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Haven't had a good print since I got my mk3s in December  

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Drekly
(@drekly)
Active Member
Haven't had a good print since I got my mk3s in December

I feel like I wasted my money.

I set the machine up correctly, set my first layer just fine, but every print comes out looking terrible. Even the test prints that come pre-loaded on the card.

I emailed Prusa support, and they just say 'split the model up' but that doesn't help if the quality is terrible already. They haven't really said anything that will improve prints other than point to support documentation I'm already following.

Every print is stringy and gooey. I've run temp towers, adjusted flow, changed e-steps, nothing seems to help. I've bought new nozzles, new heatbreaks, new heat cartridges, new heaterblocks, new filament. 

I'm talking to the guys in the '3d printed tabletop' discord channel and they've been trying to troubleshoot it now for an entire month without an end in sight. 

I spent so much money on this printer thinking it would be high quality, then I've spent loads more on extra parts and troubleshooting, not to mention the hundreds of hours I've spent trying to fix it.

I'm really unhappy with my printer and I don't know what to do. 

This topic was modified 4 years ago 2 times by Drekly
Posted : 16/03/2020 2:43 am
bobstro
(@bobstro)
Illustrious Member
RE: Haven't had a good print since I got my mk3s in December

It would help immensely if you'd post a few pictures. Also, save your project 3MF file with a typical part loaded with your settings, zip it up and upload it here so we can check out your settings.

Support works best via online chat. Access after logging into the web store.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 16/03/2020 1:16 pm
Drekly
(@drekly)
Active Member
Topic starter answered:
RE: Haven't had a good print since I got my mk3s in December

Of course,

So I bought the printer mostly for miniatures, so that's what I've been struggling most with. I know I could have bought an SLA, but my house does not have the necessary ventilation, and I imagined a high quality FDA printer and a 0.25 nozzle would be close in quality.

However, no matter what I print it turns out looking wrong, or bad quality. This is just compounded by the fact I bought the machine to print detailed objects.

Here is an example of a few things I've been trying to print and always had less than satisfactory results:

 

Test Cube: https://imgur.com/a/0SGWrnB

Heroforge Paladin Model: https://imgur.com/a/YEbvzFQ

An earlier print of the Same model: https://imgur.com/a/8r31uCa

The pre-sliced frog test that comes packaged with the prusa mk3s: https://imgur.com/a/v8vKkWE

Posted : 16/03/2020 5:28 pm
rmm200
(@rmm200)
Noble Member
RE: Haven't had a good print since I got my mk3s in December

Did you build it from a kit or buy it prebuilt?

Did you install the .025 nozzle yourself?

What build plate, what filament, what bed and nozzle temperature?

Could you post a picture of a calibration square so we can see how it looks? Get one from:

https://forum.prusa3d.com/forum/original-prusa-i3-mk3s-mk3-assembly-and-first-prints-troubleshooting/life-adjust-z-my-way/

Export your model from PrusaSlicer as a .3mf file. Post here as a zip. PrusaSlicer problems we can identify. Not so sure about Cura.

This post was modified 4 years ago by rmm200
Posted : 16/03/2020 8:33 pm
rmm200
(@rmm200)
Noble Member
RE: Haven't had a good print since I got my mk3s in December

This is a fair example of what your machine is capable of:

https://forum.prusa3d.com/forum/english-forum-awesome-prints-hall-of-fame/first-kilometer-in-my-3d-print-journey/

 

Posted : 16/03/2020 8:39 pm
Drekly
(@drekly)
Active Member
Topic starter answered:
RE: Haven't had a good print since I got my mk3s in December

@robert-rmm200

This is what I was hoping for when I bought the printer. It looks beautiful. amazing models and fantastic prints. I am NOWHERE near that

Prusa support literally told me I should have bought an SLA printer if I wanted that level of quality! 

I am currently using a 0.4 nozzle again, but yes I did install the 0.25 myself when it arrived, and had the same issues as shown in my images.

It was a MK3s kit, with the PEI build plate. I have used many temperatures but nothing seems to change the print quality. For the current filament I have settled on 200c, but have tried as low as 180 and as high as 220. 

