Ext Printer "Blobby Boi": How to Fix External Surface Blobs
If your 3D print looks like it has a bad case of acne, you’ve met the “Blobby Boi.”
Nothing ruins a perfect print faster than small, rigid bumps scattered across the outer surface. In professional terms, this is called blobbing or zits. In community slang, it’s the dreaded "Blobby Boi."
Here’s why your external printer (ext printer) is producing these blobs and how to fix them.
Step 1: Dry Your Filament (Seriously)
Place your filament in a dryer at 50°C (PLA) or 65°C (PETG) for 6+ hours. If you hear popping or see steam, you have found the culprit.
Primary Causes:
- Power Loss Recovery (Most Common): The printer saves its progress every few seconds. On complex curves, this tiny pause creates a zit.
- Retraction Issues: The printer fails to pull filament back before moving to the next layer, leaving a dribble.
- Wet Filament: Moisture in PLA or PETG turns to steam, expanding and popping out blobs.
- Over-extrusion: Simply pushing too much plastic per millimeter.
The "Ext Printer Blobby Boi": Causes, Cures, and Cultural Phenomenon
If you have spent more than five minutes in a 3D printing Discord server or scrolled through the dark depths of r/FixMyPrint, you have likely encountered the phrase: "ext printer blobby boi."
At first glance, it sounds like a rejected Pokémon or a niche indie game character. In reality, it is one of the most frustrating, hilarious, and pervasive problems in FDM (Fused Deposition Modeling) printing. The "ext printer blobby boi" (short for extrusion printer blobby boy) refers to a print that suffers from severe over-extrusion, zits, blobs, and layer inconsistencies—resulting in a model that looks less like a smooth miniature and more like a plastic Frankenstein covered in acne.
This article will dissect the anatomy of the Blobby Boi, explain why your extruder is creating these unsightly bumps, provide a step-by-step repair guide, and explore how this technical flaw became an accidental mascot for the 3D printing community.
Step 5: Reduce Outer Wall Speed
Slow down to 20–30mm/s for external perimeters. High speed prevents pressure from stabilizing, creating inconsistent extrusion blobs.
Option 2: The "Tech Support/Meme" Style (Best for Discord or Forums)
Subject: Has anyone seen this guy? 🧐
Body: Name: Ext Printer Blobby Boi Location: Currently encasing my heatbreak in a mixture of PLA and regret. Occupation: Professional Heat Creep Enthusiast.
If you see this absolute unit forming around your nozzle, do not engage. Do not try to print through it. Send help (and a heat gun).
On a scale of 1 to "buying a new hotend," how bad is your Blobby Boi today?
What Causes a "Blobby Boi"?
A "blobby boi" occurs when too much plastic accumulates at a single point where the printer starts or stops a layer. The extruder pauses briefly, but pressure inside the nozzle still forces filament out.
