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IndustryArena Forum > Machine Controllers Software and Solutions > G-Code Programing > Can I do a absoute linear move on one axis, and a relative a-axis move same time?

# Thread: Can I do a absoute linear move on one axis, and a relative a-axis move same time?

1. ## Can I do a absoute linear move on one axis, and a relative a-axis move same time?

Just checking - I make a part with rotary indexing and it would go faster to do an absolute y axis move at the same time (asyncronously) as the A axis is doing its thing in relative mode... I don't want to sync axis, just rapid them both at their own max speeds at the same time... is that possible?

2. G00 for both on the same line?
Al.

3. No idea about A-axis, but G00 X_ W_ and and G00 U_ Z_ are permitted on a lathe.

4. If you do G00 Y... A... they are both absolute.
If there is a letter for relative A axis then you can use it if it's a lathe.
On a lathe with C axis, relative is H.
But there is no A axis on a lathe so there is no relative A axis letter.

If you switch your A Axis to make it C then H may work if it's a lathe.
If it's a mill it probably won't work because on a mill you can only switch
absolute/incremental mode using G90/G91 and the CNC-controlled axes are
restricted to X Y Z A B C (and in special cases additional axes U V W)
A mill does not understand any axis movement as relative unless you specify
G91 first and in that case you specify only X Y Z A B C

So the short answer is 'no'

5. Originally Posted by Spinnetti
Just checking - I make a part with rotary indexing and it would go faster to do an absolute y axis move at the same time (asyncronously) as the A axis is doing its thing in relative mode... I don't want to sync axis, just rapid them both at their own max speeds at the same time... is that possible?
Post your code as it is now. I was to see what you are currently doing.

6. ## G00 > rapid, individual or combined move ?

for fanuc 21iA/31iB see parameter 1401#1, LRP, where this decision is made.

only if your lathe is set for G-code group A would X(in abs) W(incrimental) combination work in the same line.

G-code group B & C works the same as a milling control where only one ,G90 or G91, is valid for the whole line.

if you need prm.1401#1 setting to be different in some parts of your program ,to your own preference, G10 can be used when needed.

7. He doesn't say, but it appears he has a mill so W does not apply and he has
to use G90/G91 and then all movement on one line is either one or the other.
Just program it all in absolute and move on.

8. Thanks for the replies.. Answer is no, it doesn't work... not on my machine anyway.

I wanted to do true coordinated moves but can't because by default the tormach rotary table doesn't know where it is. I can work around, but was just trying to reduce cycle times by doing my a and x/y/z moves all at once.

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