I have used the prusament galaxy silver that came with the machine, when this looked bad, I tried some XYZ filament from my old machine. When it still looked bad, I ordered new PLA from 3dfilaprint, which still gives the same results.

Unfortunately I am dealing with cura, as prusaslicer doesn't have very good supports for smaller models like miniatures. Although print quality does not change depending on the slicer anyway.

 

Here is my result with the calibration square. I raised it higher for the second half, but I think it was good where it was at -1.210

https://imgur.com/a/pT48vaD

Posted : 16/03/2020 11:42 pm
rmm200
(@rmm200)
Noble Member
RE: Haven't had a good print since I got my mk3s in December

Your Z - and adhesion both look very good.

I do question why Z is so negative. I am more used to values in the -0.850 to -0.950 range. Not saying yours is wrong - but it is unusual.

You might do a quick check on PINDA height. Paper on the print bed, lower nozzle until it touches.

A zip tie (thin tip) should just slip under PINDA.

Stringing: Stringing increases as temp goes up. Conversely, it gets less as tip temp goes down. But back pressure goes up.

Using the .40 nozzle, lower the head temp 10 degrees at a time - and observe.You should find a point where filament still flows - but does not string.

The .25 nozzle is too prone to jam anyway to experiment with unless this helps.

Posted : 17/03/2020 3:27 am
bobstro
(@bobstro)
Illustrious Member
RE: Haven't had a good print since I got my mk3s in December
Posted by: @sam-g-pascoe

[...] Unfortunately I am dealing with cura, as prusaslicer doesn't have very good supports for smaller models like miniatures. Although print quality does not change depending on the slicer anyway.

Cura is a fine slicer, but PrusaSlicer is really tuned for the Prusa printers. I'm able to get decent miniatures on my Mk3. Here's a sample using Inland PLA:

The key is to start with less ambitious settings and refine them as you go. This isn't a perfect print by any stretch of the imagination, but it's better than most of the metal figures I played with 10 years ago. It looks a lot better on the table than blown up 400% here. Here's what I'm doing:

  • 0.25mm nozzle
  • 0.15mm layer height
  • 0.25mm contact z distance
  • 3mm pattern spacing
  • 4 interface layers
  • 0.2mm interface pattern spacing
  • No interface loops
  • 75% XY separation between object and its support

Try tilting the model back 45 degrees or rotating it to a degree that reduces the need for support.

Some filaments tend to string a bit more than others. Here's another with the same settings using Paramount PLA:

I'd suggest starting with some simpler and faster prints to help narrow down your issue. That degree of stringing usually indicates one or more problems with:

  • Filament moisture absorption. If you're getting the same results with 2 different PLA filaments, this is unlikely. Other filaments are more prone to the problem.
  • Over-extrusion. If you're using a Prusa filament preset with Prusa filament, less likely to be an issue. If using other filament, be sure to calibrate your extrusion multiplier for that filament.
  • Excessive temperatures. Print as cool as you can. Try 190C with PLA.
  • Use cooling. It is usually set to 100% for PLA. Be sure your part cooling is working correctly.
  • Do a PID calibration at your normal PLA printing temperature. This will help keep the temperature consistent.

Work on the basics, then you can work towards smaller layer heights and more refined settings.

 

 

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 17/03/2020 5:23 am
Drekly
(@drekly)
Active Member
Topic starter answered:
RE: Haven't had a good print since I got my mk3s in December

@robert-rmm200

I do use a 0.4 nozzle, I want the machine to start printing correctly before I try the 0.25 again. 

I am printing pretty low temperatures with the same results.

Would you like any particular test model to demonstrate 2 different temperatures?

Posted : 17/03/2020 9:20 pm
Drekly
(@drekly)
Active Member
Topic starter answered:
RE: Haven't had a good print since I got my mk3s in December

@bobstro

Prints look bad from both Cura and prusaslicer, and even the default g-code with the filament that was packaged with the machine.

I'm not being ambitious, I'm just printing with defaults and trying to get a good print, and I've been over the basics over and over for 3 months.

