My printer can now AUTOMATICALLY UNLOAD itself and start a new print, ad infinitum - this means I can leave my printer unattended printing a series of objects, it prints an object, clears it off the bed, and then prints the next object. As many times as you want! My own little automated factory!
This should also mean that jobs can be sent remotely to the printer over octoprint or similar, the printer can start unattended finish the print, eject it, and wait for the next job.
I am printing a TON of gears so I can teach 11-12 year olds about gear ratios (I’m an engineering teacher as well as a hotend vendor!) and having to unload and restart prints was taking up too much time. I am going to need around 200 gears in total.
So I made a really simple “ram” for my X-Carriage - just a piece of bent aluminium sheet, but could easily be a printed part. This goes on the front of the carriage hanging down so it almost touches the bed (1mm of clearance) when Z is homed.
Using a glass bed (with some cheap hairspray which helps things stick a lot) and printing in PLA the parts detach very easily from the bed once it is cool.
Print a few objects in the front half of your bed - Don’t use a skirt - (see later info about nozzle priming.)
Bring bed to front (hotend and ram now at back of bed behind objects)
Home Z (Ram lowered behind objects, nozzle against bed prevents oozing)
Turn off bed temp and Dwell for 6 minutes (time taken for my bed to cool enough that the parts come loose)
Push bed to back of printer, so the ram pushes the parts off the front of the bed.
Repeat forever.
(The above actions are obviously executed automatically with GCODE commands)
I have a little stiff card chute taped to the front edge of my bed that stops parts falling into the smooth rods/belts etc and instead guides them to a bin for collection.
You can eliminate problems with nozzle priming by quickly moving the hotend away from a print and homing Z, so the bed blocks the nozzle from oozing and it remains primed for the next print. A big retract might help here too, but I haven’t bothered E3D hotends really don’t ooze much at all. You just need to prime the nozzle right for the first print.
I’ll get photos, video, and GCODE tomorrow.