Print quality dropped significantly after couple of months
 
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Filip Safran
(@filip-safran)
Eminent Member
Print quality dropped significantly after couple of months

Hi,
I have finally managed to recalibrate my Mk2 today after not being able to use it for almost half a year.
I got it in May and had great prints. Mostly aesthetic prints with a few functional (the best was a small wand vlender coupler with cooling fins... Really a small and compact print that still works today)
Had a fire accident at home in July and I couldnt use my printer until today. I tried making a small thin print again and the quality was terrible. I calibrated Z axis with the calibration surface print that was uploaded here quite some time ago. Nice, compact, smooth surface.
But after the firat layer things go south.
Bad adhesion, really rough side walls, oval holes which should have been round... And the final layer is so horrible, nothing overlaps.

I had two terrible prints at 20% infill, 60/40 m/s speed. Third one was slightly better with 50% infill and half the speed. I thought it must have been that the object is total 15 mm high, 48 mm long and its only 2 mm thin so i tried printing the batman logo from sd card.
First layer was great but after a while the tips of wings warped up and the final layer was terrible. Not much overlapping of infill and side wall, not too smooth.

It seems I'm loosing quality with height but I dont know why. What should I do? Try cleaning the nozzle? I havent noticed any underextrusion and i belive if that was the case, first layer would be bad as well.

I can upload my third gcode from today (one that was the best) but since batman came out not too good, im sure i have some hardware problem rather than the settings.

Posted : 14/01/2018 10:15 pm
JoanTabb
(@joantabb)
Veteran Member Moderator
Re: Print quality dropped significantly after couple of months

A picture may help
Regards joan

I try to make safe suggestions,You should understand the context and ensure you are happy that they are safe before attempting to apply my suggestions, what you do, is YOUR responsibility. Location Halifax UK

Posted : 14/01/2018 10:36 pm
JeffJordan
(@jeffjordan)
Member Moderator
Re: Print quality dropped significantly after couple of months


,,,First layer was great but after a while the tips of wings warped up and the final layer was terrible. Not much overlapping of infill and side wall, not too smooth...
.

that's a typical sign of bad first layer adjustment, because the first layer "seems" to be good but it's adhesion is to low.

furthermore: how did you store your filament ?
most of the filaments are hygroscopic and show after a couple of months a bad print success if you don't store them in a special environment (enclosure with a lot of silica gel) or treat the filament in an oven for about 2 hours (@50°C).

by the way: 50% infill is unusually high and rarely recommended.

dem inscheniör is' nix zu schwör...

Posted : 14/01/2018 10:52 pm
Peter L
(@peter-l)
Honorable Member
Re: Print quality dropped significantly after couple of months


that's a typical sign of bad first layer adjustment, because the first layer "seems" to be good but it's adhesion is to low.

Another obvious question: Did you clean the print surface with acetone? Dirt/grime/dust buildup is an obvious possible effect if the printer sits unused for an extended period of time.

Posted : 14/01/2018 10:56 pm
Filip Safran
(@filip-safran)
Eminent Member
Topic starter answered:
Re: Print quality dropped significantly after couple of months

This is the batman logo top layer

Today's print top side (was printed on the side, it's a courtain hanger so it was oriented like that to be stronger in the direction the curtain is going to pull on it)

Bottom layer (support under the worst parts.

Regarding first layer... If it "seems" good but isn't, how can I then know if it is or isn't good? My live adjust Z value is almost the same as before, so I think it should be ok. The printer is on the same surface but it has been moved so I recalibrated it.

Bed was dusted and cleaned with acetone twice and dusted regulary in the past 6 months. So was the entire printer but I did notice some dust in the filament spool.

And unfortunately, the filament was out in the open the whole time, I really didn't pay much attention to it although I know it should be kept in moisture free enviornment. I think that it should produce crackling sounds while heating up if there's excesive moisture inside but all seemed well.

Posted : 14/01/2018 11:29 pm
Filip Safran
(@filip-safran)
Eminent Member
Topic starter answered:
Re: Print quality dropped significantly after couple of months

OK, I've lifted the Z ajdust about ,05 mm and layers seem a lot better now. BUT, I still have a problem with litte cracks occuring between lines of infill(i.e. I'm just printing the Prusa logo, the perimeter was done fine, then it starts printing the first layer infill at a 45°angle. Most of it is good but sometimes there appears a crack in between the lines. As if they do not overlap so well so the connection just snaps).
I unloaded the filament, cleaned the nozzle, loaded the filament, pressed load again so a buttload came out of the nozzle and then tried printing.

Another thing I noticed, and I don't remember this from before... the initial line before printing (when nozzle is cleaned from home after calibration check), how thick should it be and should it be the same thickness throughout the whole length? I'm getting different thickness in that line, so maybe I have a flow issue?

Posted : 15/01/2018 9:10 pm
Filip Safran
(@filip-safran)
Eminent Member
Topic starter answered:
Re: Print quality dropped significantly after couple of months

OK, final update for today so I hope someone will be able to make sense of this, cause I'm at a loss here.

Here are two prints, Prusa logo and today's Batman with live Z adjusted a bit higher than yesterday.

It's looking much better... Issues that now persist are the gaps between infill lines (visible best in the "P" corner of Prusa logo, also there's a closeup of one gap on the bottom layer). In some layers they are better, in some worse. For Prusa I only did the live Z adjsutment.

Batman logo still has the same issue, connecting lines are very visible (printing starts at one line, prints in one direction, then gets back to that line and prints in the opposite direction), corners where it just lays a small are are very smudgy and in the last picture you can see a big warping issue on one of the wings. For Batman I also adjsuted the spring loaded filament idler.

I noticed (maybe I'm imagining things cause i don't know what to look for anymore) that myprints come off the bed a lot easier than they did before. Could the bed have degraded in a way over the last 5-6 months? I hope not.

Please bear in mind that I've only used my Prusa for slightly over a month before stopping using it so I didn't get far with printing techniques and I guess I had much luck in calibrating it the first time around.

Posted : 15/01/2018 10:32 pm
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