Comment on [Troubleshooting] It's the clog guy again - temp readings are bad!
morbidcactus@lemmy.ca 2 months ago
One word of caution re IR thermometers, the emissivity of the surface you’re aiming at is going to massively impact its reading. From earlier photos it looked like you have a nickel plated block, most IR thermometers are preset to expect a 0.95 emmisivity (1 being a perfect black body), bare metals tend to be closer to 0 with polished nickel being 0.05, oxidised being in the middle 0.5 ish. Why I mention this is unless you are adjusting the thermometer for the expected emissivity it will totally underreport the surface temperature.
Other thing to consider is that surface temp and midblock temps can differ, forced convection from fans will totally contribute to that. Definitely like your idea of an accurate prove thermometer, I’d be super wary of changing your pullup resistance base on the ir reading, could definitely have it way too warm. Short term, you could try running with a higher temp setting. Have you probed the pullup resistor on the board?
Some thought that I wish I had considered earlier, sudden failure with no warning would definitely point me at electrical stuff. Might be worth considering swapping to something like an skr mini which is super accessible and is drop in replacement more or less for something like a Rambo board.
papalonian@lemmy.world 2 months ago
Yeah, I knew from the getgo that the IR thermometer was only gonna get me within a wide range of accuracy. (Hence resorting to more empirical testing like boiling water in the previous post, haha.) I was only using it initially to get an idea of where it was.
After posting yesterday I went out and got a high quality probe thermometer. I was actually lucky enough to get one who’s probe is the same O.D. as a Bowden tube, so it friction fits inside my hot end. It took a little while to find the exact spot in the probe that reads the temp, but I was able to dial it in last night to where both Klipper and my probe read exactly 200c. (Before adjusting anything, Klipper would read 200c, IR would read ~90-130, probe reads ~170.)
I’m not familiar enough with electrical components/ readings to determine anything myself, but I had a buddy over yesterday that was helping me out who went to school for the stuff and is very well versed with 3d printer diagnostics, and he verified that nothing on the board is reading out of the ordinary. I considered a new board, but the board I’m using currently is itself relatively new (just had the manufacturer send me a new one after the original died; new board has been working for ~2 months).
morbidcactus@lemmy.ca 2 months ago
Totally get not wanting to swap the board if it’s that recent and been in serviced for that long. Super strange it’s seemed to have drifted that much, could think of some last ditch things like changing the position of the thermistor, ensuring it’s centred in the hole, set screw tightened enough but not enough to deform the sleeve but I know you’ve rebuilt and changed all the components a bunch of times, honestly could even just be your batch of thermistors, but it sounds like you have a way forward now.