A8 extruder feed observation port

thingiverse

This mod enables one to offset the stock hot end cooling fan from its standard position, substituting it with a round observation port that allows for direct visual inspection of the extruder's feed mechanism while maintaining airflow through the original heat sink. The purpose of this is to facilitate real-time diagnosis of mechanical issues during operation - such as clogging, backflow, filament grinding, slippage, poor alignment, loose grub screws, and so on. It also makes filament loading slightly more manageable. This mod does not require any destructive modifications to stock Anet parts, making it completely reversible. It is crucial to note that rigorous calculations have not been conducted to ensure proper airflow, and this part has only undergone limited testing on a printer operating at PLA temperatures; therefore, it is strongly advised to closely supervise the machine after installation until satisfied that cooling of the hot end is sufficient even after extended prints, especially when working with ABS or other high-temperature materials. If you use this mod at higher temperatures, please post your results in a comment. One user has kindly informed me that this part currently does not provide adequate cooling for ABS temperatures. This part is best printed upside-down to minimize support material usage and achieve a good quality top surface. The prototype seen in the pictures was printed with PLA using a 0.3mm first layer, 0.6mm wide, and 0.2mm thereafter. During assembly, it is suggested to mount the heatsink alone on the extruder, clamping it to the motor/extruder assembly by tightening down the lowest of three nuts preloaded onto each hex bolt, then slotting the new fan duct between the two remaining nuts and using these to align it correctly before tightening down. The use of washers between the nuts and clamped surfaces, especially plastic surfaces, is highly recommended. Stock M3 screws will satisfactorily tap into the fan mounting holes. The part file is compatible with FreeCAD 0.16.