Change Filament Disables X and Y Steppers Which Cuases Carriage Movement While Changing Filament

[msutas]

Currently change filament routine is as follows:

1. Pause the print
2. Raise Z
3. Move X and Y to filament change coordinate
4. Retract filament
5. Disable Steppers (including X & Y)
6. Wait user input from filament change completion
7. Continue print

The problem is during filament change the user likely moves the carriage by accident. When the carriage moves this ruins the print since relative positioning is not true anymore.

If either X and Y steppers are not disabled during filament change, carriage movement would not be encountered. Another solution would be before continueing print, X and Y axis may be homed in order to get the exact position of the carriage.

[ccie1441]

Did this get looked at? I have the same issue.

[boelle]

its now marked as a verified bug... if some code writer can fix then please fork latest marlin and make the changes and submit a pull request

[boelle]

i just got an idea for this one.... after filament is changed then home x and y... in this way it does not matter if they move... the printer knows where to go to... the problem with move while change the filament is that the moves are not controlled by the printer and it loose sense of where it is... but after a home of x and y it should know where it is

[ZetaPhoenix]

The only I issue I have with this is that in order for this to work
correctly, the end stops must be extremely precise. I would rather fixing
the code to prevent disabling of the stepper driver instead.

-Jon

On Tue, Dec 23, 2014 at 2:07 PM, Bo Herrmannsen notifications@github.com
wrote:

i just got an idea for this one.... after filament is changed then home x
and y... in this way it does not matter if they move... the printer knows
where to go to... the problem with move while change the filament is that
the moves are not controlled by the printer and it loose sense of where it
is... but after a home of x and y it should know where it is

—
Reply to this email directly or view it on GitHub
/~https://github.com/ErikZalm/Marlin/issues/1038#issuecomment-68003974.

[boelle]

that could be an option too.... who is up for fixing?

[msutas]

I found a fix for the problem but I did not upladed it because it was like a workaround and does not change the called procedure. The problematic procedure may have been called in many places and I did not want the go over the whole Marlin code. My change just reenables x,y and z steppers as soon as they are disabled in the change filament code. I will upload the workaround solution since there are others suffering from the same problem.

[boelle]

remember to submit pull request to development branch as noted in the readme on the front page

[bkubicek]

Homing at this point is not an option, as the user might have moved the
head on purpose at the start of the print, especially to move to a good
blue tape location. The right way is only to disable the e stepper in the
routine, which is doable.

remember to submit pull request to development branch as noted in the
readme on the front page

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Reply to this email directly or view it on GitHub
/~https://github.com/ErikZalm/Marlin/issues/1038#issuecomment-68054563.

[Wurstnase]

This is less a bug and more a feature request.
Just disable only the steppers you want!
M84 X Y Z E do that job already.

[boelle]

and if you want to change filament while printing.... because you thought that there was enough filament but there is not and you have to start on a new reel to complete the print....

[boelle]

i partly agree with the others.... it might be that you can go to the lcd menu and change the filament... the printer at this point knows where the nozzle is...

if the steppers are then disabled it will no longer have control over where the nozzle is and unless you are superman you cant change the filament without moving the head....

so either the steppers have to remain enabled during the filament change... or after filament change it will have to home X and Y and go back to where it should be... and yes the idea with homing X and Y can be done precise so you can continue print... the switch does not change precision from when it does home before print...

[Wurstnase]

Anyway. This is not a bug.
To disable the extruder M84 E is what you want.
Complete mechanism to change filament is something else and alot of user need different ways of doing this.

Maybe I'm missing something. Sorry in that matter. Don't use the display often.

[boelle]

you might miss the part that there is an option in the LCD menu to change the filament...

and picture this... you are printing an object and you calculated that there was enough filament... but then you discover that there is not enough...

you then go in the LCD menu and say change filament to load a new reel...

the print stops and moves a bit away to allow you to change the filament...

it then disables the steppers and you change the filament... but upp you moved the head

can you see what happens when you tell the printer you are done with the filament change?

[boelle]

HINT: yes it does automatic disable the steppers during the filament change process....

[boelle]

this one is solved in #1264, closing

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