Its long been a matter of indisputable fact amongst the 3d printer part makers of the world that it would be impossible to put a viable, functional part moving conveyor device on a moving bed printer. “the motor weighs too much, the wires add mass, the conveyor would shift and fling the part off mid print, etc” . People look at the few “functional” part removers, how big and bulkey they are, and they move on to more productive projects.
I’ve always been convinced that this might be possible though. What if you stripped the motor from the equation and you were just dealing with a pair of lightweight rollers and the belt itself? And then you put the motor on a stick somewhere with a limit switch set to activate when the bed rams into it at full Y maximum extension? And you put a spring actuated brake on it of some sort that prevents the belt from rotating when the motor isn’t in contact? Well, in that case you might just have yourself something viable.
I’m not sure if this one is going to work. There are a few significant hurdles to figure out, but I think I have a decent shot at making it work. For rollers there are a huge assortment of printer part rollers of all sort designed to accept 11" wide paper. I picked up a set of Transfer rollers from an HP laserjet 8150 printer. They are lightweight, fairly strong, used in about 80 different HP printer models so they are cheap and plentiful, and most importantly they have a removable gear with a half moon mounting notch on one end.
The Taz 5 and 6 both have unused M3 mounting bolt holes on the bottom of the bed, and nothing is in the way under the corners, so there is a good place to mount a structure. I figure I can get a tensioner on the back belt easy enough. There is just enough room to pass the belt under the heated bed itself, and a modified aluminum bed plate will allow it to be heated evenly on top, move without snags and allow for installation of guide bars as needed. I have a 24v 300RPM motor on the way that will tap off the PSU, with a standard limit switch in Normally open mode somewhere on it. That will live on a stick sticking out the front of the Taz. That stick will also house part of a chute mount, an identical motorless stick on the other side of the Y axis will hold the other end.
The gear will be a straight tooth gear with a very fine point designed to self allign with the motor gear on impact. There will be an "as yet to be determined matching tooth profile gear brake thingy that will either slide in from the rear or the side when the bed moves away from the motor stick thing, and slide away on impact. I need the motor and position before I can figure any of that out though. Initial test fit of the first roller is promising though. The extra mass doesn’t seem to bother the printer at all so far, and this one doesn’t have the belt tensioner on its y axis yet.
These are likely not final parts, but here they are if you want to see what i am thinking so far. The rear parts will be identical but split with a pivot point below and a screw / heat set insert combo to add tension on both corners. There may or may not be a rear belt brake as well.
I don’t know what the conveyor will look like yet. I have some thoughts on those lines, but I’ll worry about that if I get the other bits working. A buildtak conveyor is a theoretical possibility for example.
Ignore the messed up spot on my bed, thats a 9 month old piece of buildtak and it needs swapped out.
convey2.stl (158 KB)
convey1.stl (80.9 KB)