One of my printers seems to consistently have worse top layers and I can't figure out why
I've been trying to figure this out for ages, really since I got my 2nd printer. My first MK3 has always had beautiful top layers which were further improved via the nickel/copper nozzle and block and silicone sock and a Sunon cooling fan. So for printers 2 (and now 3, which I just setup in the past few weeks), I did the same thing. Only, for whatever reason, my 2nd printer always seem to have worse top layers than the other 2.
I've tried swapping out nearly everything - though I don't have the + upgrades for it yet it also has a nickel/copper nozzle and block, sock, and the Sunon fan. I also originally had a titanium heatbreak in it. I swapped out the heatbreak back for the original, tried other nozzles, swapped out the heater and therminstor, reset to factory defaults and recalibrated the whole thing, did PID tuning, pretty much everything I could think of. I've even been running some PETG through it just to see if that somehow makes a difference (since I was generally using my first printer for PETG). Seems the same everytime. If I bump up the temps, of course, it helps (to a degree) but it's never the same as my other two printers.
My newest printer has the same mods but I thought I'd try a titanium heatbreak again just to see and, yeah, much like the first printer, it prints awesome top layers! Seems to work well with the same gcode and temp settings no problem.
If there anything else I might be missing, short of selling my 2nd printer and just building a brand new one 😛 I will be rolling out the + changes slowly to my first and second printers (3rd already has it). Oh forgot to mention, they all use reverse bowdens, but I've tried it without and same results.
Ideas?
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
Pictures?
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
One easy to miss feature is if you have a bent heat-break or poorly fitted extruder. It is rather difficult to tell if a heat break is just slightly bent, but a good eye and controlled print of a filled layer examined with a microscope can hint at this type of issue.
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
The only answer I can give without any reference material of any kind is, for you to order 1 more printer, send me the one that's acting up and then by default your 3rd printer will become your 2nd printer and we can hope for the best that new printer (Now the 3rd printer), prints with great top layers.
I'll beat the printer your sending to me into shape and be sure to post some images of what the prints look like after I do.
Deal? or you could just give us something to go on, like images.
Let me know what way you decide to go, 😉
Swiss_Cheese
The Filament Whisperer
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
@swiss_cheese
But that'd take all the guesswork out of it, and helping others would no longer be fun and exhilarating!
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
Yep it's a fair ask. It's been hard to photograph a good A/B comparison I'll see if I can attach some photos here showing the extreme cases.
I had thought about the bent heatbreak also though I've already swapped it 3 times so I don't think it's that. Starting to wonder if it's the heatsink as I haven't swapped that, but that would seem weird for why it would have any affect on the "shininess" of the top?
Also sorry for the delays in reply! I subscribed to the topic but I'm not getting e-mails when it's been replied to :/ so didn't know anyone actually replied. My apologies!
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
Here's a side by side, although it's hard to see. In person the difference is much more extreme than I was able to pick up - shinier one is on the left. Same gcode.
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
Shininess could be temperature difference.
Printer higher and/or lower temperature to get the same as the other printers.
In the past I had filament I could change with temperature, from mat to shiny.
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
@m00dawg
Are all three running the same firmware version ?
The Filament Whisperer
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
BTW I understand about the, "not getting e-mails when it's been replied to" I sometimes get them but more often then not I don't. So in order to help folks here, I have to keep going back to my profile and look at the activity column and click on each recent post to see if anyone is trying to respond, other times I will get 15 reply's to posts that I just read.
Sometimes it feels like your pulling teeth to help here, the folks who do a lot of the helping around here remain diligent, so it works.
The Filament Whisperer
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
If it is simply the shine that is of concern, you are chasing rainbows.
Surface quality can be affected by so many things.
1) Surface burnish of the nozzle. It may have a burr and polishing the nozzle might help.
2) Are all three extruders true and perpendicular to the print bed?
3) Are all the cooling fan shrouds the same? Are they also mounted identically and angled exactly the same?
4) Are all three heater thermistor profiles identical (since they are not the same part, the answer is no). Calibrating each extruder thermistor and running the PID cal after setting the proper temp coefficients would be required to normalize all three - easier to buy a batch of thermistors and hand select three that are the closest of the batch.
5) Are all the stepper motors running the exact same drive current? Do the motors all match in step linearity? Going to higher quality steppers, or even to 0.9 degree motors instead of 1.8 degree steps can help surface quality.
The list goes on ...
RE: One of my printers seems to consistently have worse top layers and I can't figure out why
Quick updates, yes same firmware. Same temperature (purposefully using the same gcode across all three to look at the differences). Then to run through Tim's list:
1. Polishing is something to consider and I might start doing this with new nozzles. I've run through multiple nozzles at this point (been chasing this down for over a year now) and I don't think it's exclusively a nozzle thing because the printer I have issues with always prints less shiny and this has been through at least 3 nozzles (but I think 4).
2. As best as I'm able to tell. Calibration shows everything is square and they look perpendicular by eye. As noted earlier in the thread, I've used multiple heat breaks and didn't see a change.
3. Yes
4. Right they're different though they did start the same. I've swapped parts around to try and see if I can spot differences and, so far, I don't see any noticeable difference. In all cases I do PID calibrations everytime I swap parts.
5. That's a good question. I didn't know that is something configurable from Prusa (the stepper motor current). They're all using the same profile in Prusa Slicer so the answer here is yes, though of note all the steppers are the Prusa stock motors.