Prusa MK4 - not for my printer farm!
I have a small printer farm with 20 Prusa MK3S+ and wanted to buy 20 more printers. That's why I ordered an MK4 for testing. The printer makes a good impression and if you print PLA with a 0.4 nozzle, everything is fine. Above all, very fast and clean. The quality of the 1st layer is breathtaking. The only problem is that the accuracy of fit of some printed parts is different to printing with the MK3S+, even if you print with exactly the same profile.
But... I mainly print spare parts from PETG with a 0.6 nozzle. That's terrible with this printer. Not only is it impossible to get a reasonable bed adhesion at the corners of the print bed (I have tried everything from different print beds, all possible profiles to very slow printing), the print bed is already completely contaminated with filament before printing due to the leveling process. Even if it doesn't significantly affect the print result, you have to scrape the dirt completely off the bed again after each print (not so easy with PETG). This costs a lot of time and makes no sense.
In addition, when using print server software (such as a repetier server), which is normal for printer farms, you can neither see the print progress on the display or the remaining time and you cannot even interrupt the print directly on the printer. Not usable for me like this. Prusa writes that they tested the printer for hundreds of hours in their print farm, but unfortunately they didn't notice.
So, if I needed ONE printer on which I wanted to produce a few parts in the middle of a print bed from time to time, I would probably buy the MK4 again. It's not a bad printer. And really fast with input shaper. But unfortunately, in my opinion, it is not (yet) suitable for economical use in a printer farm. And, by the way, I doubt that Prusa itself uses the printer on a large scale on its own farm!
So I have to buy another 20 "good old" MK3S+, which I think is a shame.
RE: Prusa MK4 - not for my printer farm!
I havent tested the o.6 nozzle on my mk4 yet but i can imagine the oozing being worse with a larger size. Kinda curious what petg youre using and nozzle/bed temps? I also think the display will improve a lot in due time as they're yet to bring the touch screen function etc. Im confident they will improve it a lot tbh. The oozing is a bit of a problem for me too with my o.4 nozzle but but im kinda new to this printer, still testing and figuring things out. I notice it oozes a lot less when its just been turned on. So far im getting good adhesion on the very far sides of the bed. Whenever im getting bad stick i usually turn the heat on the nozzle up a touch, or the bed if its within recommended filament settings. I get more adhesion problems with pla on the satin bed, but i just need to test settings more i think
RE: Prusa MK4 - not for my printer farm!
try 70C on the heatbed for PLA
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
RE: Prusa MK4 - not for my printer farm!
Adhesion is not generally poor. Only on the sides and corners of the bed. This is actually normal because the temperature is lower there, but it is still good on all my MK3S+ with 80C bed temperature. With the MK4 it is worse at 90C bed temperature!
One reason could also be that printing is too fast and the individual layers do not have enough time to cool down. Especially for parts with a lot of infill, this can cause the part to warp and detach from the print bed. However, I have also printed with 50/mms (15/mms first layer). Unfortunately, the result is the same.
I have prevented oozing with my MK3S+ by using a customized start Gcode, which performs the bed levelling at 160C at the nozzle and only then heats up to the full temperature. Works wonderfully. Unfortunately, the MK4 does not have this either and I am not yet aware of any method to prevent this (although many users have the same problem).
RE: Prusa MK4 - not for my printer farm!
Have you tried the Satin sheet? I'm told this is the way to go. Or if really focusing on PETG and you haven't tried already, the traditional textured option is supposed to be good.
RE: Prusa MK4 - not for my printer farm!
After reading this tread is hard to not say sth. about MK4 vs MK3.
Most of your observations are very correct. I have been working on Prusa MK3S last three mounts and now I have also MK4. This new features which are the benefit of MK4 are also in same time issues creators.
On MK3 I was using only smooth PEI sheet and everything print was perfect from PLA, PETG to ASA and Easy ABS from Fiberlogy (no chamber). Printing same models on MK4 start to be first disaster and challenge how to tune them to properly print out on this "new MK4 toy"
Input shaper and speed
This is the biggest game changer on MK4. From one side speed is sth. what everybody likes. Get our prints, models faster its nice. From other printer has half of that time to print properly the material and to stick it to surface. Mostly this factor creates a lot of issues on MK4
New bed leveling (no PINDA)
PINDA on MK3 was good but using tensonometer give change to just replace bed sheets from PEI to satin and textured without any re-calibration.This is great and also worst thing on MK4. If you are used to use smooth PEI for every material on MK3 and you will start to do same on MK4 you will start to strangling with this filaments dots contamination made during calibration proces. Removing them (if you use PETG) is a nightmare.
