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JLTX
 JLTX
(@jltx)
Reputable Member
poor print quality

I got my MK3 finally and assembly was so much easier, took 1/3 the time of MK2S. Final calibration went perfectly the first time with no hitch and very tight tolerances. And DAMN that thing is quiet!

But so far the print quality is quite poor, much worse than MK2S. The surface quality on MK2S, both vertical and horizontal, was nearly flawless but MK3 prints are very rough with ringing and what looks like over and under extrusion. I am just printing the demo parts but will move to more of my own objects for testing. Is the firmware still being refined? Ideas on Slic3r settings to improve the situation?

Publié : 20/12/2017 2:06 pm
Impruve
(@impruve)
Estimable Member
Re: poor print quality

Can you show us pictures please??

Too much ringing can be because of the belt tensions... did you check the Belt Status on the printer?

If all is well in that regard.. try slowing down a bit the outer-most perimeter, it makes a huge difference and you wont see that much of an impact on final print time.

The extrusion multiplier probably needs to be dialed in more accurately. Do it on the slicer... if you see that you need to dial more than 10% (+ or -) then you probably should do it on the firmware

Publié : 20/12/2017 6:22 pm
RotaryDane
(@rotarydane)
Eminent Member
Re: poor print quality

Pictures would be a very big help.. And print settings you're using.. And wether or not you've gone over and re-tightened everything.
As Leonardo mentioned, belt tension can play a huge role in ringing.

Publié : 20/12/2017 6:26 pm
JLTX
 JLTX
(@jltx)
Reputable Member
Topic starter answered:
Re: poor print quality

I'll try to get some pictures. I've checked all the belts, PID tune, and the diags are clean. I still need to dial in the extrusion multiplier. I was printing the demo prints so I assumed they chose good slicer settings for MK3. I have many of my own models to slice and I'll try slowing it down. It's just a contrast to the MK2S which on the very first print was amazing.

Publié : 21/12/2017 1:57 am
Impruve
(@impruve)
Estimable Member
Re: poor print quality

Under the support tab on the printer.... there is a option called Belt Status.

What values do you have there??

If the values are above 240, you're on the loose side of the belt tension (ringing ringing).... The manual says that values up to 280 are still "good" but i would try to get as close as possible to 240... even a bit lower since they say values down to 200 are also "good".

Publié : 21/12/2017 1:12 pm
JLTX
 JLTX
(@jltx)
Reputable Member
Topic starter answered:
Re: poor print quality


Under the support tab on the printer.... there is a option called Belt Status.

What values do you have there??

If the values are above 240, you're on the loose side of the belt tension (ringing ringing).... The manual says that values up to 280 are still "good" but i would try to get as close as possible to 240... even a bit lower since they say values down to 200 are also "good".

Good tip. Belt self-check passed, but status shows X=202 and Y=260. I will try to even those out.

BTW, I am definitely over-extruding. There is another thread describing same problems I am seeing. I have backed off about 5% and will run more tests.

Thanks.

Publié : 21/12/2017 2:53 pm
Impruve
(@impruve)
Estimable Member
Re: poor print quality



Under the support tab on the printer.... there is a option called Belt Status.

What values do you have there??

If the values are above 240, you're on the loose side of the belt tension (ringing ringing).... The manual says that values up to 280 are still "good" but i would try to get as close as possible to 240... even a bit lower since they say values down to 200 are also "good".

Good tip. Belt self-check passed, but status shows X=202 and Y=260. I will try to even those out.

BTW, I am definitely over-extruding. There is another thread describing same problems I am seeing. I have backed off about 5% and will run more tests.

Thanks.

That Y is fine... X should be better (will give you more work... you have to take off the back plate =/)...

Tell us how it goes and if you improved print quality.

Publié : 21/12/2017 6:37 pm
JLTX
 JLTX
(@jltx)
Reputable Member
Topic starter answered:
Re: poor print quality




Under the support tab on the printer.... there is a option called Belt Status.

What values do you have there??

If the values are above 240, you're on the loose side of the belt tension (ringing ringing).... The manual says that values up to 280 are still "good" but i would try to get as close as possible to 240... even a bit lower since they say values down to 200 are also "good".

