Introduction

After installing the Nevermore and thermistor I started my first print. The first layer went on fine so I left it to continue. I came back later and found the image below.

I ended up disassembling the hotend and found that there was a build up of melted filament. I noticed that my hotend fan wasn’t running even when Mainsail said it was at 100%. Below is an image of the clogged filament.

Printing a Replacement

The Mini-Afterburner was a good toolhead, but assembly was a pain. After some searching around, I determined that I would replace it with the Mini-AfterSherpa. Unfortunately, my Voron was my only ABS compatible printer and it was out of commission. I would need to use my Aquila to print the replacement parts.

Flashing Aquila

I left my Aquila flashed with Klipper, so I needed to convert back to Marlin. I downloaded the latest release of Marlin with the BLTouch-3x3-HS-G32.bin firmware.

I tried formatting and flashing with my Mac, but similar to last time, it didn’t work. My Mac kept putting hidden files that messed up with the flash. I ended up using a Windows 10 machine to repare the SD card.

I formatted the SD card and renamed the firmware to firmware.bin. Then, I placed it into a folder called firmware. After two failed attempts, I tried on an 8GB SD card. I’m not sure what the difference was, but it ended up working.

I had to reverse the extruder motor direction by reversing all of the pins. I then calibrates my steps with this guide. I ended up with a value of 418.2 for e-steps.

Preparing for ABS

I only printed PLA+ on my Aquila, so I wasn’t sure about printing ABS. Luckily, my eSun ABS+ had a minimum temperature of 220 Celsius, so hopefully it shouldn’t melt the shroud. I preheated the bed at 100 Celsius for 30 minutes and then loaded in my filament at 230 Celsius.

Printing ABS

I printed a calibration cube at PIF settings, which turned out fine. Then, I tried to print the Mini-Aftersherpa cowling. The bowden tube ended up popping off the hotend. I think it’s due to heat creep causing a clog. I wasn’t confident in the ability of my Aquila to print ABS, so I’ll paid someone to print the parts.

I comissioned the following parts from the Mini-AfterSherpa, Sherpa Mini Extruder, and FanSaverrepositories:

• MiniAS_Dragon(fly)_Cowling_x1
• housing_core_x1_rev5
• housing_rear_x1_rev5
• [a]_housing_front_x1_rev5
• [a]_idler_arm_long_x1_rev5
• VoronV0.1_FanSaver_rev0.6b

Assembly

My old bearings were stuck in the old toolhead and I needed another shaft for the Sherpa Mini extruder. I ended up buying Bondtech Bearings, a Bondtech Thumbscrew, and a Bondtech Shaft 3x32mm from a local vendor. They didn’t sell any 20mm shafts, so I had to buy a longer one. I sourced new fans from Sparta3D.

First I inserted all the heatset inserts.

Then, I followed the V0.1 manual for assembling the hotend. I also installed the fan saver.

I assembled the Sherpa Mini extruder using the instructions on the repository. The shaft ended up sticking a lot, but it doesn’t bother me.

I mounted both the Mini Aftersherpa and Sherpa Mini to my gantry. I was able to reconnect all but the hotend fan wires to the Umbilical PCB.

Troubleshooting

I checked the voltage of the hotend fan connector and the polarity was reversed. This was fine for the previous fan as it was reversed. After reversing the wires and plugging in the fan, it began spinning. I did a bed screws adjust to relevel the bed and began a PID tune for the hotend.

I noticed while the hotend was heating up that the hotend fan wasn’t spinning. I aborted the PID tune and disconnected the hotend fan. I measured no voltage at all coming from the connector. This led me to believe that the fan didn’t die, but the Neopixel connector wasn’t outputting voltage.

I came back a few days later and noticed that the fan turned on immediately after powering on. After turning on the heater, the fan would stop spinning. I realized that the controller pin was likely reversed and was turning the fan off rather than on. I added a ! in front of PA8 in my printer.cfg. After testing again, the fan was spinning when it was supposed to.

I assembled the hotend and did a PID tune. I tried extruding filament, but the motor kept skipping. There was filament still stuck in the hotend. I used a heat gun to melt the filament and remove the filament. Even after removing all the filament, I couldn’t get any filament to go through the heatbreak. The filament got stuck at the same place as this Reddit post. I ended up buying a replacement heatbreak from Amazon.

After the replacement arrived, I referenced this YouTube video on how to take apart the hotend. I reassembled the toolhead with the heater and thermistor on different sides to match the Umbilical PCB sides. I did a hot tighten of the nozzle, then reattached the silicone boot.

I did another BED_SCREWS_ADJUST to relevel the bed. Then, I did a PID tune with M106 S64, PID_CALIBRATE HEATER=extruder TARGET=245, and SAVE_CONFIG.

I loaded some filament and it extruded fine. I tried pushing filament through the old heatbreak again and found that it went through semi-smoothly. I’ll keep it as a back up heatbreak.

Exclude Object

I added the exclude object module by following ModBot’s tutorial.

I added [exclude_object] to printer.cfg and set enable_object_processing: to True.

Conclusion

This was a very good lesson on why you should have spare parts printed. The new extruder and toolhead being seperate makes it much easier to work with. I’m also going to print all the PIF parts of a V0.2 just in case. The exclude object module already proved useful when one of my parts warped.