Thermistor temperature fluctuations
Hi All 😊聽
My Prusa Mini's have been running for hundreds of hours, but now i'm getting issues on all of them. Fan's get broken, thermistors stops working and after a replacement under warranty (thumbs up prusa support 👍 ) it's all working again so that's great. But now the strange thing i've noticed that print profiles i've been using several years now, are not consistent anymore. And I didn't understand it, it took me a really lot of time, but now I think i'm getting close, at least for a part of it.
On the printers where i've changed the thermistor I got a lot of stringing en blobs. And after a lot of cleaning and changing PFTE tubes, etc etc. I found out that it was as simple as turning down time hotend temperature by 10 degrees. To be sure it was the new thermistor i've moved it to a printer without this issue and indeed after replacement it also suffered the same issue. Reconnecting the old thermistor solved the problem.
Now I know this i can tune the temperature on the specific printers, but is there a way to setup the printer that it always retracts 10 degrees of the GCODE temperature?
聽
RE: Thermistor temperature fluctuations
The temperature shown on display is not the same as the real temperature. I therefore always need to add +5deg to the nozzle聽 and bed values. Is there an option to "fine tune" the temperature in mimi+ firmware ?
RE: Thermistor temperature fluctuations
No unfurtunatly not, at the moment I enter them in Octoprint as an temperature offset but this has to be re-entered every time it powered off.聽 It works but it would be better to program it somewhere in the EEPROM so it doesn't depends on external software.
RE: Thermistor temperature fluctuations
Sid, did you do a replacement by original prusa mini thermistor?
even an old man can learn new things 馃檪
Standard I3 mk3s, MMU2S, Prusa Enclosure, Fusion 360, PrusaSlicer, Windows 10
PRUSA MINI+ Prusalink + Prusa Connect
RE: Thermistor temperature fluctuations
One possible work around can be to create a copy of the filament profile in prusaslicer and change the temperaturs
even an old man can learn new things 馃檪
Standard I3 mk3s, MMU2S, Prusa Enclosure, Fusion 360, PrusaSlicer, Windows 10
PRUSA MINI+ Prusalink + Prusa Connect
RE: Thermistor temperature fluctuations
Yes it are original prusa replacements. Yesterday i've measured multiple thermistors, two new ones and 2聽 older ones
Unsued new 1 -> 131 k惟聽
Unsued new 2 -> 126 k惟聽
Old 1 -> 130 k惟聽
Old 2 -> 138 k惟聽
All measured next to eachother at room temperature. I don't know if this 'small' differences could be a cause of the different temperatures. Maybe they also have a different curve when heating up or cooling down.
It would be great to get more tuning at printer level. If you use one printer editing the gcode isn't a big problem, but when using multiple printers it's difficult to keep track of and a lot of work. (I sync all gcode accross my printers)
聽
RE:
I am using origin谩l prusa with no mods. Even a钮 the moment there are different temperature shifts on bed and head, looks the only real solution could be a fw temp_shift parameter(s). I'll try to write the suggestion/request into github. Thanks you.聽