Inconsistent 'finished side' of models
I am printing these pieces upside down so that I can have the smoother bedside finish on top. It looks really nice, sometimes. What I can't figure out is why the finish is inconsistent. Two out of three prints have a very smooth nice looking matte finish. But typically one of the three will have large gradient regions where there are noticeable grooves and an 'ugly' shiny finish to it.
Leading up to this, I spent a decent amount of time printing multiple test patterns to really dial in my Z-adjust and mesh bed level correction. That is how I got to a point where I could actually achieve that nice matte finish at least 2 out of 3 times. (Never got that finish before the extra calibration.) So now I can get it often, but why inconsistently? With same gcode, same filament, same temp settings, same ambient room temp (no fans)...and I clean the bed with isopropyl after every print. Many of these prints are done back to back, and I'll get a 'bad' one right after a perfect one.
I will also mention that the location of bad regions is also not consistent. If it were alway bad in one quadrant, I would assume my bed level correction still needed tweaking. However the orientation of the imperfections change on every print, so I'm thinking it must be something other than a bed level issue?
Any ideas as to what I can tweak in order to consistently get the same finish?
Thanks in advance.
Re: Inconsistent 'finished side' of models
Apologies for the bump, but could really use some advice on this one...
Thanks.
Re: Inconsistent 'finished side' of models
I'm having similar slightly inconsistent Z issues from day to day, especially the first print of the day.
Honestly I'm currently putting it down to metal parts in the printer itself having slightly different lengths when I wake up (14C ambient in the room) to later in the day (22C) - things that will slowly heat up as opposed to the bed. I would hate for the printer itself to be drifting Z between reboots, and cant really see why/how it would.
The texture you like seems to be very close to not being squished at all, so I expect that to be very hard to dial in and still have an adhering 1st layer - I think your window of tolerance to get that result is very very small.
Re: Inconsistent 'finished side' of models
I don't think my photos conveyed that properly then, because the texture I'm talking about is when the print lays very flat on the bed, well squished, with full contact on the bed surface. When I print the Z test objects on thingiverse that were linked to in another thread, I get excellent consistent results after calibration. Those single layer only test prints measure around .23mm thick with a digital caliper. The test print that covers the whole bed has almost perfect consistency and flatness in all areas of the bed. (pic)
But when I print the black model in the other pics though, I only get that 100% surface contact 2 out of 3 times. The 'bad' areas I'm referring to are not fully contacting the bed, the material is pulled away from the bed in grooves and ridges. But always in different areas of the bed.
I guess what I haven't considered so much is the filament itself. The filament I calibrated my bed with is the PRUSA silver PLA. The black prints are MonoPrice PLA. Could this black filament be causing inconsistent lay down and texture?
Re: Inconsistent 'finished side' of models
Ah, I think I see what you mean, I've just been printing a large "tray" that I get similar things with. Any slight nozzle "drag" has a chance to cause a mess across an area of the print. I kept nudging my Live Z up until it was mostly fine (although the bottom of the tray is not going to be visible for me).
A different fill pattern may help if that's acceptable visually.
For me, the "texture" of the powder coated sheets making this problem "go away" is highly desirable, having seen it on the MK3 printed parts.
Re: Inconsistent 'finished side' of models
Filament diameter varies slightly over length, some brands more than others. This will cause variation in extrusion.
One thing you could try, since you care about that first layer, is in slic3r, adjust the first layer width to overextrude more. In print settings / advanced, change first layer to 115% or 0.45 or similar.
Re: Inconsistent 'finished side' of models
Thanks, I will give that a shot. Will also compare against other filaments to see if that changes the rate of success.
Re: Inconsistent 'finished side' of models
Definitely check with some other filament. I print mostly with Inland, and it tends to be very consistent from one roll/color to the next, except for this one roll of red. It prints totally different from the others, it slightly under extrudes, and it is a flaming mess at 210-215, it has to be printed at 195-200. It also requires a Z-height tweak.