Chinese E3d Replica problem

Hello.

I couldn't resist to try those cheap E3d replica hotends..
In comparison to original Ormerod 0,5 and 0,3 I cannot see much difference in quality (so far). The china model has 0,4mm.

Problem: Even after unscrew the heater block and more thighten against the brass nozzle, plastic squeezes out of the upper thread. Every 15 minutes, the top must be cleaned.
Inside the heater block the brass nozzle seem to be tighten against the thread of the upper thread screw.


First I thought: overextrusion. But lowering the filament amount did not work.

Do you think its possible to add a Teflon/PTFE sealing strip (for threads) without burning it? Any other ideas?

same happened for me. i used some teflon band to seal up the thread. works fine for now.

If it's like the Prusa and the header block and nozzle are different materials (aluminium and brass eg.), then it's important to heat the nozzle up to a little higher than extrusion temperature and carefully tighten the nozzle against the block. This should stop your leaking which occurs because of the different expansion/contraction rates between the metals.

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VortyZA
If it's like the Prusa and the header block and nozzle are different materials (aluminium and brass eg.), then it's important to heat the nozzle up to a little higher than extrusion temperature and carefully tighten the nozzle against the block. This should stop your leaking which occurs because of the different expansion/contraction rates between the metals.

This is a step in installing an E3D hot end, [wiki.e3d-online.com] so I wouldn't be surprised if it would be necessary to do it for a replica version.

Thanks.. The PTFE sealing helps until now.... It leaking comes back I will use the other method.

Keep in mind that the added PTFE will limit your max temp to <327C (melting point of PTFE), however you'd probably have to replace your Thermistor with a thermocouple to go above 300C anyways, and there are very few polymers that need such extreme temperatures.

But I thought I'd mention it.

This thing is annoying. Still have the problem present, but reduced. PTFE band sealing and tightening on higher temperature. My last option (I think) is to add a nut from top against the heaterblock to add an extra sealing force...

Are there any other ideas?

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gazoox
This thing is annoying. Still have the problem present, but reduced. PTFE band sealing and tightening on higher temperature. My last option (I think) is to add a nut from top against the heaterblock to add an extra sealing force...

Are there any other ideas?

The seal is down to the surface finish of the two mating surfaces (between the heatbreak and the nozzle) and the quality of the threading - not much you can do about the threading but you could make sure the mating surfaces are flat and clean by rubbing them down with some 800 grit abrasive paper. Ideally putting the paper on a flat surface and holding them in something that will keep them at 90 degrees to the surface or at least threading a nut on as a guide.

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FatFreddie

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gazoox
This thing is annoying. Still have the problem present, but reduced. PTFE band sealing and tightening on higher temperature. My last option (I think) is to add a nut from top against the heaterblock to add an extra sealing force...

Are there any other ideas?

The seal is down to the surface finish of the two mating surfaces (between the heatbreak and the nozzle) and the quality of the threading - not much you can do about the threading but you could make sure the mating surfaces are flat and clean by rubbing them down with some 800 grit abrasive paper. Ideally putting the paper on a flat surface and holding them in something that will keep them at 90 degrees to the surface or at least threading a nut on as a guide.

Agreed

That is why the original ones cost a lot more QC is much better. Oh and make sure you heat the whole assembly to at least 285 degrees C before you tighten the lot up.

Doug

285°C thats very much. Much more than expected for "heat up little higher than extrusion temperature" . Will try....

My previouse target temperature was 250°C..

Edited 1 time(s). Last edit at 04/29/2015 02:59PM by gazoox.

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gazoox
285°C thats very much. Much more than expected for "heat up little higher than extrusion temperature" . Will try....

My previouse target temperature was 250°C..

See The section on tightening the hot end is at the end of the page.

HTH

Doug