Struggling to fine-tune print quality  

Re: Struggling to fine-tune print quality

Is this being printed from the gcode files from Prusa, or did you slice this one yourself? Did you by any chance change nozzle sizes? It really looks like your extrusion widths are messed up, more that I'd expect from simply adjusting extrusion multiplier in your slicer. If the 2nd was printed from the Prusa gcode, look for hardware factors. If it wasn't printed from the Prusa gcode samples, try that one and compare.

Re: Struggling to fine-tune print quality

Thanks for the reply. Both were posted using the Prusa gcode. I’ll continue to work with the hardware factors. It looked to me like an underextrusion issue. I spent some time yesterday with a simple object I created and sliced in the Prusa version of Slic3r and played with the extrusion multiplier and other factors. Seven prints were virtually indistinguishable and all looked similar to the second badge. I was using multipliers up to 1.2 and expected some difference, but saw little. As I adjusted Z lower, I was hoping to see more smoothness, but it appeared to rough up the surface more. Is it possible to get a partial blockage in the nozzle that could limit flow? Beyond using an accupuncture needle and changing filament, are there other ways to test for it or clear it?

Pete

Re: Struggling to fine-tune print quality

Raise the extruder up so you can get a good look at it, warm it up and extrude some material. (Settings->Move axis->Extruder on the front panel). Does the filament come straight out, or "drag" to one side? If a bit of filament has accumulated, clean it off and observe. Extruding at an angle can indicate partial blockage.

Do you hear extruder clicks that you didn't hear before? That might also be another indicator.

It really looks like you're simply using a thinner nozzle. It looks very consistent, just way too thin. Using the Prusa gcode eliminates any slicer concerns. I'm not aware of any firmware settings that would cause this.

Have you done any cold pulls? If not, it might be a good time to learn the technique. I've had good results using the eSun cleaning filament between nozzle changes.

A spare nozzle is a good thing to have, if only to eliminate that as a possible issue. FYI: You can get a cheap nozzle kit on Amazon that has craptastic nozzles (although they seem fine for PLA) but also a handy wrench and socket set that you're a lot less likely to drop a hot nozzle onto your lap with. If swapping nozzles, read the instructions. Only use 2 fingers to tighten, not too hard!

This might be a good one to contact support with. Be sure to send them both pics, and let them know you're printing the Prusa gcode. Good luck with it!

Re: Struggling to fine-tune print quality

Thanks again. You’ve given me some good stuff to try. I’ll give your suggestions a try and post back my results.

Re: Struggling to fine-tune print quality

You might want to track this thread. Looks like a similar issue. Someone there mentioned Z-level. Is the filament sticking well to the bed on layer 1?

Edit: Also, as it prints, open up the menu with the front knob and check Tune->Flow and verify it's at 1. Do this mid-print or the Tune menu won't show up. For all the limitations of Simplify 3D, they do have an excellent troubleshooting guide. Unfortunately, other than extrusion rate, I don't see anything that could be caused by the pre-generated gcode.

Re: Struggling to fine-tune print quality

This is frustrating problem. It seems possible it is a clog. I get some curling of the filament when I start printing. I don't know whether it is normal behavior or not, but when I load a new filament, it takes 3-4 prompts before any filament extrudes. I have a replacement nozzle and some materials on the way to allow me to do a hot or cold pull, so I'll see what comes of that. I'm pretty sure my Z is tuned pretty well - the first layer looks great and when I lower it or raise it, quality seems to worsen. Changing the flow and the print speed doesn't have a noticeable impact (It was set to 100% to start). In the coming days, I am going to try some higher extruder temps and do a hot or cold pull to see if I get some better results.

Re: Struggling to fine-tune print quality

Update:
I spent far more time on this during the past two days than I thought I would. And to my dismay, I have seen very little difference in quality.

Since my last post and through yesterday, I:

* used cleaning filament to perform an hot pull and cold pull.
* replaced the extruder head altogether
* conducted a factory reset and completely recalibrated the device using the wizard
* tightened x and y belts slightly
* Disassembled the extruder mechanism, re-built it and re-calibrated.
* confirmed the extruder filament gears are aligned with the filament
* switched filament back and forth between the gray filament that came with the printer and some black Hatchbox filament
* tried a variety of z-level settings to see if I can get different results
* manually confirmed I get 100mm of filament pulled when I manually advance the extruder motor by 100mm (it was within 1mm)
* used the tune menu to independently slow the print speed and increase flow
* flashed the printer with the July 2 3.3.0 firmware

Today, after some more searching of the forums and the web in general, I
*lowered the PINDA probe slightly and recalibrated Z
*flashed the firmware back to the 3.2.0 version that shipped on the device and re-tested
*flashed it back to the latest version (3.3.0) when I saw no difference in my test prints
*printed a number of the small test prints I have been using as a proxy for the full Prusa badge (for Prusa gcode) and used the tune menu to change flow and speed to see if there are any results. My test print is a small 1cm x 5cm x 6-layer block sliced using the latest Prusa version of Slic3r. I have been using the Tune menu rather than the detailed parameters in the Slic3r so I can reproduce the behavior I see in the stock Prusa badge code without re-slicing.

