That's a pretty bad idea, the usb virtual serial port used by most 3d printers, because of it's low throughput, can worsen print quality, it's is much better to just upload to the sd via octoprint. For 2d printers I haven't seen any without network connectivity in a decade, and I can't imagine anyone needs 20 2d printers that are so old or cheap they don't network.
Re:Logic board with 20 USB3 ports
by yellowapple on Tuesday September 22, 2020 @10:18PM
(#24562275)
> it's is much better to just upload to the sd via octoprint
That's... pretty much exactly the plan, yes. The printers we're using all (to my knowledge) run some version of Marlin w/ SD support, so we'd be doing this via the M28/M29 GCode commands over that same USB interface.
It ain't clear that OctoPrint supports this directly, but as long as it's able to shove the exact GCode we tell it to shove we should be able to make that happen. Since Marlin's supposed to wait until it gets an M29 command before it starts printing, it seems to me like low throughput would therefore be a non-issue (aside from, you know, the amount of time it'd take to push that data across, but that'd really only be an issue for the first time we're printing a new file).
Indeed, a buddy of mine has at least 6 or so going at once for his 3D printing business, and we're considering a similar sort of strategy (w/ e.g. some box running Slic3r and Octoprint) so he ain't constantly running USB sticks back and forth.