RE: MK4 PLA Stringing
It seems like it's the hotend thermistor. I kept getting little dots on the bed where it was probing, but the probe temperature is 170°: PLA shouldn't melt at 170.
I created a small temperature tower model, to do some quick tests without using a lot of filament, and confirmed that I can print PLA with the hotend temperature set to 170°. I'm printing Creality PLA which seemed normal on the Ender 3. On my Mk4, the sweet spot for PLA seems to be around 175°.
If you'd like to try your own test, I uploaded gcode files on Printables. Here's how to run your own test:
- Go to Small Parametric Temperature Tower and download the "thermistor test" gcode.
- Send it to your Mk4 with the input shaping firmware.
- Watch it print, and cancel the print when the extruder stops pushing out plastic.
- The topmost completed segment is the lowest temperature you can print. It should be 180 or 190, I think.
It would be nice if the firmware had a way to calibrate the sensor: a temperature adjustment offset seems like it could help here. At this point, though, I can work around whatever the issue is by setting my filament temperature to 175.
RE: MK4 PLA Stringing
Few minutes of chat.
How long did it take until they said that they are going to send a new one? Waiting a week now for a reply:/
RE: MK4 PLA Stringing
Because I wanted a second full hotend for easy switching I ordered a full set. It arrived yesterday, it was also black. I will test it later today to see if it is working. Keep u posted.
RE: MK4 PLA Stringing
One more with the stringing problem. Tried everything and also with support.
Trying to print a Prusacaster and the hexagon parts are a mess. I am using Filament PM.
The support agent told almost immediately to lower the temperature 15º from the 215 i told him, so they know something is not right.
I'm going to do another test and charge again on support.
I think everyone needs to do this (if they have the problem) so a fix is pushed.
RE: MK4 PLA Stringing
Yeah lowering temp by 20 helps me a lot. Tested with pla and petg. I suggest everyone to try it. It is still not perfect but it helps a lot. Ať least i can print untill fix is aviable.
RE: MK4 PLA Stringing
Lowered it by 30. I print now witb 180 and nearly no stringing and so far no more layer shifts
RE: MK4 PLA Stringing
My result printing prusament galaxy black at 170 on the new thermistor (black)
RE: MK4 PLA Stringing
So a new thermistor is not the solution?:(
RE: MK4 PLA Stringing
Printed at 195 from 215 and it's almost perfect. It's a Prusacaster piece in Red Pearl PLA (Filament PM).
The quality is perfect and the stringing practically gone.
RE: MK4 PLA Stringing
Did you change anything else?
RE: MK4 PLA Stringing
No, just the temperature.
RE: MK4 PLA Stringing
New firmware didn‘t helped for me.
But had another chat with PS and they sent me as well a new thermistor.
should arrive on friday and will test it afterwards and let you know.
RE: MK4 PLA Stringing
I'm starting to think the printer is fine, and I just haven't dialed in my filament yet.
RE: MK4 PLA Stringing
Anyone actually solved the temperature problem?
I was offered the XL thermistor until they find a final problem, but I have doubts that this will solve the problem.
RE: MK4 PLA Stringing
No change here with any firmware or PrusaSlicer version. I think most people here are just using a temp in the 190 range and are living with it until a real fix arrives. Mine definitely seems like it is hot. When I tried to run PETG out of it the filament was still oozing out the nozzle when it cooled down for the bed level. Leveling even failed a couple of times before it went. I came from an MK3+ with a Dragon Hotend and when I did a temp tower with that it would look great from 200 to 215, so this is a bit off to say the least.
Anyone actually solved the temperature problem?
I was offered the XL thermistor until they find a final problem, but I have doubts that this will solve the problem.
RE: MK4 PLA Stringing
New thermistor from support came in today. I have spool of prusament galaxy black pla so i will do some testing now with default profiles and i will report back.
RE: MK4 PLA Stringing
Thanks! We will wait for your experience.
RE: MK4 PLA Stringing
Ok guys listen up i have some news for you!
New sensor is definetly from Prusa XL. Same markings on package, same lenght.
I have made test with old sensor and then same gcode with XL sensor. My old sensor was black cable one.
With old (black one) there is really bad stringing. With new (XL one) there is almost not a single string. For me this solved the issue!
I will say that with new one printer is heating up little bit faster. But this is my feeling as i have not measured heating time.
I will pull photos fom mobile and post them here in a minute but i was too exited about this to not to share with you guys.
RE: MK4 PLA Stringing
OK here are the photos.
You can see two thermistors are different. Longer one from XL worked for me.
On the stringing test. Right one is printed with XL thermistor.
RE: MK4 PLA Stringing
They are sending me a new thermistor. Don’t know which one. Hopefully it will solve my problems too