Exorcizing the E3Dv5 PLA jams. Also: Lithophanes

After my previous experiences with the Sumpod, the Rostrap and their hot ends, I would never have put the E3Dv5 on the TronXY X5S in bowden configuration. E3D themselves limit retraction to 2mm for their full metal hot ends and my X5S needed 6 to 7mm to keep the nozzle from dripping. I thought in “direct” configuration (with the Prusa extruder) I would be safe from it doing the Bob Marley and jammin’ all the time, but it didn’t work that way…

Murphy’s Law struck, while our 10th wedding anniversary approached. Absolutely the wrong time to have your prints failing at random. As I had worked with a goldsmith for our 5th, I wanted to prepare at least one of those Lithophanes – and they print at least half a day.

My first attempt to fix the issues with PLA were to add some heat sink grease to the thread on the heat break. OK, it’s only what I scraped off an old CPU cooler, but still better than nothing. E3D startet with this at some point – after I got my v5 from them.

As improved heat transfer didn’t do anything and I did not want to resort to “seasoning” the hot end with oilers again, I startet to dive into the topic once more. Everything this blog post describes as an improvement can also be seen as a flaw of the old design. And surface quality of the HeatBreak is among those (possible) flaws.

In the “Tronxy & Turnigy X5S, X5SA ,X3S 3D Printer Drucker Users” group on Facebook I also read about how the others polished their (mostly chinese) heat breaks and received the hint, that tungsten disulfide might additionally improve the non-stickyness.

But I got myself a 2mm reamer and some penetrating oil with Teflon additive first.

Also used the reamer on the heat sink (the v5 doesn’t let the Bowden tube pass). And then I tried to remove the debris with what I had – paper towels, double-action pump, toothpicks.

As I had made my experiences with wood filament blocking a 0.4mm nozzle, I searched my parts afterwards and found a 1.0mm one – perfect for flushing out everything. It’s chinese made, but brass can be polished easily (at least compared to stainless steel). So this surface is also crossed from the list.

It’s fascitaning to watch the machine squeeze out that much plastic, but the 5015 blower couldn’t cool it down anymore at some point. The PLA curled up until I got layer shifts from the hot end constantly crashing into the curled-up stuff. So you don’t really get a higher print speed anymore. Here is a video for you to watch the extruder turn really quick anyway:

The part I printed here is a reinforchement for the flimsy “MasterSpool Remix by 87squirrels“, that can be bent by the filament being pulled off the spool while printing. I didn’t want to throw it away, so I designed this glue-on stiffening.

IMAG0399

Afterwards I switched back to a 0.6mm nozzle and discovered: My PLA jams were gone completely!
The surface finish of the heat break and/or the old 0.4mm nozzle seem to be what caused the problem. (Or at least part of it. Printing very fast with a very small nozzle will inevitably compress your filament more than with a bigger one.)

So I don’t have to go shopping for tungsten disulfide. πŸ™‚

What about that Lithophane?

As they are not simple band logos (vector graphics), OpenSCAD will not generate them via command. You can use an online generator like http://3dp.rocks/lithophane/, but the output couldn’t be used directly and is too complex for TinkerCAD. And OpenSCAD will not import it, because there is always something hidden in the mesh it doesn’t like.

After searching for a while, this model on Thingiverse pointed me not only to this (more flexible) online generator, but also (via it’s Facebook page) to a generator that runs on your PC. Great piece of software – put out exactly the lamp shade I wanted!

As I printed the adaptors for our (existing) lamp seperately, I had to scale the actual Lithophane up a bit. So the “white” walls are not +0.4mm, but about +0.48 and the “black” walls about +0.96mm additional to the minimum. Lamp parts are here and here on Tinkercad.

Was it finished on our anniversary? Yes. Because I printed it in PET, before all the hot end surgery even started. πŸ˜‰

 

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