mmcginnis9272 wrote:MichaelHerron wrote: NEXT--the firmware of the cubepro checks to see if the amount of material that the printed file is going to use is still left in the cartridge. This number is also in the start script. It should be a very small, non-zero number. (.001 works).
The cartridge loaded can be empty!
This may not work forever, but to date, we have not had an issue printing on an empty cartridge.
So, if you don't mind clarifying... the %full on my cartridges will continue to decrease untill they hit 0%, but I'll still be able to print as long as there is filament in the cartridge or externally running into the head? I ask this because currently I'm printing on a cartridge that says it is around 90% full and when I print, the number keeps decreasing.
Yes. Bear in mind that this is what i've noticed--not based on inside knowledge of how the cartridges work:
Before the print, the firmware checks the existing state of the cartridge and compares that with the stated filament length required that is in the bfb file. If the material type between what is loaded in the machine and what the bfb file states is required, AND the length left in the cartridge is within some threshold value of what is quoted in the bfb file, the print is allowed to start. No writing is done to the cartridge at this stage.
While printing, the encoder on the extruder's idler wheel, subtracts from the cartridge just as it always did. If you have a full cartridge loaded, it will continue to subtract from its reported length. It doesn't ever seem to read the cartridge or care that it is empty at this point. It keeps on printing. This is a good thing, you don't want the print to end just because the cartridge may mistakenly report itself being empty. If the filament does run out going to the extruder, the encoder wont rotate and the machine will report a filament error. It does not appear to use the cartridges reported value for this at all. Its as if no READING of the cartridge occurs during printing. (if you remove a cartridge during printing, it WILL let you know! we do know it IS reading, but unless the cartridge is removed, it will keep plugging away)
I've seen reports that there are a fixed number of writes available to the chip AND that the chip needs a higher voltage to write. I've also seen that the chip cannot verify a write without consuming one of its fixed number of writes. None of these appear to coincide with the data sheet for the iButton chip in the cartridge, but i cant be certain.
What i do know is that the printer WILL print on an empty cartridge. If a full cartridge is loaded, it will continue to decrement the length normally regardless of whether that cartridge is actually being used.
Even if we use CubePro materials, we tear open the cartridge and feed the spools in from the top. We keep the same cartridge shells loaded in the machine. Both of our loaded cartridges were reporting full and continued to decrement until empty as we used up the material loaded in from the top. Both have been printing quite a while after being empty.
This party may end at some point, but until it does, we're continuing this way!
