PROTOTYPE half-tested Captive Nylon/T-Glase Extruders -- for sho

pinshape

These custom extruder designs are heavily modified quick-fit-compatible extruders, based loosely on the initial Greg's-Wade design. In each case, I've enlarged the filament drive path to 6.75mm to accommodate a piece of PTFE tubing, either through the bottom half of the extruder or through the whole body. This is perfect for 3mm filament, as it allows for smooth feeding and prevents over-pressure in the hotend. This modification turns the traditional Greg's-Wade design into a Flexible-Filament compatible extruder. Although tolerances may not be suitable for materials like Ninjaflex, I've found that slightly flexible materials like Nylon blends and T-Glase/PETT can cause issues when not captive. These custom designs solve this problem by keeping the material pressed up against the hobbed bolt in the hotend. Note that even with captive filament, you'll still need a tight idler bearing to keep the material in place in version 8. Version 9 encapsulates the tubing completely and uses an embedded heat-sink M5 Nut to apply additional pressure if needed, similar to the FlexyStruder. This is not necessary in most cases. There will be some overhangs in V8, but this post was primarily created to demonstrate concepts during a conversation on Reprap IRC.