So, a week ago I started having problems when printing with TPU. After and hour of so of printing, "temp runout" error showed up on the screen. After that I checked for the all hotend (e3d V6) connections, like thermistor, tightening heatsink to the nozzle and all that. Nothing was loose. The problem was still there.
After some more research I tried replacing the thermistor (original that came with CR10s). Now the error that came up was MINTEMP. It didn't even read the room temp. Heatbed works fine.
I checked the board, nothing looks loose or damaged.
Do you have any ideas what this might be? Thanks in advance for your input!!
Hi, I tested mine a while back on my cr10s pro and it measured 82.2KOhm @ 31°C. IIRC the resistance goes lower as the temp goes up on them.
That's the best way to check if the problem is the thermistor or not. I have been fortunate to not have them break on my printer and would just replace them if they did. If you do re-solder it as was suggested, make sure you check the temp on the shrinkwrap being used since the stuff I have seen on them appears to be either ptfe or something close. I'm sure my normal shrinkwrap would probably melt in contact with the block.
Hi thing! Ok I'll get a multimeter and check that. I changed the whole thermistor, from the E3D to the stock that came with the printer. I soldered the wires much higher where the heat is not a problem.
The thermisters are absolute rubbish, even replacements. I broke an entire pack trying to install a new one while being exceptionally careful. The fix is to cut off the shrink wrap where the sensor leads connect to the the wires. Pop the wires off, trim off the solder, strip back the wire and wrap it around the lead a few times before resoldering. Remember to put some heat shrink on before you solder. This is super reliable and will probably fix your original too.
You can test the thermister for continuity but the way they crack it can be intermittent
So if I understood that, you are telling me to cut the wires that go into the sensor, strip it, wrap it and resolder? Where would the heat shrink go before soldering? Covering the sensor so the heat doesn't creep up? Sorry for the many questions, I'm kind of new hehe.
Thanks for your reply!!
I'm recommending you cut the existing black heat shrink off the 2 wires, detach the leads, then cut the wires. After you cut the wires, split the two strands so you can slide two lengths if heat shrink that are long enough to cover the new joint. Strip back the wires, twist it around the leads, solder, slide the heat shrink over and shrink. The new heat shrink is to electricaly insulate the solder joints. Do not cover the sensor, it will likely cause a lag in your readings. The sensor is the glass bead. Heat creap is a cooling issue, not a sensor issue, your controller will shut everything down before it gets hot enough to damage that sensor. Unless you really tweak the firmware but even then I'd have doubts.
So, the E3D thermistor I had, had actually no heatshrink. Just two split wires coming out of the metal (sensor?) with a blue fabric. No leads, just the wires, some damn thin wires.
Stripped part of the wires and cut them, soldered them on, heat shrink, and then the solder came out bc of the heat needed to shrink the heat shrink. So that thermistor is useless now.
Where I live they only have an Anet A8 thermistor replacement. It does not have that metal part that goes inside the heatblock.
I feel I'm screwed now :(
Sucks, So you have a cartridge type thermistor that E3D sells, they should be reliable (sorry to say).
I missed when you originally posted that it sounds like you were using the original CR10 thermistor with the E3D hot end - can you confirm that? Also confirm that you swapped the original CR10 Thermistor with the E3D genuine with the blue wires which then did not work.
If that scenario is correct then I think one problem could be that the original CR10 thermistor is a 100K NTC 3950 Thermistor (https://www.th3dstudio.com/product/3-pack-100k-thermistor-cr-10-tornado-ender-2-and-most-3d-printers/) and the original E3D thermistor appears to be a ATC Semitec 104-GT2 or similar(https://matterhackers.dozuki.com/Wiki/Firmware_Configuration_for_the_E3D_v6_HotEnd). They are both 100k but need different configurations in Marlin (the CR10 is a "type 1" thermistor and the E3D is a "type 5" thermistor in marlin).