Good tip. Belt self-check passed, but status shows X=202 and Y=260. I will try to even those out.

BTW, I am definitely over-extruding. There is another thread describing same problems I am seeing. I have backed off about 5% and will run more tests.

Thanks.

That Y is fine... X should be better (will give you more work... you have to take off the back plate =/)...

Tell us how it goes and if you improved print quality.

Yes, I hate the new x-carriage design with back plate. But I was planning to tighten up the Y since it is looser. You think I should loosen X?

Publié : 21/12/2017 8:36 pm
ryan.p6
(@ryan-p6)
Active Member
Re: poor print quality

+1 on the MK3 print quality being poor.

I also have a MK2S that prints beautifully but I can't get my MK3 to print anything even remotely close in quality to what comes off my MK2S. Some notes that may be helpful:
- Passed self test
- Passed XYZ calibration with all axis perpindicular
- Checked extruder calibration and it was perfect out of the box - commanded it to extrude 100mm of filament and it consumed exactly 100mm of filament. I'm using good quality filament as well (Matterhackers PRO) that I always dry in the oven before using (4-6 hours at 170F).
- Checked heatbed and hot end temps with my fluke IR thermometer - both were within a degree or two which is within the uncertainty of the fluke
- I think the belt tensions are good. It says X is 245 and Y is 281 (perhaps a tad on the high side but would that explain garbage prints?)

As I've been getting failed or otherwise horrible looking prints I've played around with a bunch of different things. I've messed with the extruder tension a bit and that doesn't seem to make any difference (what depth should the tension screw be notionally set to anyway?). I've varied the hot end and bed temp a bit and that didn't seem to make much of a difference. I varied print speed and while I'd say the quality improved but didn't get me to usable parts.

Another thing I tried was to mount a dial indicator to the hot end and then with the steel sheet installed i manually commanded the hot end around the build plate and I got excited for a second that I found the problem. Not only was the X axis misaligned (the delta height between the left and right side of the plate was nearly 0.3mm!!!) but I also found that the plate isn't "flat". There was a front-to-back delta height on the left side of ~0.07mm but down the middle there was a high spot in the center and low spots in the front/back and the opposite was the case down the left side (low spot in the middle and high spots in the left front and left rear corners). Either way I decided to try correcting the gross right-to-left issue manually and then apply some minor bed level corrections to try to null out the much less severe front-to-back issue. I powered the machine off (with the dial indicator still on the hotend) and then repeated the left-to-right movements across the center of the build plate while making very minor adjustments to the right side leadscrew until the X axis was nearly perfectly aligned with the plate. I then powered the machine back on, and applied some minor 10um and -10um bed level corrections to null out the average front-to-back misalignment.

I then started prints on both the MK2S and the MK3 at the same time - exact same part, same material, both sliced in slic3r with the exact same settings for temperatures, speeds, and basically everything else. And note that at this point I had set the max speed for EVERYTHING to 40mm/sec and max acceleration on all axis to 800mm/sec^2. The first layer on the MK3 looked significantly better than every other print attempt so I was encouraged. Unfortunately, I checked on the prints after an hour or so and while the MK2S part looked stunningly perfect the MK3 print was already starting to look crappy. After a couple more hours I decided not to waste the filament because the MK3 part looked like a child was melting a crayon and smearing it all over the part.

At this point I don't know what to do/adjust nor do I understand how I can be getting perfect prints on the one/older machine and unusable garbage on the MK3. Help?!?!?!

I know I need to post some pictures so I'll try to get some shortly.
.

Publié : 21/12/2017 9:50 pm
Impruve
(@impruve)
Estimable Member
Re: poor print quality



Good tip. Belt self-check passed, but status shows X=202 and Y=260. I will try to even those out.

BTW, I am definitely over-extruding. There is another thread describing same problems I am seeing. I have backed off about 5% and will run more tests.

Thanks.

That Y is fine... X should be better (will give you more work... you have to take off the back plate =/)...

Tell us how it goes and if you improved print quality.

Yes, I hate the new x-carriage design with back plate. But I was planning to tighten up the Y since it is looser. You think I should loosen X?

