your relational operator to one that gives you the correct outcome or the loop.

Hidden in the Binary Operators are the Relational Operators.

www.linuxcnc.org/docview/html/gcode_over...sub:Binary-Operators

John

i thought that was the case about it having to be bigger than #1.
but it doesn't go over on the second Do. it goes to .04, so i still don't understand this
do'y think

can i get z to move up(from present depth) .1" and move to another position and start
another cut ? like z at -.4.... move z up .1"(-.3").....move to new position.... z-.5. or
do i need a script or mcode ?


o100 if [#<fin_depth> lt #<depth_of_cut>]
z[.1/1]
o100 else
z#<_safeheight>
o100 endif
g0 x.1 y-.1

Thanks
kenneth

piasdom wrote:

can i get z to move up(from present depth) .1" and move to another position and start
another cut ? like z at -.4.... move z up .1"(-.3").....move to new position.... z-.5.

Yes.

Code:

o100 if [#<fin_depth> lt #<depth_of_cut>] z[.1/1] o100 else z#<_safeheight> o100 endif g0 x.1 y-.1

You probably need to learn to program in a real programming language, and not G-code. But, this is how I do what I think you want to do.

won't this make the end mill go down with each run ? i want the end mill to
come up from current position(-.4 to -.3") - move to new position(x.1 y.1) - go down .1" from
last current position(-.5).

piasdom wrote:

won't this make the end mill go down with each run ? i want the end mill to
come up from current position(-.4 to -.3") - move to new position(x.1 y.1) - go down .1" from
last current position(-.5).

Why do you need an "if" then?

I really don't get what you are trying to achieve, but you probably need to use a variable for Z (like I did with #1), and keep modifying that before you use it.

#1 = 0.4
G1 Z#1
...some moves...
G0 z -0.3
G0 X0.1 Y0.1
#1 = [#1 - 0.1]
G0 Z#1
...

I still don't understand what you are wanting to do, though.