Accuracy of the extruder temp sensor
Hello, a couple of questions regarding the temp sensor in the heater block.
I always find myself having to add 5-10 degrees to default temperatures in prusa slicer, for example when printing pla (prusament petg profile is already about 10 deg higher than generic petg)
So that made me wonder how accurate the temp sensor is vs what i have set the temp to, perhaps something is not quite right and real temp is lower than expected and forcing me to increase it a bit.
So what i did was to set extruder to 220, wait for temp to stabilize then used the temp sensor on my multimeter (k-type temp sensor that came with it)
If i hold the temp sensor to nozzle it shows 190 degrees, if i poke the temp sensor between nozzle and silicone sock so it touches the heater block, i end up with 200 degrees.
Still around 20 degrees too low compared to the 220 i set.
I expected the temp to be a bit lower due to measuring from the outside and perhaps the multimeters temp measurement isn't super accurate but i did not expect a difference of 20 degrees.
Also considering i have the following changes: titanium heatbreak, nickel plated coper heater block from e3d and a plated copper nozzle.
I wonder why it is so big difference and if there is something i can do about it.
I do have a spare prusa specific termistor in my box of spare parts i bought from e3d a while back, haven't used it yet.
Ideas?
RE: Accuracy of the extruder temp sensor
If you are new to 3D printing, I would recommend you get good at the stock printer before modifying it with any changes in the heartbreak, thermistor, or hotend. Every change you make can create a new variable toward failure. If you are getting erratic results from the thermistor, replace it alone and see what happens.
--------------------
Chuck H
3D Printer Review Blog
RE: Accuracy of the extruder temp sensor
@cwbullet
I'm not new to 3d printing, i've had the printer for around 2 1/2 year (+mmu2s)
(was forced to reset prusa account some time ago since they can't handle email changes, this forced a reset of forum account too)
What i tried to describe above i would not call a failure, it is easily worked around by just doing what i have always done, add 5 or 10 degrees and it works just fine.
But i would like to know why that is needed especially when using a material that conduct heat better plus isolating the heaterblock with a silicon sock.
With those additions it should have made the filament melt better and quicker since heat can be easier transferred to nozzle and filament.
Also a 20 degree difference is quite significant.
RE: Accuracy of the extruder temp sensor
@tobbe
That is significant. I have used silicone socks. I did not measure the heat difference but I would think it would not make a difference. The thermistor should still measure the same. Did you recalibrate your PID?
--------------------
Chuck H
3D Printer Review Blog