| I've played with belt systems similar to this. It's great for high-volume small quick-to-print pieces. I would have loved to have used such a system when I was printing first-response medical protective gear early on during the pandemic; I needed high volume and the pieces were small. It sucks for large pieces that require good bed adhesion. A bit of background: A common problem with certain materials, like PETG, is that the nozzle tends to weep. If that's the case, during a large print there may be a buildup of plastic that offsets the nozzle a small amount. At the top layers of the print, where leverage is the highest, if that offset on the nozzle makes contact with the print, it's probably game-over. The nozzle+offset will probably knock the print off of the bed, destroying the part. I experienced two problems with a belt-bed system like this. For one, bed adhesion is generally lower, so events like described above are basically never survived, whereas with a steel insert bed like a Prusa, the part stays bonded to the work surface, but the offset may cause damage to the top of the part, or the offset may contact it and be pushed aside, allowing a healthy print or a negligibly damaged print, rather than a total failure. Secondly : if you print anything complex, requiring thin or small support structures or brims -- it's a good chance the brim or support material is going to stay on the belt for the ride til the next lap. The system I used had a brush that contacted the bed, but it wasn't enough. PETG brims would work their way back up to the printing area, and be printed on top of. In most cases, that's actually ok -- rarely is the bottom of a print important aesthetically -- but if the work surface is offset by the thickness of the brim, then it increases the likeliness that we'll experience the ooze/weep offset described above, given that there is less clearance now for the nozzle to stay away from it. I think belt systems are the way forward, but I think they need to 1) offer better and more consistent bed adherence; the system I used had 2 or 3 slick spots that we avoided because things didn't like to stick, and 2) offer absolute rigidity -- the belt system I got to play with felt like it'd likely stretch over time and enough part removals. |
It seems like another way to solve the problem is to stack hundreds of the steel sheets in a magazine behind an i3 styled machined. When the print is done, the Y axis goes all the way to front of the machine.
It will basically hit the steel sheet in a ramp and unload the sheet, through the front of the machine. (In a clean under actuated robotic style). Move the bed to the other extreme to reload a fresh plate. This would involve a machine with more Y axis range of motion.
If you're familiar with CNC machine tools, this would operate similar to a Brother Speedio Tool changer. Where the Z axis spindle motor actually indexes the tool changer, when Z axis is high enough to engage the tool changer.
Regardless, I'm excited to see how both style machines solve the next stage of lights out automation.