Change extruder on filament runout

Festivejelly

I have an e3d tool changer with a duet wifi board.

I thought occured to me... I have many spools with 40 - 90g of filament on them and I print objects that are around 150g for my small business.

I have an idea that I could load each extruder with roll of filament and have it so that when an extruder runs out of filament, it just swaps to the next one.

I gather id need 4 filament sensors and create some sort of logic that says:

When filament runout is trigger, store tool, get next tool, heat up, prime, resume print.

Is this possible to do with RRF and the duet board or am I expecting a bit much?

OwenD

@festivejelly
Yes it would be possible.
In the latest beta versions you create a file/macro called filament-error.g in your SYS directory.
In earlier versions it's slightly different in name and function.
In your macro you can choose another tool or even cycle through the tools and select the next one that has filament loaded.

Festivejelly

@owend fantastic this is what I was looking for. I guess id need to do some sort of logic to figure out which tool to choose though.

For example swap to Tool X + 1

OwenD

@festivejelly

You could cycle through them with something like this
Note untested and assumes each tool has a filament monitor and is numbered the same way. ie T0 uses sensor 0

Edit:
The original code would select each tool in turn that had filament
A break command is needed to just select the first that has filament

while iterations < #sensors.filamentMonitors
  if (sensors.filamentMonitors[iterations].enabled==true) && (sensors.filamentMonitors[iterations].status=="ok")
    T{iterations}
    break