Six methods to unclog the hot-end

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Felix Printers
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Joined: Tue Apr 08, 2014 8:38 am

Six methods to unclog the hot-end

Post by Felix Printers »

The following methods can be used to unclog the hot-end
A clogged hot-end can most of the times be cleaned. There are several methods to do so. The six most common methods are explained below.

Method 1. Overheated extrusion – No disassembly needed
• Heat up the hot-end to 230 ᴼC for PLA or 250 ᴼC for PET and ABS
• Extrude until the filament starts to flow. For extra effect, pushing the filament through the hot-end while extruding is advised.
• Turn down the temperature to normal printing temperatures. While cooling, keep extruding to check if the extruder still has enough pull.

Method 2. Tip-drilling - In case of serious clog in the hot-end tip
• Heat up the hot-end to 195 ᴼC
• Drill out the tip by hand with a 0.35mm drill. Don’t use power tools.

Method 3. Dip and pull - In case of an internal clog in the tip.
• Loosen bolt in front of printer
• Pull out hot-end. Don’t dismantle
• Heat up the hot-end to 195 ᴼC
• Push the filament in by hand until it comes out of the nozzle, then pull it out quickly
• Repeat this until hot-end runs good again.

Method 4. Gravity clean - In case of internal clog on top of hot-end.
This happens when you try to extrude too fast at too high temperatures. What happens here is that the pressure in the extruder becomes so high, that the filament starts to creep up the barrel and base, cools down and ultimately jams. Another cause for this kind of jamming can be a defect in the main cooling fan.

• Heat up the nozzle to 220 ᴼC and let it settle for a while. The top part of the hot-end will become hot enough that the filament will sag due to gravity.
• Now slowly push down the filament to check if you are able to extrude.
• If so keep pushing and set temp to 195 ᴼC, keep extruding slowly until low temp is reached.

Method 5. Inside drill clean - out from inside
• Loosen bolt in front of printer
• Pull out hot-end. Don't dismantle
• Heat hot-end to 150 ᴼCC
• Hold hot-end at the cooling fins and insert the long 2 mm drill through the back. Carefully turn so you scrape off any debris from the inside.
• Don’t use power tools

Method 6. Inside drill - Last resort, filament got really stuck in top part of the hot-end
• Take out hot-end
• Unscrew top part of hot-end
• Put it in hot-water and push out/drill out the filament using power tools
• Make sure to clean the hot-end of any drilling residue like metal fragments. Use compressed air for ultimate effect.

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Joined: Mon Jun 09, 2014 1:54 am

Post by kerog »

Great information!

Here's some stuff I've been doing; would be curious to see if any of it is bad.

Sometimes I get filament stuck in the cold end. First I disassemble the hot end, then I try pushing the clogged filament either direction with some thick copper wire. If that doesn't work, I get out a small butane torch and heat until the filament bubbles out and burns. Not sure if remaining residues would be bad for the printer, but it seems to work for me.

If the filament is clogged in the peek, I disassemble the peek from barrel and hot end, then push on the bit of filament with an allen wrench. It will generally pop out with a bit of force.

If the barrel or nozzle are clogged and guitar wire won't clear it, I bring out the butane torch again.

Remember, when using the torch make sure you've disassembled from the PEEK first; you don't want to melt it.

Again, these techniques have worked for me, but I don't know if the Felix guys would recommend...

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Joined: Thu Mar 02, 2017 5:42 pm

Post by Smh69 »

Such Great Information.

I love the 2, 5 and 6 Method.

Thank you for this great post. I hope it will help everyone.

Tom Hardy
Posts: 4
Joined: Thu Jul 19, 2018 10:36 am

Post by Tom Hardy »

Nice information and I would just like to add that while you follow any such methods, it is important to keep track of the safety precautions. Wear safety gloves while doing so and also wear googles and mask etc. to prevent any mishap during the extrusion.

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