WiFi, Ethernet
Another great add-on on MK4 you do not need to take your SD card, copy gcode and back to your printer. But my feeling is that if you try to do too much over network with printer have affect in shifted layers. Not always but it happens or it just my expirence ?
Remedy:
Forget how you use your MK3 and completely change approach for MK4.
- smooth PEI as a one universal sheet will not work here.
I personally recommend like below:
Smooth PEI -> PLA only,
Satin -> PLA, PETG, ASA, ABS,
Textured -> PETG, ASA, ABS
Most universal one and game changer is Satin. Cleared (by 99,9% IPA) is best first choice for every one material.
- speed...try to slow down speed of first layer in slicer to speed of MK3. I personally set this parameter to 28. Best option will be if slicer give a chance to set lower speed to first third layer not first only until cooling fun will switch on but I do not see such option. You can also slow down printer to 70% from printer menu and wait until it will start 3rd layer. Of course this is not a solution for farm.
- modifies start gcode in slicer to make nozzle cleaning and bed leveling in 170deg of C instead of 195 for PETG
M140 S[first_layer_bed_temperature] ; set bed temp
M104 T0 S{((filament_type[0] == "PC" or filament_type[0] == "PA") ? (first_layer_temperature[0] - 25) : (filament_type[0] == "FLEX" ? 210 : (filament_type[0]=~/.*PET.*/ ? 170 : 170)))} ; set extruder temp for bed leveling
M109 T0 R{((filament_type[0] == "PC" or filament_type[0] == "PA") ? (first_layer_temperature[0] - 25) : (filament_type[0] == "FLEX" ? 210 : (filament_type[0]=~/.*PET.*/ ? 170 : 170)))} ; wait for temp
Bed heating: I have feeling that as Josef mention on one of the Prusa movies on YT they have 3 different heated bed suppliers and in my opinion they are not equal. Heat bed on MK3 heat much better than on MK4.Right now before printing I'm setting bed temperature manually and wait 5 minutes before printing. This helps. Maybe this is consequence that on one of last FW update on MK3 they separate bed heating from filament change nozzle heating. Previously changing filament nozzle and bed was heated together and this give this additional 2-4 minutes for temperature stabilization.
RE: Prusa MK4 - not for my printer farm!
Another great add-on on MK4 you do not need to take your SD card, copy gcode and back to your printer
ok for all other point and the T° at 170C sure, 1 point i can't understand is if you have perfect 1st layer on the sheet why you have fit issue ? inever print petg on smooth only satin which i use all day for all, i don't clean it anymore almost...ok not good but still printing perfectly mk3 or mk4 even ASA
@robgold ,right but if you add the simple rpiow2 (20$) on your good old rambo you'll fly away !! and see how fast is to send the files from slicer to prusalink...
RE: Prusa MK4 - not for my printer farm!
Boy, sounds like I really should bite bullet and get satin. Sounds like they really should ship with this.
I've finally found a routine cleaning regimen that seems to work well for my smooth sheet as I was having lots of first layer issues. I dump a Large volume of IPA on sheet and circular scrub this with a paper towel and then dump a small volume on and linear wipe with a microfiber cloth. Other variations of routine cleaning have not worked for me and failing to clean between prints is almost always a no go.
RE:
Boy, sounds like I really should bite bullet and get satin. Sounds like they really should ship with this.
I've finally found a routine cleaning regimen that seems to work well for my smooth sheet as I was having lots of first layer issues. I dump a Large volume of IPA on sheet and circular scrub this with a paper towel and then dump a small volume on and linear wipe with a microfiber cloth. Other variations of routine cleaning have not worked for me and failing to clean between prints is almost always a no go.
"Prusa should....".... Oh my....
