Nozzle temp reporting 215c but appears to be 127.5c.
Nozzle temp reporting 215c but appears to be 127.5c.
I have happily printed over 4 km of filament on my MK3s with only a small handful of easily resolved issues.
Recently I starting having significant under extrusion issues. I tried several easy steps without success. Acupuncture needle to clean the nozzle. Multiple cold-pulls without seeing signs of any burnt material. Replaced the .4mm nozzle new Prusa .4mm nozzle. Upgraded firmware. Made sure Slicer was also set to .4. Swapped out filament. Checked the Bondtech gear alignment. Still getting serious under extrusion.
Suspected the reported temp of the nozzle (215c for PLA) and the actual temp weren't the same.
Using infrared thermometer, when the printer had been off for an hour, the ambient room temp, the bed temp and the nozzle temp were all at or close to a warm Floridian 28c. The thermometer and the display on the printer agreed.
Then I preheated for PLA (215 nozzle, 60 bed).
The thermometer and the printer agreed the bed was about 60c.
The printer reports the nozzle is 215. But the thermometer reports 127.5c. I tried aiming the thermometer at several different spots on and around the nozzle and the heat block. But 127.5 was the highest reading I could get.
Prusa MK3S
Kit
Support:
Firmware: 3.8.1-2869
1_75mm_MK3
EINSy_10a
E3dv6full
Date: Oct 24 2019
Voltage
PWR: 23.8V
BED 23.7V
Statistics:
Total filament 4168.99m
Total print time 178d :17h :04m
Temps measured with Etekcity Lasergrip 1022D Infrared Thermometer.
Room temp: 28.4c
Printer fully cooled:
Bed per thermometer: 27.9c
Bed per MK3s: 28
Hotend per thermometer: 26.9
Hotend per MK3S 28
Printer preheated for PLA target 215 nozzle, 60 bed:
Bed per thermometer:
53.0 with metal plate
57.0 without metal plate
Bed per MK3s: 60
Hotend per thermometer: 127.5
Hotend per MK3S: 215
RE: Nozzle temp reporting 215c but appears to be 127.5c.
An infrared thermometer has difficulty measuring the temperature of shiny metal surfaces due to its reflection. If you paint the surface black (eg black tush pen) the result will be more accurate.
Bear MK3 with Bondtech extruder
RE: Nozzle temp reporting 215c but appears to be 127.5c.
@rhdreambox
I have found my thermometer to be quite reliable on a variety of matte, glossy and even mirrored finishes.
But not wanting to leave this stone unturned, I used a black sharpie on one side of the heat block and the nozzle. After preheating to 215/60, my results were almost identical.
The printer thinks the nozzle is about 215c when in reality it is closer to 125c.
Assuming for the moment that these temperature readings are correct, or even off vaguely close to being correct, what could cause this discrepancy?
RE: Nozzle temp reporting 215c but appears to be 127.5c.
It’s possible you have a bad thermistor or a thermistor wire that is partially broken. If the Einsy sees a thermistor resistance that normally corresponds to a temperature of 215 degrees it will maintain the temperature at whatever is giving that thermistor reading. In your case a temperature of 127 degrees seems to [incorrectly] provide that thermistor resistance. It might also be possible you have bad thermal contact between the thermistor and the heat block.
DJ
RE: Nozzle temp reporting 215c but appears to be 127.5c.
Hi,
Hey, richard.d.boniface, did you figure it out?
I just upgraded my MK3S to the Bondtech LXG "Shortcut" Mosquito -- I am having the exact same problem. First Layer calibration seems to OK at Live Z = -0.920mm.
PLA temps set to 215/60 -- I print the the Prusa Logo and other test prints and all I get is a pile of spaghetti. First layer doesn't adhere at all. I verified that the bed temp is 60C with a FLiR camera, but the extruder only reaches about 145c to 160c, yet the info screen shows it's at 215C. I turned up the nozzle temp to 295C, the physical measurement was about 200C -- the filament started to seem to work better. I tried using a cheap Chinese IR+Laser temperature reader, and it reported around 160C as well.
Perhaps the thermistor was damaged? It did not have thermal pasted on it from the factory before the conversion. But the BondTech instruction indicated to use the supplied Silver paste. In BondTech instillation video I noticed the polarity of the stock Prusa thermistor was reversed from how my unit came. I plugged it back in the way it came out... I assume polarity doesn't matter on a thermistor (whereas it does matter on a thermocouple).
I just received a new Slice Engineering heat cartridge (300C) and thermistor via MatterHackers. So I will try those I guess.
Suggestions?
Scott
RE: Nozzle temp reporting 215c but appears to be 127.5c.
Hey, Richard, did you figure it out? I am having the same problem after upgrading to BondTech using the stock heat cartridge and thermistor. See my posting for more detail.
Thanks
Scott
RE: Nozzle temp reporting 215c but appears to be 127.5c.
Did changing out your thermistor fix the issue? I have just run into the same thing on my Mk3S. Nozzle temp reports 215 but laser thermometer says 130. I printed earlier today, after having some print issues over the last couple of month which I thought were solved. I'm now thinking the thermistor may have been my problem all along.
AllArmsLLC
RE:
Neither the OP (Richard) nor Scott have made any posts to this forum besides the two each in this thread, so I kind of doubt if either of them are paying any attention.
RE: Nozzle temp reporting 215c but appears to be 127.5c.
Sorry for missing the previous posts.
Yes. I think.
That is to say I replaced the thermister and the rest of the hotend assembly.
I wish I had tried just the thermister. Assuming it worked it would have saved me about $70 USD. But I had been trying so long to fix it that I was frustrated and decided to replace the entire hotend assembly just to have a better chance of being done.
Since that time I have moved. Since moving, I have had a lot of print failures due, I suspect, to my Z-axis being out of alignment. Tried assorting troubleshooting including the full self test wizard. I'm sure, with time, I could have solved the issue. But I was again quite frustrated by the number of times I tried to fix the issue but kept failing. I'd get a few prints to work and then I'd have bed adhesion issues or something else.
Even before the above problems, I had frequent first layer issues. Dialing in the Z-offset seems more art than science. And I just wasn't good at getting a reliable Z-offset. I was envious of newer printers that had true automatic bed leveling by using pressure sensors within the printhead.
So, I gave up on the Prusa MK3S. I purchased an AnyCubic Vyper and have been very happy with the fully automatic bed leveling.
RE: Nozzle temp reporting 215c but appears to be 127.5c.
You can test the heater and thermistor using a multimeter: https://help.prusa3d.com/article/multimeter-usage_2117
I would think your temperature reading is not correct since I doubt you can extrude any PLA though a 130°C nozzle...
If at first you don't succeed, skydiving is not for you.
RE: Nozzle temp reporting 215c but appears to be 127.5c.
Yes, I'm getting ready to do that now, also what I suspect. It's just odd that it printed for 3+ hours yesterday morning, and then failed on filament load later in the day.
Posted by: @robin
You can test the heater and thermistor using a multimeter: https://help.prusa3d.com/article/multimeter-usage_2117
I would think your temperature reading is not correct since I doubt you can extrude any PLA though a 130°C nozzle...
AllArmsLLC
RE: Nozzle temp reporting 215c but appears to be 127.5c.
Well, I tested the thermistors and they are both right in the range.
AllArmsLLC