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I got my first printer, a Geeetech Prusa i3, and for the price I paid (160$) I am so blown away. As I saved so much money, I treated myself to a legit copy of Simplify3D, which I am happy with.

I'm using white PLA filament (supposedly 1.75 mm) with a 0.3 mm nozzle. The hotend temperature range is 215-240 °C and the bed is usually at 90 °C (with hairspray it gives a nice shiny solid bottom surface). My goal is to print with 0.3, or with 0.2 if 0.3 is to big for the nozzle (ideally a 0.3 nozzle can print 0.3 layer height).

The problem:

It seems that, especially on the first layer with bigger prints, or any layer that continuously pulls filament through the nozzle (outside lining of a layer), the amount of filament that gets "printed out" isn't enough compared to the amount of filament that is pushed in by the extruder gear. This, in my theory right now, causes the new filament to stay in place until the melted plastic in the nozzle is used, which then makes room again for more filament to be pushed through. Until this happens, the gear slips/clicks and can't pull anymore filament.

The mechanics seem to work well, and I don't think the nozzle is clogged. I would guess that some settings need to be manually adjusted to keep the amount of filament pushed through the nozzle equal or less than the amount the nozzle can actually push through, but what is weird to me is that this happens semi-randomly. I have searched online and the issue intermittently appears with other people, but I haven't found a solution yet.

What settings would I need to test?

Here is a link to some current successful prints and a layer mess up example(batman bust).

My biggest print so far (Batman Bust) is amazing, but even here you can see certain layers where the gear couldn't push filament through and the gear skipped a few clicks, causing it to print less when it was suppose to print on the following instructions. This happens a lot more, but when it happens during an infill you obviously can't see it from the outside. The individual layer-height seems maybe a bit too small (0.1 for batman), and the times where the extruder usually skips and clicks appear when I print bigger sizes (0.2 and 0.3). I want to start printing more complex and bigger things, so using 0.1 seems like an overkill in detail and takes way too long.

Edit:

My filament is the generic Geeetech white PLA that I ordered together with the printer.

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    $\begingroup$ Can you specify the exact temperature your nozzle is at ? You mention 215- 245 °C, 245 °C is way to high for PLA and will result in minor clogs during long prints or complete jams due to over heating and carbonising of the PLA. Just try printing with 215 or 210 degrees only. Also please mention the brand of PLA filament your using . Next your Bed temperature is way to high , 60 °C works fine if your filament is PLA . I also suggest you should mention what are the current values of parameters like print speed, flow rate , number of perimeters , retraction height ?. $\endgroup$
    – Axel Fernandes
    Commented Oct 11, 2018 at 3:57
  • $\begingroup$ @ Pᴀᴜʟsᴛᴇʀ2 Thanks, it's fun and I think it's good Motivation to pursue more engineering and coding projects! @AxelFernandes I don't know these at the top of my head but I will post some of those after work! Could you explain how a hotter temperature would clog it? I would assume that the plastic would melt faster and therefore leave the nozzle easier? $\endgroup$
    – PositriesElectron
    Commented Oct 11, 2018 at 10:14

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A nozzle with a nozzle width of 0.3 mm cannot print a 0.3 mm layer height. You could do that but you should not as you ultimately pay the price in the form of a less aesthetic finish. The general rule of thumb is to maximize the layer height at 75 % of the nozzle width, so a 0.3 mm nozzle would allow for a maximum of 0.225 mm. The rationale is that the filament leaves the nozzle as a tube and needs to be flattened to make it flat and adhere to the previous layer, too high layer heights increase the pressure in the nozzle (more filament is needed) causing a less than ideal extrusion and cause the extruder to skip; this is identified by observing a distinct clicking noise.

Please lower your layer height (try 0.2 mm) and decrease the printing speed to see if this works better.

Furthermore, for PLA, temperatures for the hotend (unless you have some sort of a special PLA filament) and the bed temperature are too high. Please aim to print PLA at about 200 °C with a bed temperature of 50 - 60 °C.

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  • $\begingroup$ This sounds right, I will try this after work. The heatbed at 60 almost always ends up losing the print after the first layer, the hot heatbed (90) seems to work well and helps get the first layer to melt together a bit more before cooling off. I will try this later though and post here again, thanks! $\endgroup$
    – PositriesElectron
    Commented Oct 11, 2018 at 10:10
  • $\begingroup$ Too high temperatures of the bed can cause "elephant feet" and should be avoided. Try cleaning the bed and use a PVA based glue or spray. 3DLAC works very good, but gluestick can also be used. The bed does not need to melt anything, it just is needed to get in the neighbourhood of the glass transition temperature of the filament. For PLA 60 °C should be more than enough. $\endgroup$
    – 0scar ♦
    Commented Oct 11, 2018 at 11:34
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    $\begingroup$ @SeanHoulihane I'm not native English, but I do try my best, sometimes my phone makes up different words than I intend to write, less aesthetic means less beautiful for those who did not make it up from the context. Fixed the typo! $\endgroup$
    – 0scar ♦
    Commented Oct 15, 2018 at 13:06
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I fixed it!

The problem wasn't the temperature, it was the spring that puts the pressure on the little wheel against the gear. That was too strong, so the entry of the extruder was to tight. The gear worked fine and the settings worked well, I just had to adjust the spring a bit to carefully lower the pressure. I just printed another Golden Key and it looks perfect!

Thanks for all your tips on the other settings, I will experiment with tose to see if I can increase quality even more, but it seems to work perfectly now for a 160$ printer :)

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