The discord group has tried to help make custom profiles, but nothing seems to fix the issue.

This model was printed at 45 degrees.

I have tried multiple filaments, and even bought another brand new one today, and new nozzles, to find it has the exact same issue. 

I have the issue with prusament, and with other filaments I have tuned the extrusion multiplier using a two decimal place digital calipers and a hollow cube.

I have printed from 180 to 220 with the same problems. 

The fans always run at 100% except the first layer.

I have not done a PID tuning; it shouldn't solve a problem that has been present for months at varying temperatures, but I'm doing one now. 

This post was modified 4 years ago by Drekly
Posted : 17/03/2020 9:27 pm
Drekly
(@drekly)
Active Member
Topic starter answered:
RE: Haven't had a good print since I got my mk3s in December

@bobstro

Apologies, that link is wrong and my edit time ran out

This is the 45 degree test

Posted : 17/03/2020 9:35 pm
Steve
(@steve-5)
Trusted Member
RE: Haven't had a good print since I got my mk3s in December

Just to play devil's advocate a little... I looked at your first layer coupon picture and I actually think you are still too high at -1.210 as I see gaps near the edges in several places.  In addition, over the first half of the print it appears that there is some not insignificant variation in extrusion thickness, are you using 7x7 mesh bed leveling? If you are not then I would strongly recommend switching to that setting (using 5 samples/point).  I concur with Robert's recommendation to re-check your PINDA height as well as live-Z numbers more negative that -1.00mm are unusual.  Obviously if you re-set the PINDA height you will need to go through the live-Z process anew but I think it could be worthwhile.

Finally, I will put in a plug for bobstro here and recommend that you check out his notes at his website for lots of great, useful information about tuning your printer for the best results.  I personally would begin with the PINDA warmup procedure before mesh bed leveling.  I have been using a slightly modified version of his procedure for many weeks now and have experienced phenomenal consistency in first layer characteristics of all of my prints regardless of the filament used.

Hang in there, you've seen what the printer is capable of, now we just need to get you to the same place!

Regards,

Steve

Posted : 17/03/2020 11:03 pm
Drekly
(@drekly)
Active Member
Topic starter answered:
RE: Haven't had a good print since I got my mk3s in December

@steve_g

I Changed my Nozzle yesterday and my Z-level is now at -0.563

Over the past 3 months it has been adjusted dozens of times. Would the first layer being cleaner change the entire print?

I believe the strange number this time is due to the sensor. One day last week it just stopped working and I was getting a Z axis length errors. It seemed like the PINDA sensor just wasnt detecting and triggering from the distance it was set at anymore. (zip-tie, like it says in the manual) so I had to lower it drastically before it 'saw' the bed. After this adjustment and re-calibration, prints looked identical, so I didn't think it was an issue. 

After fitting the new nozzle, it now works at zip-tie distance again - perhaps it was dirty or just fussy that day! 

PINDA warm up sounds interesting, does this just warm the sensor to 35c before beginning, to ensure it's reading are more correct and consistent? I am reading here, is this correct? 

Other than first layer calibration (which has been done many many times, with many parts and filaments) what would be my next steps?

 

 

 

Posted : 18/03/2020 1:29 pm
DJ
 DJ
(@dj-6)
Trusted Member
RE: Haven't had a good print since I got my mk3s in December

@sam-g-pascoe

IIRC the Pinda sensor accuracy and repeatability suffers if it is too far from the target inside the build plate. This is a possible reason for the empirical wisdom of having the live Z readings more positive than -1.0 or so. 

DJ

Posted : 18/03/2020 2:24 pm
Steve
(@steve-5)
Trusted Member
RE: Haven't had a good print since I got my mk3s in December
Posted by: @sam-g-pascoe

@steve_g

I Changed my Nozzle yesterday and my Z-level is now at -0.563

Over the past 3 months it has been adjusted dozens of times. Would the first layer being cleaner change the entire print?

