HGX Lite single-gear drive idler arm

First, look the video Extrusion Quality - Mystery issue resolved ! (youtube.com)

I watched it myself after I was bored and decided to give it a go on my HGX Lite extruder that I have used for about 500-600 hours now. 

Extruder is about 9 grams lighter. Considering it weighs in stock for about 172.5 grams with the motor, then it's safe to say that it's now 163 grams with the motor.

Hardware needed: 1x M5x8-10mm flathead bolt, 688ZZ bearing.

Gains:

• about 9 grams less weight on the extruder/toolhead
• objectively less wood grain/Z-banding on the outside walls
• grip is not weaker in any meaningful amount
• a bit more movement on the idler arm thanks to the dent designed into it right where the extruder bolt is for the toolhead attatchment
• easier to see/remove clogs in the extruder thanks to smaller idler and it can be pulled a bit further from the driven gear
• visual benefit with a material colour of your choosing
• should you want to build another extruder based on HGX Lite gears you now have that option with one extra gear ready to be used
• doing this mod grants you motivation to pull out the three bolts holding the extruder together (base can be attached to toolhead) and pull out other gears aswell, take out the bearings, clean and grease them and put them back in as mine were super-dry after all these hours. This point is just a recommendation.

I printed it with 0.6 steel nozzle out from Rosa3D ASA, layer width of 0.6-0.7, layer height of 0.3, 3 walls and 4 bottom-top layers, minimum layer time limited to 8 seconds with 50% part cooling after 3rd layer with Stealthburner toolhead. Used the very same extruder I printed the part for.

Parts might need to be drilled/filed/sanded depending of how well your machine is tuned. I had to file bottom a bit because the part was a bit wider and did not fit in the extruder that good AND I had to drill the 3mm hole a bit due to it being not perfect for the pin (I recommend using a 3mm nail for it as it removes minimum amount of material and as it heats up it will push the plastic to the sides and makes the wall stronger). 5mm hole for the bearing bolt does not need any rework, just the screw the bolt directly into the plastic but do it slowly.


I have just started to use this mod after I saw it working successfully. I'm waiting on the delivery of new filament order that also has a roll of TPU in it. It's a first time for me to print it but I'll let you know how it goes.