I made a few tests...

I almost completely loosen the Y belt... I had values of 260ish... with the belt loose it jumped to 290.. so I assume a +240 value will be loose and -240 will be tight...

So in theory if you have 200 in the X you should loosen the belt..... I will make more tests tonight.

Publié : 21/12/2017 10:08 pm
Jan Pichrt
(@jan-pichrt)
Membre
Re: poor print quality

Could Joseph Prusa say something about this? Bcs. this is wide user problem... not single user. I have print quality issues too... 🙄 pretty shitty quality even with presliced things from SD card...

Nice to build printer faster, buth with this output is printer useless and waste of money. I hope that is it only Slicer/FW/print profile problem... 😥

Publié : 21/12/2017 10:15 pm
ryan.p6
(@ryan-p6)
Active Member
Re: poor print quality

Hmm - I think that's different than what I'm seeing. My Y belt is 281 and "feels" tighter than my X belt at 245. Also, I had a lot of trouble getting any kind of tension on the X belt as it kept slipping in the mount. I'd rotate the motor with a little bit of resistance and would hear it pop as the teeth were slipping in the mount. I should also have noted that in my pictures - after the first complete failure print I tried to increase tension on the X belt because it "felt" loose to me (this was before I realized you could check belt tension in the interface) and I suspected it may have slipped during the print. I was unable to get any kind of tension on the belt without it slipping so ultimately I had to cut up a business card and slip the pieces into the mount as shims to prevent the belt from slipping. In all these cases the belt was fully slipped into the mount so it appear to me that I got defective parts or Prusa needs to reduce the clearance slightly in the part. For reference my MK3 X-carriage tension still feels a little less than the MK2S but based upon my experience it feels "tight enough".

Publié : 21/12/2017 10:20 pm
Impruve
(@impruve)
Estimable Member
Re: poor print quality


+1 on the MK3 print quality being poor.

I also have a MK2S that prints beautifully but I can't get my MK3 to print anything even remotely close in quality to what comes off my MK2S. Some notes that may be helpful:
- Passed self test
- Passed XYZ calibration with all axis perpindicular
- Checked extruder calibration and it was perfect out of the box - commanded it to extrude 100mm of filament and it consumed exactly 100mm of filament. I'm using good quality filament as well (Matterhackers PRO) that I always dry in the oven before using (4-6 hours at 170F).
- Checked heatbed and hot end temps with my fluke IR thermometer - both were within a degree or two which is within the uncertainty of the fluke
- I think the belt tensions are good. It says X is 245 and Y is 281 (perhaps a tad on the high side but would that explain garbage prints?)

As I've been getting failed or otherwise horrible looking prints I've played around with a bunch of different things. I've messed with the extruder tension a bit and that doesn't seem to make any difference (what depth should the tension screw be notionally set to anyway?). I've varied the hot end and bed temp a bit and that didn't seem to make much of a difference. I varied print speed and while I'd say the quality improved but didn't get me to usable parts.

Another thing I tried was to mount a dial indicator to the hot end and then with the steel sheet installed i manually commanded the hot end around the build plate and I got excited for a second that I found the problem. Not only was the X axis misaligned (the delta height between the left and right side of the plate was nearly 0.3mm!!!) but I also found that the plate isn't "flat". There was a front-to-back delta height on the left side of ~0.07mm but down the middle there was a high spot in the center and low spots in the front/back and the opposite was the case down the left side (low spot in the middle and high spots in the left front and left rear corners). Either way I decided to try correcting the gross right-to-left issue manually and then apply some minor bed level corrections to try to null out the much less severe front-to-back issue. I powered the machine off (with the dial indicator still on the hotend) and then repeated the left-to-right movements across the center of the build plate while making very minor adjustments to the right side leadscrew until the X axis was nearly perfectly aligned with the plate. I then powered the machine back on, and applied some minor 10um and -10um bed level corrections to null out the average front-to-back misalignment.