The good news is that you can change the thermistor type in firmware if you cannot get the same one as stock (does requires working with marlin config files and compiling it, sounds more difficult that it is). You can see where thermistors are configured in marlin here (look for "thermistors" - there is a table):https://github.com/MarlinFirmware/Marlin/blob/2.0.x/Marlin/Configuration.h
When switching from the stock CR10 thermistor to the E3D thermistor you would have had to change the type in firmware since they have different characteristics. If you have never touched the stock firmware and don't want to, you can just look for a replacement CR10 thermistor (type 1) and mate that with your hot end, as it sounds like you may have had set up originally. Or if you can make the firmware changes to support the e3d thermistor, then you could use the the genuine E3D or similar since I would bet that E3D had a good reason for going with the different type. However I use the stock "type 1" thermistors on 2 of my printers and the "type 5" on my Ender3 which as an Aero and both are reliable enough.
If you want a simpler way to upgrade then you can check out TH3D's online configurator (https://ezfirmware.th3dstudio.com/) - and their videos on how to use it.
Additionally, From what I read, the Anet A8 uses a "type 5" thermistor:
I also found that appears correct by checking the example config for marlin (Configurations-release-2.0.5), and that shows in the Anet A8 configuration.h example that the thermistor for the A8 is a "type 5". That is the same as what the stock E3D thermistor uses.
It is also possible that none of this will matter and the input is broken on the board. Possibly the wires got shorted or something. There is a a way I have tested this (on my CR10S Pro and Ender3), however it requires either some resistors or a 100K Ohm (edit) audio taper potentiometer to test it. Basically I just substituted the resistor or pot with the thermistor, and watched if the display shows something reasonable for the resistance value used - ex 30°C for 80Kohms. More on that here: http://www.mystoopidstuff.com/blog/testing-a-thermistor-input-on-an-ender3-and-cr10s-pro
Woow thats a lot of useful information!! Thank you for taking your time!
On your first doubt, I was using the thermistor that came with the v6, I damaged the original from the cr10s. Yes, swaped to the blue-wired E3D thermistor. It has been working great for almost 3 years, until now. I've never even used the original cr201s hotend.
I also flashed the firmware to the TH3D one, I will check the thermistor types in there. But I remember that it was already pre-configured for E3D V6 hotend.
Luckily, I've found a place where they sell replacement parts, and they can bring me an original thermistor, the one with the blue wires. But still, after that I'll check the firmware.
And, yes, before ruining my thermistor, I opened up to check the board, and everything looked good and in place, no loose or broken wires. I haven't checked it with the resistors as you said. I'll try that too.
Thank you again for your answer! I'll report soon
No problem. If you used TH3D and have it set to use the E3D then it should auto-magically have configured the thermistor to match, so no problems there. And your plan to swap with the original makes sense since those are good thermistors. I even had mine survive cleaning a mess of PETG that blobbed all over the heat block today, tough little suckers they are.
I'd suggest waiting on the resistor idea to check the input until you can get a new thermistor to try. Doing that troubleshooting may be a bit sketchy depending on your confidence with electronics (anytime you mess with stuff like this you risk shorting things with a mis-connection). Though if you try a new thermistor and it still does not register, and you have ruled out firmware, as a last resort before swapping the board, it is worth a shot. I mentioned on my site that I do not recommend testing that way since it is far better to test the easy stuff first. I also just noticed that in my earlier post I suggested a linear taper pot (what I had) but I think an audio taper pot would be better for testing it (but again as a last resort type thing). That said, good luck with this, I hope it is not your board.
One more thing you can try as well if it does not work is to connect the new thermistor, then with the printer off, unplug the thermistor wires from the board and test that you get some resistance through them with a multimeter (on ohms), and you can even try warming the thermistor up with something like put it next to a hot cup of tea and see if the value changes. There is very little if any risk to testing that since it is all done with power off and the thermistor disconnected from the board. If it does show resistance which will probably be around 80Kohm at room temp and go down with increased temps, then you know it is not the wire harness.
Thank you!! I'll try it right now and get back to you!