Wow, that is a larger difference than I would have expected from just a nozzle change.  No, the first layer being cleaner will not change the entire print, it just ensures that you have the requisite good bed adhesion to avoid other problems (blob of death).  I apologize for not being more clear about my intention in my earlier post. 

I believe the strange number this time is due to the sensor. One day last week it just stopped working and I was getting a Z axis length errors. It seemed like the PINDA sensor just wasnt detecting and triggering from the distance it was set at anymore. (zip-tie, like it says in the manual) so I had to lower it drastically before it 'saw' the bed. After this adjustment and re-calibration, prints looked identical, so I didn't think it was an issue. 

After fitting the new nozzle, it now works at zip-tie distance again - perhaps it was dirty or just fussy that day! 

PINDA warm up sounds interesting, does this just warm the sensor to 35c before beginning, to ensure it's reading are more correct and consistent? I am reading here, is this correct? 

It is possible that the PINDA is defective although as simple as they are I would think it unlikely.  Yes, the purpose of the PINDA warmup process is to ensure consistent readings.  The nature of the sensor design makes it sensitive to temperature so at different sensor temperatures it will give different readings.  Obviously the most critical readings are for mesh bed leveling so by warming the sensor to a known, consistent temperature prior to performing the measurements you get a very consistent, repeatable measurement of the heatbed "contour".  The PINDA warmup process is accomplished by adding customized startup g-code to your slicer for inclusion in all print g-code files.

Other than first layer calibration (which has been done many many times, with many parts and filaments) what would be my next steps?

Once you have a good, consistent first layer you are likely now into tuning for your particular filaments. and some of the other suggestions that Bobstro made in his earlier post.  I will add a shameless plug here for Bob, he has complied copious extremely useful notes on many aspects of 3d printing (including filament tuning and PINDA warmup) at the website link provided in his signature. I strongly recommend reading them for tips and tricks to get the best from your printer.

Regards,

Steve

Posted : 18/03/2020 4:34 pm
bobstro
(@bobstro)
Illustrious Member
RE: Haven't had a good print since I got my mk3s in December
Posted by: @sam-g-pascoe

[...] Over the past 3 months it has been adjusted dozens of times. Would the first layer being cleaner change the entire print?

Any warping would have impacted higher layers. Other than that, unless the 1st layer is distorted, it shouldn't impact higher layers.

[...] PINDA warm up sounds interesting, does this just warm the sensor to 35c before beginning, to ensure it's reading are more correct and consistent? I am reading here, is this correct? 

Yes, that is correct. Most of that page describes making one-time changes and saving results to firmware. I've implemented the print-time approach described under the alternate approach heading. My thinking is that this both warms the bed up and also ensures it will work on any printer.

Other than first layer calibration (which has been done many many times, with many parts and filaments) what would be my next steps?

You're getting pretty horrendous results, far more than typical "stringing".  I've got notes on how I've dealt with stringing here, but I'm not sure they'll be of much use in your situation. If you haven't already, I'd back up layer heights to 0.15mm until you get reasonable results, then back down to finer levels. Printing at 0.1mm layer heights or smaller gets tricky, especially if you've got some fundamental issue going on. Debug at 0.15 or even 0.2mm layer heights, get those looking good, then go for broke on detail.

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 18/03/2020 7:04 pm
rmm200
(@rmm200)
Noble Member
RE: Haven't had a good print since I got my mk3s in December

Just a general comment on nozzle diameters.

These printers work by pushing melted filament through a hole.

The smaller you make that hole, the more pressure it takes and the easier it will get obstructed. 

Filled filaments make this worse - big time. I would not use carbon or wood filled filaments in a really small nozzle.

And with a small nozzle, be really scrupulous about cold pulls and cleaning filament. Keep those stray bits away from the hole.

I really don't like dealing with filament jams... But that is just me.

 

Posted : 18/03/2020 7:16 pm
Drekly
(@drekly)
Active Member
Topic starter answered:
RE: Haven't had a good print since I got my mk3s in December

@robert-rmm200

Yes, after 2 prints back in January at 0.25 I realised my printer wasn't set up well enough to even attempt any more, so I quickly changed back to 0.4. 

