Moving nozzle up down

fcwilt

Are those commands with Z25 and Z-25 supposed to be relative moves? The values suggest they are.

If you are in relative mode then the G1 X0 Y0 is working as expected.

Frederick

Arnix_2

Are those commands with Z25 and Z-25 supposed to be relative moves? The values suggest they are.
*** I understand that this last command is not executed because i entered 91, which triggers relative movement so X and Y is will be processed on the same way but i dont know how to make this otherwise.

So, what would you suggest to make simple pickup routine like:

locate object on some position --> X100 Y30
move down/up
move to some predefined position --> X250 Y10
repeat

When i was using stepper motors this pickup part was working OK..

A.

fcwilt

Hi,

Well just proceed any relative move by a G91 and any absolute move by a G90.

You can switch back and forth from relative to absolute anytime you need to.

Frederick

Arnix_2

OK. This is working as i need to..
I will test this with external program but as far as i can remeber i did not put extra G90 commands into code...
Anyhow, thank you !

Btw. If you have time/wish please look at my other post regarding nozzle positioning:
https://forum.duet3d.com/topic/12566/nozzle-positoning-problems

Working solution for test up / down movement:

G28
G1 X100 Y60 F15000
;---------------------------
G91
G1 Z-25 F6000
;--------------------------
G4 P150
M106 S255
G4 P150
M106 S0
;-------------------------
G91
G1 Z25 F6000
;--------------------------
G90
G1 X0 Y0 F15000

Veti

This post is deleted!

dc42

@Arnix_2 said in Moving nozzle up down:

This does not work :
G28
G1 X100 Y30 F15000
;---------------------------
G1 Z-15 P60 F6000
G4 P150
G1 Z15 P60 F6000
;--------------------------
G1 X0 Y0 F15000

Bear in mind that your ~~M108~~ M208 Z limits also affect whether Z moves will be accepted.

fcwilt

@Arnix_2

There is nothing wrong with extra G90/G91 commands but remember that once you change mode (absolute/relative) it stays in that mode until something else changes it.

So in this case that second G91 is not strictly needed but it doesn't hurt.

Now backing up to the G28. Since this is going to invoke your homeall file you may not be sure what mode (absolute/relative) is active when G28 completes. So it would be safest to add a G90 command before the G1 command.

Glad to hear you got it working.

Frederick

dc42

@fcwilt said in Moving nozzle up down:

Now backing up to the G28. Since this is going to invoke your homeall file you may not be sure what mode (absolute/relative) is active when G28 completes. So it would be safest to add a G90 command before the G1 command.

Not necessary, because whenever a macro file executes (including a homing file), the G90/G91 state is pushed and popped around the call to the macro file.

fcwilt

@dc42 said in Moving nozzle up down:

Not necessary, because whenever a macro file executes (including a homing file), the G90/G91 state is pushed and popped around the call to the macro file.

I had forgotten that. Thanks.

Even with that fact we don't know what state exists before the G28.

Frederick

fcwilt

@dc42 said in Moving nozzle up down:

Bear in mind that your M108 Z limits also affect whether Z moves will be accepted.

Do you mean M208?

Frederick

dc42

@fcwilt said in Moving nozzle up down:

@dc42 said in Moving nozzle up down:

Bear in mind that your M108 Z limits also affect whether Z moves will be accepted.

Do you mean M208?

Frederick

Yes!