Defining custom build volume

General Discussion
1

Hi everyone,

I am the owner of a Delta 3D-printer running Klipper (FLSUN V400). I would like to make a purge bucket for multi color 3D printing. Ideally, this would be located outside of the build volume of the printer. My printhead is physically able to move outside of the print_radius (defined in the config file), but only if the printhead remains between the ‘towers’.
So my question is as follows:
the documentation only shows the definition of ‘delta_radius’, and ‘print_radius’ in the printer config file. Is it possible to define a build area that is not circular, but a custom shape? This would allow me to make a purge bucket between the towers of the printer, without risking a collision of the printhead with one of the towers. I could not find any information online or in the documentation about this subject.

Many thanks in advance!

2

Hello @teddy !

I try to explain:

The firmware defines the print area: This is the complete are that the printhead can reach. Inclusive purge devices.

The slicer defines the build area. The area where the model is build excludes the purge devices. But the slicer can provide moves to the purge device that is outside the build area.

If you want to use the purge bucked as such, the firmware must provide the move ability of the head to the bucked and therefore it can’t be excluded from the print area.

So it’s all up to the slicer.

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To echo @EddyMI3D, unfortunately, you’re just going to have to use a print_radius that allows you to reach the purge bucket at the risk of hitting towers, then make sure your slicer has the print volume calibrated correctly so that it never commands the printhead to a position that would hit a tower. That way you’ll never have to worry about hitting a tower during regular printing, and then you just need to be careful when manually commanding the printhead from your frontend of choice.

Once thing you could do for extra protection in this case would be to create a macro for manual moves that wraps the G1 command but contains a conditional check of the coordinates and throws a warning instead of moving the printhead if you accidentally command it to a position that would hit a tower.

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Hello @EddyMI3D,

Thanks for your response!
Just to make sure I understood you correctly, are you suggesting the following?

  • Increase the print area in the printer config file, but not in the slicer (except for the purge area)
  • Does this mean that, in theory, a ‘wrongly’ configured slicer would make my printhead collide with the towers of my Delta printer?

Many thanks in advance!

EDIT
@theophile just answered those questions. Thanks a lot for the information!

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