Weak prints

Israel · August 2016

OK, I totally messed up some parameter, somewhere in the application. everything I print is very weak, transparent (at 3 outside perimeter thickness), spongy looking, (you can see and feel it looks very "spongy"), falls apart when twisting the print. I don't know how to recover. would my best bet be to uninstall the application and then reinstall (to get back to the default settings)? I only use slic3r, not cura ( using this slicer will not give me a top layer on the prints). I've never even tried the third slicer, it seemed awkward. Any ideas?

Repetier · August 2016

Reinstalling does not delete settings for slic3r. These are at /Users/<login>/AppData/Roaming/Slic3r as files. delete them to revert everything.

Your problem sounds like too low extrusion. did you calibrate steps per mm to match amount moved in, set filament diameter correct and did not enable volumetric extrusion somehow and set flow multiplier in slicer and host correctly. All these change amount of filament.

Adhesion can also get bad from too much cooling and too low extrusion temperature.

Israel · August 2016

Thanks for the info.

I did calibrate my extrusion steps per mm. I am spot on when I extrude 100mm.

Diameter of the filament is 1.75, Measured filament 3 spot about 1 foot from each measurement to 1.74, 175, 1.76, averaged back to 1.75

enable volumetric is not checked

in slic3r, under filament setting ->filament -> Extrusion Multiplier equal to 1 (default)

In printer settings (by the Emergency stop button) Extruder tab -> Max Volume per second = 12 (default)

What are your thoughts?

Sincerely,

israel

Repetier · August 2016

Sounds all right also for PLA multiplyer is normally 0.85 as it dwells a bit after extruding but that would make things worse I guess.

You could slice a solid cube and compute volume and compare it with what the slicer would extruder (length x cross area). Extrusion will not be 100% maybe 90% of the full volume. If not the slicer settings cause a wrong extrusion. So check that host has selected the profile you set up in slic3r configuration.

Israel · August 2016

Have you seen the problem I described before? It was driving me crazy. My prints would sometimes come out very
loosely formed, with lots of very rough surfaces.

I did everything to figure it out.

I checked the PID, extrusion speed rate, printer and slice extrusion
settings, you name it, I checked it.

It wasn’t until I printed my white ABS that I noticed that when the
object printing started looking good that I noticed the black specks.

I took apart the extruder and noticed that there was a crusty black junk
in the stem that connects to the aluminum block.

Turns out that the Teflon tube
is only rated for about 265c before it breaks down and my printer had a temp runaway printing nylon and shut down at
275.

I do have a question. Is this Teflon tubing used to determine what size
filament the printer can use. It has an inside diameter of 2mm, and the whole
it fits into is 4mm.

If I were to replace it with an inside diameter of >3mm
(or not use any Teflon at all, could I push 3.0 filament thru the printer?

What is the purpose of the Teflon? Does it
act like a washer to prevent the filament from leaking upwards into the
extruder motor?

Is 0.25mm (filament is 1.75mm) difference enough to prevent the
melted filament from leaking upwards?

Just
asking, trying to learn more about this printer.

Sincerely,

Israel

Repetier · September 2016

The teflon tube has several functions. It is a heat brake so filament going up there cools fast and does not move more up. It also is slippery so you can still move down. Drawback is that it limits max. temperature and is not good for high temp. printing. Modern extruders are full metal and they cool the metal near heat break to do the same. The only teflon they might have is at the top from bowden. With this design they can also print nylon. A bit simplicated, but I'm no extruder expert.

Weak prints

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