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Hello I have a Prusa I3 I am currently able to get press fit parts with my current settings. I am using Ramps 1.4 hardware and repetier software and cura as my slicer. I am printing with a .2 mm layer height right now but would like to get a better number such as .1 or .09. When I try to print with say .1mm layer height in the middle of the print the filament stops coming out of the nozzle. However I can still see the gear moving. I have check some sites that I have been using for troubleshooting but I haven't found anything that fixed the problem yet. How or what setting need to be changed in order to print with better resolution?

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There are no settings that you should need to change. Rather, it seems like you are suffering from another issue that is not directly related to layer height.

It is possible that your hotend's heat sink is not being cooled enough, causing heat to migrate up and soften plastic in the heat sink, ultimately jamming it. Depending on your hotend's make, the heat sink should be cooled by a fan that is always on.

Normally, the plastic being fed into the hotend provides some cooling, but printing at a thinner layer height decreases this effect because less plastic is fed into the hotend per time unit.

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  • $\begingroup$ I do have a E3D hot end but I'm still printing the rest of the mounting parts for it , so I wont be able to test it till that's done. I do however have the fan on always and the heat sink has a thermal paste apply for a better transfer. Thank you again Tom I'll let you know what happens. $\endgroup$ – Dakota Miller Aug 5 '16 at 6:51
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I agree with Tom's answer, it seems that temperature slowly makes it's way up your heat sink and softens the plastic which causes the jam.

Even though you should first check your hardware to make sure that hotend cooling is installed correctly, to directly address your original question as to what setting needs to be changed, I would suggest lowering your printing temperature. When printing finer layers, the plastic moves slower in the hotend, spending more time in the heater block, possibly making your current temperature setting too high for this resolution.

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Yes, That is what happens. There is a reason that most people cannot break the .1mm barrier.

You have several things happening. First if you are using a bowden. Good luck. The bowden treats plastic a lot like a spring. Just wont be able to generate a consistent pressure.

The direct gear will have the same issue. You are trying to spit out 0.1mm on a 0.5mm nozzle. Factor in some simple drooling and your dot of plastic is missing. You wouldn't think it matters, but when we are using such tiny amounts of plastic, and consistently throughout the print, it makes for a really bad result!

Then you have more issues. This is why you jam. You now have a lot of plastic sitting, not being expelled. When you go from 0.2mm to 0.1mm you now take twice the time. Considering the printer was made to print at a 0.7 to 0.2 range (more or less). We are talking about a fair time for this plastic to sit molten, waiting to come out. Some have mentioned the heat crawl, but not exactly what happens or a solution. Now you do a retraction, and you just retracted molten plastic. Which gets jammed. Or your plastic cooks, carbonizes faster and clogs your hotend. Sad times! What you can do is ... turn off retraction, and then increase your flow / extrusion multiplier to account for the extra drooling. Part will have a lot of stringing, but a quick burst from a lighter fixes most of that.

You can get better results with a hotend that has a fan and heat sink / break. I like the e3d hot ends. That will stop the heat crawl.

I will note that Makergear once sent me an experimental 0.1mm nozzle. It could not build enough pressure to expel the plastic. I got one tiny bunny, half melted before it clogged from aforementioned carbonization.

Sounds like to me you really just need a form 1, or you are a tinkerer like me. Making the printer go twice the speed is much more fun than high quality.

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  • $\begingroup$ Lol, I am a tinker. I will work and work in till i get it to do what i want. This is very interesting, as i just started 3d printing in april theres still alot i dont know. My work on getting the E3d hotend installed is at a stand still till i get some althread. But what if i changed my nozzel size to .2 and work on the retraction and flow settings? $\endgroup$ – Dakota Miller Aug 8 '16 at 1:18
  • $\begingroup$ Oh yeah it is a fun hobby as you are never able to learn it all. .2 will help a lot. I would also tighten the geared extruder. I'd also start with no retraction, then work up. I also akin 3d printing tinkering to a performer spinning and balancing 3 plates. Got to get everything to work perfectly all at once. $\endgroup$ – StarWind0 Aug 8 '16 at 2:42
  • $\begingroup$ Kk sounds good ill try that and see what happens. I love the analogies. When i first got the printer i had so many mechanical issues it wasnt funny, customer service was poor and i had no clue what i was doing. After couple months of working with it ,most of the sample filament used up. i got it working. Like you said its a balenceing act. $\endgroup$ – Dakota Miller Aug 8 '16 at 8:44

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