Temperature problems

Yesterday I tried to install a firmware that Bigtree tech asked me to put on there in response to my support request. The firmware renamed itself to .cur so I guess it took but the firmware version didn’t seem to change. I didn’t print anything until this morning. It was a small part, 2 hours to print and I noticed when I checked that the Z depth was too low and the first layer seemed really thin like it was smooshed 9it had a brim). the print came out ok in the end and went back to tune the Z height. It seemed like the nozzle was clogged and didn’t seem to clear easily so I changed it. This seemed better so I let ABL relevel and save itself and tried a plane test and the height seemed too high this time. the filament was round and not smooshed into the bed at all so while that was running I baby stepped it down but the filament never stuck. so I tried feeding filament and got skipping, like the nozzle wasn’t hot enough so I put a temp probe on the heater block and it was reading 25° too cold so I started PID autotuned and it errored out after a few minutes. It just said process aborted. I did that a couple times and never got it to complete. What else can I check for?

@Glenn That sounds super frustrating. To be honest I have no idea. My only comment is a generic one. thermistor I am guessing is a thermal resistive sensor. If it is changes in the wire can change the temperature. I have never tested this with a 3d printer but a probed resistive sensor I have. A damaged wire can change the electrical resistance and change the way it is read. I think that is completely unlikely but it is the only thing I can think of.

Personally I would swap it out and see if it changed at all. It is a quick diagnostic, if nothing changes it eliminates that as an issue. You can always use the old again.

Yes i’ll have another look at it tonight. I got sidetracked today. What’s irksome is I changed the firmware (or might have changed the firmware) and at first suspected that it wiped my settings. so now I’ve done that and changed a few more things and have no idea which thing caused this temperature problem.


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Can you post pics of the problem please

I have pics of the screens during pid tuning failures? Is that what you want to see?

I took the filament path apart in this and it’s all back together clean and tight. Looked inside the housing and the only thing amiss is the way this wire bundle is touching the heat sink and looks like it’s melting. I’ve been printing mostly PETG for the last week so the temperatures been set around 240. I have all new parts coming for this including the metal kraken heat break, aluminum Volcano block and nozzle I hope I can bundle that wire away better than it is. But getting it apart I had the opportunity to probe the parts for temperature and the heater block is always 25° colder than indicated., I did not take it apart to see if the thermistor was out of place or anything. it all seems tight.


So BTT sent another firmware by mail. the PID autotune function still doesn’t work but it seems I have control over Z height again. I forgot to measure the nozzle temp I’ll do that shortly. The firmware has changed the menu selections on the BTT screen. One is the same as the manual the other … is what I have. PID autotune did work before, there must be something in this firmware that is breaking it. What is the best way to look at and compare the firmware I have? If I go to GitHub I can find lots of firmware but not many “official” ones I think it’s best if I dive in and learn what these scrips have hidden inside.

BTT is suggesting the cable is the problem with the BLtouch… I don’t think so, there’s no evidence of that. No word on the 25° too cold issue. my new hot end parts are here so I’ll have it apart this weekend. Turns out I forgot to order some stuff. I must have deleted the items from, my cart by accident.

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I hate it when I miss something. I tend to have spares on hand my free time is short these days so spares are relatively less expensive.

yeah, I was going to add a smart filament sensor and hardened nozzles. when they didn’t come I looked at the packing list and realized I hadn’t even ordered them :confused:

The sensor is the big tree one? It looks interesting. Let us know how that goes. I used hardened for a while but I found they were slow to heat and I had to set temps higher as they are poor at transferring heat. I compromised with stainless.

Check out the USB C cable where it connects to the back of the printer. On my B1, the connector came loose. It looked like the connector had bad solder connections, and. All the hotend circuitry goes thru that cable including the heater, fans, and sensors. I started experiencing parts not sticking as a first symptom, and then I experienced all kinds of weird errors after that.
For your height issues with the layer height varying, a possible suspect could be the Z-stop switch (defective or bent), or the height adjustment screw and mount. If the spring is too loose, the screw can wiggle around and your height can vary. Hope this helps.

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I will check that today. Thanks

So far so good. All the connections look ok and have it working well again. @PJprincefpv had me remove the sensor pin for inspection. I didn’t see any issues so I put it back in but tightened the set screw which I see now is an adjustment. I reset all my previous tuning and it’s working as well or better (ill see on the print thats in there now) It’s been a few days and no BLtouch errors except for ABL being turned off after every print. So I’m ready now to start playing with firmware. The print turned out better than I was getting before. it helps with the shiny PETG shows defects easily.

Is it possible to save all my tuning settings and reinstall them in a batch after updating the firmware?

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on the temperature issue. They’ve (BTT support) asked me to install another thermistor to try but they suspect the motherboard is the problem. so I guess I have to buy one to try and let them know what happens. Also they are going to send me replacements for my fans.

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