Shenzhen Alu Rapid Prototype Precision Co., Ltd.

Fixing a loose or poorly contacting heat sink on a 3D printer nozzle/heater block is a very common issue (especially on Creality machines, V6-style hotends, or clones). Here’s how to properly secure it again depending on your hotend type.

Common Hotend Types and Fixes

1. Creality “MK8” / CR-10 / Ender-3 Style (Most Common Loose Ones)

The heat sink is usually just pressed onto the heatbreak and held by friction + a small grub screw on the side of the heater block.

Steps to fix:

a.Heat the nozzle to 230–250 °C (makes aluminum block expand slightly and softens any plastic).

b.Turn off heat and unplug the heater cartridge and thermistor (precaution.

c.Use an Allen key to tighten the tiny grub screw on the side of the heater block that presses against the heatbreak flat (usually 1.5 mm or 2 mm Allen).Many people miss this screw or it backs out over time — this is the #1 cause of wobbly heat sinks on Creality machines.

d.While the block is still warm (easier to move), push the heat sink down firmly so there is no gap between heat sink and heater block.

e.Hold it down and re-tighten the grub screw hard (but don’t strip it).

f.Let everything cool. The aluminum block will shrink a little and lock everything tightly.

2. Genuine E3D V6 / Volcano / Most Clones

These use two M3 screws that clamp a groove in the heat sink.

Steps:

a.Heat to 250 °C, then unplug heater & thermistor.

b.Loosen the two M3 screws on the heater block that go into the heatbreak groove.

c.Push the heat sink down firmly until it bottoms out against the block (zero gap).

d.Tighten the two screws evenly (about 0.8–1 Nm, snug but not crazy tight).

e.Let cool.

Pro Tips to Make It Stay Fixed Forever

1.Put a tiny drop of medium-strength threadlocker (blue Loctite 243) on the grub screw(s) after tightening.

2.If the grub screw is stripped or the hole is wallowed out, replace it with a slightly longer screw or use a dog-point/set-screw that bites fresh metal.

3.On Creality machines many people upgrade to an M4 or M5 socket-head screw + nut mod that clamps much harder than the stock tiny grub screw.

4.Make sure the heatbreak flat is actually facing the grub screw (sometimes they rotate).