RE: MK4 PLA Stringing
mam to stejne
RE: MK4 PLA Stringing
I am using standard mk4 settings for minis. Which doesn’t seem to have a default input shaper profile. I don’t believe it’s necessary either. I could be wrong. Until I see someone else post results and settings to match what I get now I won’t bother either.
The temps are due to the Nozzle X. But the retraction difference between 2 different pla brands I thought was the bigger thing. Only shared the basics in case someone has a similar setup.
RE: MK4 PLA Stringing
I too am having lots of stinging problems with my new MK4. I am starting to wonder if the hotend thermistor is working properly? I came from a Dragon hotend with a Nozzle X on my MK3S and never had any stringing like this at any temps. I print from a filament dryer and that should not be the problem. My temp tower did not show much difference at any temperatures.
RE: MK4 PLA Stringing
The same here - a lot of stringing, no matter what are the settings. On MK3s the same thing prints fine.
RE:
I was actually wondering - are we sure, that themperatures displayed on the LCD are actually correct? Is it working as it should? I just measured a bed on the mk3s during the print. Bed is set to 60 degrees and I have ~56 on the body thermometer, which can also measure surface. After I will finish my print at MK4, I will also set it to 60 and compare results. If it will be around 56, then it's fine. I will update the answer once I will make a test.
BTW - currently I'm printing with PETG and stringing is also there. Temp is set to 220, which is minimum recommended by filament manufacturer. If I will go higher, it will be even worse.
RE: MK4 PLA Stringing
I checked the bed on the mk4 and it's between 47 on the left corner (the one near LCD) and in average 51-52 on central area. It looks like it's a little bit colder, however I understand it's not a solid method of measure things. It's also not directly related with stringing, as the printing body can be at a specific height, so bed temp is not relevant.
I just simply thinking about temperatures of the nozzle and other components - do we see correct, real values or maybe something is causing interference. I saw that printing at 195 degrees looks much better. Can someone check using professional camera - is it 195 for real? Maybe someone has FLIR thermal camera or similar professional equipement? Maybe in fact it's not 195 but 220 and setting printer to 220 is 260? Just blind guess.
RE:
Does anybody have a possibility to measure the nozzle temperature if it is ok according to the shown numbers?
Probably I missed which FW version do you use?
RE:
Does anybody have a possibility to measure the nozzle temperature if it is ok according to the shown numbers?
Probably I missed which FW version do you use?
At my work we have a very expensive thermal camera. I will ask if I can borrow it for a day. I’ll keep you informed.
RE: MK4 PLA Stringing
I'm using the latest alpha.
RE:
So here are the results.
Measured with a calibrated IR thermometer...
I wasn't able to measure the nozzle because it's to small for this kind of equipment.
Maybe i know someone who can do this.
RE: MK4 PLA Stringing
In all logic, as the thermistor measures the temperature underneath the bed, there’s a differential between this value and the real temperature on the printing surface. The bed is basically made of glass fiber ( low heat conductivity ) and in top of the bed there’s the steel plate with PEI layers on both sides, which isolate the heat a bit more.
I also use a IR thermometer (albeit non calibrated ) and it reads 55-57C on the centre of the smooth plate if the thermistor setting is 60C. Temperatures around the edges of the plate are always lower, although printing inside an enclosure helps to reduce these differences.
The values that you get (52C on the centre and 48-50C on the corners ) seem a bit extreme. Perhaps the thermistor doesn’t makes a perfect contact with the bed ?. Sometimes, the kapton tape fixing the thermistor assembly sags a bit after a period of time
RE: MK4 PLA Stringing
In all logic, as the thermistor measures the temperature underneath the bed, there’s a differential between this value and the real temperature on the printing surface. The bed is basically made of glass fiber ( low heat conductivity ) and in top of the bed there’s the steel plate with PEI layers on both sides, which isolate the heat a bit more.
I also use a IR thermometer (albeit non calibrated ) and it reads 55-57C on the centre of the smooth plate if the thermistor setting is 60C. Temperatures around the edges of the plate are always lower, although printing inside an enclosure helps to reduce these differences.
The values that you get (52C on the centre and 48-50C on the corners ) seem a bit extreme. Perhaps the thermistor doesn’t makes a perfect contact with the bed ?. Sometimes, the kapton tape fixing the thermistor assembly sags a bit after a period of time
I have the same values as Lode, 52 and 48 on corners while the same measure method on mk3s shows 55. However, it's not exactly the reason for stringing...
RE: MK4 PLA Stringing
Well, it’s not a big deal if you know that the values are not correct but how do we have to deal with it ? Let’s say i’m printing Prusament PLA. Nozzle 215 Heatbed 50-60. Do I have to use these values or should i increase the temperature ? Is there any information from Prusa about this ? Maybe it’s a little bit trial and error altough my first prints when I first used my printer were just perfect but now the corners from every larger object I print don’t stick to the bed.
RE: MK4 PLA Stringing
That's a good question, maybe someone from Prusa team will take a look at the topic...
RE: MK4 PLA Stringing
the guys and gals at prusa rarely visit here it's more of a Pier to Pier support group.
the temperature sensors are thermistors which are not fantastically accurate. the prusa default temperatures are usually OK!
but you are wise to do some test prints. temperature towers are available for different filaments. (Make sure that you get a ready sliced version to ensure that the temperature changes have been integrated into the Gcode.
the extruder temperatures have more chance of being inaccurate than the heatbed, typically, because the extruder temperature is much higher than the thermistor test temperature.
People often find that the build plate adhesion reduces over the first few prints, this is often because you get fingerprints on the surface which reduce adhesion.
I take my build plates to the sink, and wash them with hot water and a little dish soap, then rinse and dry immediately, using clean plain paper towels. 
Happy printing, 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: MK4 PLA Stringing
Same issue here.
The same file printing at the same time with the same filament poduces stringing with the mk4 and a perfect result with the mk3s+.
Intrested if someone could figure out something with prusa…
RE: MK4 PLA Stringing
Souhlasim stejne U petg sem vyresil teplotou filamentu 220 stupnu. Ale hruza.....PLA neresitelne.....
RE: MK4 PLA Stringing
Same here. Also a bizarre amount of fine stringing. Also replaced nozzle+heater+thermistor, without any improvement. Same filament on mk3+ and on Bambu X1C is perfect. Hope Prusa is aware of this because it's a huge disappointment...
RE: MK4 PLA Stringing
I raised PLA temp to 245 and that reduced stringing, go figure
RE: MK4 PLA Stringing
So, anyone was able to fix the stringing issue? I'm having the same problems.