I then started prints on both the MK2S and the MK3 at the same time - exact same part, same material, both sliced in slic3r with the exact same settings for temperatures, speeds, and basically everything else. And note that at this point I had set the max speed for EVERYTHING to 40mm/sec and max acceleration on all axis to 800mm/sec^2. The first layer on the MK3 looked significantly better than every other print attempt so I was encouraged. Unfortunately, I checked on the prints after an hour or so and while the MK2S part looked stunningly perfect the MK3 print was already starting to look crappy. After a couple more hours I decided not to waste the filament because the MK3 part looked like a child was melting a crayon and smearing it all over the part.

At this point I don't know what to do/adjust nor do I understand how I can be getting perfect prints on the one/older machine and unusable garbage on the MK3. Help?!?!?!

I know I need to post some pictures so I'll try to get some shortly.
.

That looks really awful... I still don't have enough print time to have a opinion about print quality....

I believe with a little tweaking we can get perfect prints...

Have you calibrated PID? Are your temperatures stable? Did you try another filament?

Publié : 21/12/2017 10:25 pm
ryan.p6
(@ryan-p6)
Active Member
Re: poor print quality


Could Joseph Prusa say something about this? Bcs. this is wide user problem... not single user. I have print quality issues too... 🙄 pretty shitty quality even with presliced things from SD card...

Nice to build printer faster, buth with this output is printer useless and waste of money. I hope that is it only Slicer/FW/print profile problem... 😥

Agree with this - it would be great to hear from Josef on this. I bought the machine to double my print output but I'm not even using it because I'm getting nothing but failed prints or otherwise terrible quality prints. The machine is noticeably quieter and the bed upgrade seems like it could be awesome if the machine worked but at this point I'm wishing I bought another MK2S and then did the 2.5 upgrade for the heatbed and upgraded PINDA.

Publié : 21/12/2017 10:27 pm
kelchm
(@kelchm)
Eminent Member
Re: poor print quality

Those of you that are having issues, what version of Slic3r are you using? I'd recommend making sure you're on at least 1.38.4, which you can download here.

Publié : 21/12/2017 10:39 pm
Bigdogbro1
(@bigdogbro1)
Estimable Member
Re: poor print quality

Does Simplify3D have the profile available for the MK3 yet and can it be loaded into an existing Simplify3D application on my PC?

Any links for the profile?

MK3 Kit, Designed, built 4x4 CNC Plasma Cutting Table, Motorcycles Bigdogbro's Adventures
http://www.youtube.com/channel/UC5djrxBeeOKB9_6rHnn6G8A

Publié : 21/12/2017 10:51 pm
JLTX
 JLTX
(@jltx)
Reputable Member
Topic starter answered:
Re: poor print quality


Those of you that are having issues, what version of Slic3r are you using? I'd recommend making sure you're on at least 1.38.4, which you can download here.

I am using the official 2.0 driver version which is 1.37.2-prusa. I'm surprised they are already that far ahead on TOT. I'll grab that and try.

Publié : 21/12/2017 11:22 pm
JLTX
 JLTX
(@jltx)
Reputable Member
Topic starter answered:
Re: poor print quality

So I tried an experiment and printed the Marvin gcode from the MK2 directory. This printed much cleaner, almost the same as my MK2S print. There was no ringing or blobbing. The MK3 gcode produced a gnarly mess. I am diff'ing the gcode now to find the differences.

Publié : 21/12/2017 11:25 pm
mikola.z
(@mikola-z)
Eminent Member
Re: poor print quality

Properly assembled MK3 prints at least as good as MK2S, I would even say a hair bit better, not to mention the faster prints.

So this is most likely a PEBCAK (Problem Exists Between Chair And Keyboard). Or the unlikely case of some faulty part.

Publié : 21/12/2017 11:34 pm
Impruve
(@impruve)
Estimable Member
Re: poor print quality


Properly assembled MK3 prints at least as good as MK2S, I would even say a hair bit better, not to mention the faster prints.

So this is most likely a PEBCAK (Problem Exists Between Chair And Keyboard). Or the unlikely case of some faulty part.

Thats to be expected =).

The question is... did you get better results right out of the box with the pre-sliced models or the default profiles?

Actually im not surprised those need tweaking.. was expecting it already.

Publié : 21/12/2017 11:45 pm
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