"Fixing" my 3D Printer's Extruders
2021-02-07 15:22 - Making
I got a 3D printer a few years ago when I came into a lucky collection of free filament. Long story short, things were okay, but I had trouble with the (free) ABS filament, it's extra hard to work with. I got some PLA recently, which slightly but not totally improved things.
I eventually figured out that the cause was a cracked part. The "extruder" of a 3D printer is responsible for pushing the plastic filament down into the "hot end" which melts it, so that it can be laid down into the design in question. This particular part pinches the filament onto the drive gear, so that it can be pushed. And the crack means it wasn't pinching as strongly as it should, so it would slip and not move correctly.
My 3D printer is "dual extruder", so it's capable of using two different filaments at the same time. I almost never use that, so I simply switched over to the other non-broken extruder for a while, but that wasn't a real fix. I ordered some replacement parts, made of metal instead of plastic, and here they are installed. You can see the (brass) gear in the middle, of the metal extruders in red. The spring pushes the top arm up, which pivots on the top left screw, pinching the silverish roller into the brass gear. The plastic filament goes between them, and down from here.
This much is a nice improvement. No longer does the drive gear turn but just slip past the filament, not pushed strongly into it. Now I've got a new problem to solve: for some reason somewhere around the second layer it stops trying to drive the filament at all!
