Heater issue: Heater extruder not heating at expected rate
Hi. So, I been having this issue randomly for some time now and it's driving me crazy at this point.
My VCore has been working fine with the Rapido (not UHF) for some time now and I have been able to even print for 40 hours with no issues whatsoever. However, for the past three weeks I haven't been able to print not a single thing because of the verify_heater issue. I can see on the Mainsail graph that once the temperature I use for PETG is reached (245), it randomly ramps down between 20 to 40 degrees and most of the times is not able to catch up and start printing.
I have searched around here for this same issue and tried all the options I have found: Redoing PID calibration, changing for loose/broken cables (I even changed cables from another Rapido), changing the thermistor and even replacing the heating cartridge but nothing works, I will always end with this same issue at some point. Usually happens before starting a print, but it also happened mid print multiple times.
I have attached both klippy log and printer.cfg. I don't remember changing any config parameter that could break the printer, but at this point I don't know what I'm missing here
13 Replies
For reference: the printer was able to start now a new print, but something's not right with the temps, as it went up to 265 after reaching hotend temp and I can see that there is indeed a lot of stringing and blobs in the printing (see attached picture)
rival-black•10mo ago
You might want to consider changing the thermistor to another header on the control board
I've just made the change and I'm running again a PID tunning and some more tests after. I will update it with my findings.
Thanks for the suggestion. As I have been tinkering with a different board this past weeks I totally forgot that the octopus has 4 slots for thermistors 😄
frozen-sapphire•9mo ago
Hi! I am having similar issues, did the change on the control board work for you @flyingonion ?
I think it fixed it but I cannot confirm yet. After changing the thermistor to another header the pid and the heating seemed to be stable, but I found out that due to the temp rising a lot some of the PETG parts of the hotend support started to melt and led to my hotend crashing against the bed, breaking the heatbreak.
I had no time to check this until yestersay and I'm getting a replacement tomorrow. I will try to update as soon as I make the change and see no issue here.
frozen-sapphire•9mo ago
Thanks for the info.
@topchicken6277 I've just made the change on the heatbreak and seems it's working fine now. To verify that it was indeed fixed by changing the header in the board I've kept the thermistor that I had earlier. So now it's not doing strange things with the temps and prints fine. 😄
frozen-sapphire•9mo ago
Thank you! This is going to be a stupid question perhaps but I tried the same and now I get MCU shutdo: ADC out of range error. Do you need to change something in the config?
Yes, you will need to change the sensor_pin in you printer.cfg so it points to the new connected pin in the board
@flyingonion sry but how does it work. To change the pin?
You need to change the sensor pin in your printer.cfg file. Check the datasheet of your board (I have a BTT Octopus), and use the name of the new port where you connected your thermistor.
In my case looks like this:
@flyingonion thank you very much :chefkiss:
@flyingonion but didnt help still the same error