Automatic spool switching, config help request

General Discussion
1

Hello!

I almost finished building a large (1275x300) printer, and I want to use Klipper for it.

I want to make automatic spool change system, so printer would not stay idle if spool ends during the night.

My idea:

  • Single nozzle, single direct NEMA14 feeder on the printhead
  • Y-adapter for filament
  • 2 x simple NEMA17 feeders on the back of the printer, connected to Y-adapter
  • 2 x BTT SFS v2.0 filament sensors.

The BTT SFS v2.0 filament sensor has two switches, one for filament presence, second for filament motion.

So, before starting the print I install two spools and instert filament up to the Y-adatper.
Print starts from first spool. Direct feeder and first feeder on the back of the printer are pushing filament synchroniously.
When spool ends (detected by fillament presence sensor):

  • Pause and park printhead
  • Retract first spool filament up to the Y-adapter entrance
  • Check if filament is present in the second feeder
  • If yes, disable first back feeder, enable second. Disable first filament sensor, enable second.
  • Feed filament up to nozzle.
  • Purge, continue printing.

Same for switching from second to first spool.

Is it possible to implement with Klipper? If yes, where to look for solution? I could not find anything about such setup.

2

Generally, yes. Like it is done with the MMU2 adaptation of Klipper for example.

You did not mention what type of printer it is: Cartesian, CoreXY, Delta, …

3

It’s H-BOT.

I totally forgot about MMU. Great place to start digging and great opportunity to learn Klipper scripting. Thanks!

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