@bobstro

Thanks so much for the extra details about that link, I've incorporated it, and my intro code now looks like this:

G21 ; set units to millimeters
G90 ; use absolute positioning
M82 ; absolute extrusion mode
G28 W ; home all without mesh bed level
M104 S0 ; Turn off all heaters
M140 S0 ; Turn off all heaters
M106 S255 ; turn on fan
G0 Z100 ; PINDA cooling position
M860 S30 ; wait until PINDA is <= 30C
M107 ; turn off fan
M104 S{material_print_temperature_layer_0} ; set extruder temp
M140 S{material_bed_temperature_layer_0} ; set bed temp
M190 S{material_bed_temperature_layer_0} ; wait for bed temp
M109 S{material_print_temperature_layer_0} ; wait for extruder temp
G0 X50 Y50 Z0.15 ; this is a good PINDA heating position
M860 S35 ; wait until PINDA is >= 35C
G28 W ; home all without mesh bed level
G80 ; mesh bed leveling
G92 E0.0 ; reset extruder distance position
G1 Y-3.0 F1000.0 ; go outside print area
G1 X60.0 E9.0 F1000.0 ; intro line
G1 X100.0 E21.5 F1000.0 ; intro line
G92 E0.0 ; reset extruder distance position

Hopefully that looks correct.

I'm currently printing everything at 0.16mm by recommendation of someone from discord, rather than 0.15mm due to esteps.

You mention that my prints look bad but the link you posted may not help. That sounds worrying! Do you have a suggestion of what will help? I will of course read through the page and do everything I can to follow your advice there.

 

 

Posted : 18/03/2020 11:55 pm
bobstro
(@bobstro)
Illustrious Member
RE: Haven't had a good print since I got my mk3s in December
Posted by: @sam-g-pascoe

[...] M82 ; absolute extrusion mode

I usually have M83 for relative extrusion mode. If you get any weird extruder movement, check this line.

G28 W ; home all without mesh bed level

Just be aware that with a cold nozzle with any hardened filament hanging down, this may drive the filament into your bed at the homing position. My 1st PEI sheet has a significant divot at that location. That's why the no-ooze warmup is used to soften any dangling filament a bit so it'll bend away on homing.

M104 S0 ; Turn off all heaters
M140 S0 ; Turn off all heaters
M106 S255 ; turn on fan
G0 Z100 ; PINDA cooling position
M860 S30 ; wait until PINDA is <= 30C
M107 ; turn off fan

This will turn off everything and wait for the PINDA temp. I find that between prints, the PINDA has usually cooled off to well below 35C, so I position the nozzle close to the bed and turn the bed temp up (80C in cold winter months) and wait for the PINDA to warm up. If it's already warm, it will continue on without waiting.

The "official" procedure on github waits for it to cool below 30C, then heats up to 35C but I didn't get much benefit out of doing that.

M860 S35 ; wait until PINDA is >= 35C

Just be aware that when printing PLA, your bed temp may only be 55-65C, so the PINDA can take a very long time to warm up.

I'm currently printing everything at 0.16mm by recommendation of someone from discord, rather than 0.15mm due to esteps.

Those "magic" layer heights are usually based on less capable printers. IIRC, the closest thing to a "magic" layer height is based on 0.0025mm steps, so any value with up to 2 digits after the decimal point is equally good. 0.16mm is fine. Just be wary of Internet advice based on other printers. 

You mention that my prints look bad but the link you posted may not help. That sounds worrying! Do you have a suggestion of what will help? I will of course read through the page and do everything I can to follow your advice there.

Not trying to worry you, but it looks like there's something more than just the usual stringing going on. I'd run some quick basic diagnostic prints (e.g. stringing tests, XYZ cubes) to make sure the basics work before jumping into multi-hour miniature prints.

 

My notes and disclaimers on 3D printing

and miscellaneous other tech projects
He is intelligent, but not experienced. His pattern indicates two dimensional thinking. -- Spock in Star Trek: The Wrath of Khan

Posted : 19/03/2020 4:31 am
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