IPA is no cleaning agent and as such will not clean the sheets. Virtually all first layer adhesion problems which have been reported here, even back when there was only the smooth sheet available, seem to go back to wiping the sheets with IPA only without cleaning the sheet first vigurously with hot water and a non re-greasing detergent. IPA can be used thereafter or between prints for several times, but cleaning the sheet after some prints is not replaceable even by a gallon of IPA.
Just my 2 cents.
I try to give answers to the best of my ability, but I am not a 3D printing pro by any means, and anything you do you do at your own risk. BTW: I have no food for…
RE: Prusa MK4 - not for my printer farm!
I just assembled my MK4 over the weekend (love it btw!), and have printed many prints using PETG and a 0.6mm nozzle. No adhesion issues at all for me with the satin or textured PEI sheet so far. I typically wipe down the satin sheet with IPA each time before printing, but will try wiping it down every other print or so now as adhesion seems to be so good.
RE: Prusa MK4 - not for my printer farm!
Yeah, everyone has an opinion on this. I understand. I've tried pretty much all of them. I still wash occasionally too, but this is what works. I print frequently. I'm not sure why peoples experiences are so different with these sheets, but I'm now an internet armchair expert on this and feel comfortable saying that there just doesn't seem to be one right way.
RE: Prusa MK4 - not for my printer farm!
Yep understood as there seem to definitely be folks on both side here. I actually did run into adhesion issues with the textured PEI sheet on my MK3S+, and even after washing with soap and water still had some issues. What ended up working for me was to use Magigoo on the sheet for awhile and then washing it down with soap and water again. Not sure why that helped, but my guess is it must have gotten some of the embedded (factory?) oil or grease off the surface better.
RE:
yes.. this has been covered in other threads over past year.. the rough (textured) sheet has a bit of film on it from the manufacturing process.. Takes a few scrubs.. even some very mild scrubbing with the back of a plastic kitchen sponge to get rid of it.. Mine was quite bad initially until I read this forum (and I had cleaned lightly with soap/water.. but I found I had to do more scrubbing. Once you do, the adhesion is much better. In many prints with both PLA and PETG, I have found dish soap and hot water works significantly better than 99% IPA. I still use IPA if I've touched the board and want to get rid of some hand oils.. but soap will dissolve stuff IPA won't.
RE: Prusa MK4 - not for my printer farm!
I now suspect that my adhesion problems must have something to do with the bed temperature. This means that the bed does not really reach the set temperature. Tomorrow I will get a suitable thermometer to measure it.
It can't really be anything else. I have tested all types of (properly cleaned) sheets with different temperatures (up to 80C with PLA!) and different Z heights.
The result is horrible even with PLA. Here is a comparison with the MK3S+ and the MK4. Same print part, same sheet, same filament and same settings.
MK4
MK3S+
BTW:
does anyone know how I can set Prusasclicer 2.6.1 so that the Z-seam is on the back?
The selection is still available in the printer settings, but it has no effect for me. The seam is still set randomly.It worked perfectly with Prusaslicer 2.3.
Thanks!
RE: Prusa MK4 - not for my printer farm!
Look up "seam painting".. you can paint the seam to be where you want by selecting the model, then on left side, it is second icon from bottom.. or search Prusa knowledge base..
RE: Prusa MK4 - not for my printer farm!
yes, but unfortunately I cannot duplicate the setting. This means that if I print 10 pieces, I have to paint the seam on every single piece. Not practical.
RE:
Yes, you can.. put on one object.. paint the seam.. duplicate the object and the seam position gets duplicated.. You can also use the search tool to look for stuff.. go to expert mode and print-settings then hit the mag. glass and type 'seam'.. You have various seam options.. looks like one can put seam on rear.. Click on each below to see more of the screen shot.
RE: Prusa MK4 - not for my printer farm!
Sorry but I know where the settings are. They just have no effect.
Just select "Rear", print something and you will see that the Z-seam is still random or nearest and not at the rear.
On the Prusaslicer 2.3 it was perfectly rear. Very useful, for example, to hide the z-seam on objects on the underside.
Unfortunately, the prints (especially with curves) now look worse than before.
RE: Prusa MK4 - not for my printer farm!
it's strange about the seam !! if you zoom a lot you can see it before printing !! try all option or paint too in the 2.6 slicer !! and on different object !! why not