My tests (pictures at the end of the post):
* 1: Default settings, 1.000 Z
* 2: 105% Flow, 1.030 Z
* 3: 109% Flow, 1.030 Z, Speed 80%
* 4: 115% Flow, 1.030 Z, Speed 80%
* 5: 120% Flow, 1.030 Z, Speed 80%
* 6: 130% Flow, 1.030 Z, Speed 80%

What’s working well:
* first layer looks great and sticks to the base very well.
* the second layer also looks pretty good
* increasing the flow and decreasing speed has definitely improved the quality of the print - I no longer see gaps in the middle of a line of infill like I did before.
* Aside from this one extrusion issue, the print appears accurate

What’s not working well,:
There are still a lot of quality issues in my current badge print that weren’t there in my initial badge print. Such as:
* my perimeters layers don’t bond well to each other
* there are still gaps between the perimeters and the infill at all levels except for the first two
* the top layer isn’t “smooth”. It is rough visually and to the touch on the top side (though the bottom is nice and smooth)

Are my expectations too high? It still looks like it is under-extruding, even though the flow was cranked up to 130% in the most recent prints.

Plans for tomorrow and lowering the Z further again and printing something less flat to see what it might tell me.

Re: Struggling to fine-tune print quality

I do not think I saw Extruder Calibration in your list of things you tried. For each filament, it is important to run the extrusion multiplier calibration to confirm that the correct amount of plastic is being extruded.

Re: Struggling to fine-tune print quality

What is your Z level setting. I had to go up to 0.750 on the first layer calibration. My prints are working well. Also try to unclog your nozzle with a 250 filament load. I pull the filament, preheat for the 250 setting, load the ailment, and immediately go to tune and reset the temp to 215. Overall it looks like you are getting under fill, do a google search on that, and you will find lots of info.

hope you get it, this seems to be a great printer, but check you first layer and get a good bead there. I found that make a huge difference.

Re: Struggling to fine-tune print quality

It should not be this hard - I think there is something very wrong and would not call this fine-tuning.

An easy test you can do is to check the extrusion distance with a tape measure or ruler.

0. Load some filament on which a marker line will show (not black)
1. raise the Z way up
2. [Preheat] [select your filament, hopefully PLA : ) ]
3. measure 100mm up from the top of the extruder at the point the filament goes in and draw a line on the filament with a permanent marker.
4. wait for the nozzle temperature to reach the set point (maybe 215C ?)
5.[Settings][Move axis][Extruder]
6. Look at the number there and add 100
7. turn the knob until you reach that number. You will have to go in steps - it will not let a person do this all at once but eventually you should be able to add 100mm.
8. Watch the marker line on the filament, it should come down to the point you measured from.

I just did this test on my machine and it was within 2mm or better over 100.

I have not ever changed my extrusion settings and typically keep most settings at the default - with the exception of slowing PETG to make it stick more reliably on the first layer.

Re: Struggling to fine-tune print quality

Wow. I went through the Extruder calibration using Pronterface and the link that gaston.d3 suggested. I had done this manually using the Move Axis menu earlier but dismissed the results as a misunderstanding on my part.

When I ran through the diagnostic portion of the process, I found that rather than extruding 100mm of material - I only got 50mm! Exactly 50mm, actually. No wonder I was seeing under-extrusion. I was only spitting out half of the filament expected! I went through the calculations but haven't issued the M92 command to change the default behavior of the printer yet. Instead, I reprinted the badge and tuned flow to 200% and viola. I got the much better results I had at the start (see picture). Now I'm in the ballpark and can work on finer grade tuning rather than just trying to get basic results!

Any ideas on what could have caused this problem? Is there a way to reset all of the printer values to factory original values to start "clean"? It seems that a factory reset doesn't actually wipe configuration or other data like this.

Thank you everyone for your help!

Re: Struggling to fine-tune print quality

[...] When I ran through the diagnostic portion of the process, I found that rather than extruding 100mm of material - I only got 50mm! Exactly 50mm, actually. No wonder I was seeing under-extrusion. I was only spitting out half of the filament expected! I went through the calculations but haven't issued the M92 command to change the default behavior of the printer yet. Instead, I reprinted the badge and tuned flow to 200% and viola. I got the much better results I had at the start (see picture). Now I'm in the ballpark and can work on finer grade tuning rather than just trying to get basic results!Peter, glad to read that you got this figured out. I read this post and was happy someone figured the issue out. I had to search through my post history to realize you were the guy with the problem!