Inside the extruder heads you will find this.

Have you ever needed to take the extruder heads apart, maybe because of a block? You may have had that irritating ‘bang! bang! bang!’ sounding experience, causing your filament to flow badly. Or even worse a block that results in you not being able to feed the filament through at all. Its snapped in there. So, you hit the point where to hot end is going to have to come off.

Once you finally unscrew the nozzle (not easy, its on there tight) and pull out the offending broken bit of material you encounter this seeming innocuous little thing –


This is an MK9 PTEF insert. Looks unimportant but is key for a few things –

– It smoothly guides the filament to the nozzle so not to catch on anything

–  It helps keep the filament ridged and vertical so it keeps a continuous flow during prints

And most importantly:

– It prevents the material melting until it reaches the correct deapth in the extruder heads

This important component was, in part, missing from my Wanhao, after i replaced both nozzles, which had become carbonised after a number of experiments attempting to utalise PVC as a support structure (it worked but caused some havoc!) So I had purchased two replacement nozzles from e-bay. Upon attempting to install them i have found that the internal diameter of nozzles where too thin to allow me to re-insert the PTEF tubes. So, on the fly i cut them in half so they would sit in place on top on the nozzles instead of being inserted.

This worked fine at first, yet has caused the problem of the filament oozing and leaking out of the various holes and gaps on the extruder block, and result in considerably poorer quality prints and much thready mess around the build.

The lesson – I strongly recommend not getting any internal components from any other sources than the Wanhao site unless you are confident you know what you are ordering. for users in the UK here is the link to the parts page: (i’m sure you can find your equivalent in your country!)

I have a number of bits and bob’s to changed out in my Wanhao so to get it back up to it 100% working order, including new thermocouples, fans and extruder heads, and also recovering the extruder block with new insulating cloth.  See my following blogs pieces for all this.

I hope you can appreciate the time and effort that goes into writing this blog, and of course the cost for my hosting, the materials, and parts for these experiments. So with this in mind, I would like to do a small plug for ‘Toptal’. They are a website who can supply you with a choice of the top 3% collection of professional freelancers for any kind of Software Engineering, Design, and Development you may need, big or small. Please follow this link to see check out the site. If you then wish to hire one of their great people please follow the link or click the banner at the top of the page. Not only do you get your perfect freelancer, but I am also happy to give 50% of my own commission back to you. This may be up to $1000! Everyone wins! –

Also, and particularly if you are reading this in the US, if you want to Wanhao 3D printer, follow this link and on your order enter the discount code “Charlie3” for $5 off any 3D Printer they sell. I also get a dizzying $5 for my efforts! –

Thanks again!