This isn’t what I expected from a cold pull. This is Thaulman bridge cold pulled from an e3d v6 at 140C. The tip actually looks fairly clean but that segment just behind it is an air bubble about 1cm long.
That’s normal. When you pull it, you create a vacuum on the filament and you can get artifacts such as this.
never had than that with cold pulling PLA/PHA or nGen
