Hey guys, for some days I have issue with my temp readings. First I thought this was because of the LIN_ADVANCE firmware and the reduce baud rate but it is also with the RC7 firmware I used before without issues. Heres a pic: The temperatures jump up and down by +-3° every now and then... Also the bed it seems but not by so much, just +-0.2°. I think this must be an issue with the RUMBA itself or the firmware or the amplifiers but I remember the bed was real stable before and now it is also not... The second hotend is not a real PT100 but just a resistor simulating ~21° so... After the current print is done I want to refresh the firmware and clear the EEPROM, then I will rerun the PID tuning and see if there is anything changing... Any other suggestions?
Oh BTW, I realised that when I turn the button on the LCD to increase or decrease the federate the displayed values also fluctuate a lot until I stop to turn the button...
Ok reflashing and resetting had no result... Then I unplugged all the stepper drivers and the temp were stable. I plugged them again one by one and when I plugged the Z stepper driver the temps did that jumping up and down again. So I changed the driver, nothing. I changed the firmware to use the E2 port for Z and a new driver, nothing. This sucks, as far as I can see the RUMBA has again an issue. Or why would a static resistor connected to the amplifier board jump up and down? Or why should both amplifiers be damaged the same way?
Sounds like interference, the z axis motors are almost directly above the pt100 PCB. Just to confirm you could try and swap the drives over (to X and Y), or even disconnect the motor on the right. If it's EMI (electro magnetic interference), it could be a winding on the motor on its way out. Alternatively, having re read your previous the voltage regulator for the PT100 amps, LCD and possibly the Pi could be struggling. Do you have a volt meter available?
I disconnected the motors too and the issue was still there... I used different and new stepper drivers... no change... I have a voltage meter but currently I have a print on the box I need until tomorrow. It works so far but the temp is not stable. I tuned the PID for the new socks and had a stable line. Today I had it like I didn't tune it, the line went up and down. I retuned them and no I have a low variation about +-2°... I think it is working because it is not really the temp but just the reading that has a problem. What shall I measure with the meter? My Pi has an external supply...
Hmm, we're the temperatures stable before you put on your socks? If so then it could be something disturbed on the print head, when you get the opportunity you could try and remove the sensor from the block. This would also isolate any earth loops (strange unwanted effects with having split supplies and different references (in this case for 0V). It's generally good practice to make sure all of your 0 Volt lines are connected together. This is especially important for Earth leads (floating earths) but not relevant in this case. For the voltage you'll need to find the 0V line (in general any black wire but not always) then the +5V line going to the PT100 PCB's. 5V or greater is fine, if it's less (even 4.9V) can cause some circuits to act in unusual ways.
https://forum.e3d-online.com/index.php?threads/pt100-temp-fluctuation.1222/ Not sure if it's the same but excellent advice.
This really sucks... I have no idea other than replacing the RUMBA... I exclude the amplifiers for the moment because all readings are influenced, look at this: Code: Send: M105 Recv: ok T:25.7 /0.0 B:23.7 /0.0 T0:25.7 /0.0 T1:20.5 /0.0 @:0 B@:0 @0:0 @1:0 Send: M105 Recv: ok T:28.4 /0.0 B:24.1 /0.0 T0:28.4 /0.0 T1:23.7 /0.0 @:0 B@:0 @0:0 @1:0 Send: M105 Recv: ok T:24.8 /0.0 B:23.6 /0.0 T0:24.8 /0.0 T1:19.3 /0.0 @:0 B@:0 @0:0 @1:0 Send: M105 Recv: ok T:23.6 /0.0 B:23.3 /0.0 T0:23.6 /0.0 T1:17.9 /0.0 @:0 B@:0 @0:0 @1:0 Four consecutive M105 of OctoPrint...
Ok I think I may have found it... The connector from the amps seem to have not so good contact, wiggle it a bit and its ok... Seems I have to remove the PINs and work on them with a plier...
UPDATE: SOLVED!!! I can't believe it... But again it was the connector. Basically the one to the RUMBA but I pulled all PINs from all connectors of that cable one by one and bend the lip gripping the PINs... Now my temp I stable again! Code: Send: M105 Recv: ok T:26.2 /0.0 B:24.2 /0.0 T0:26.2 /0.0 T1:20.8 /0.0 @:0 B@:0 @0:0 @1:0 Send: M105 Recv: ok T:26.3 /0.0 B:24.1 /0.0 T0:26.3 /0.0 T1:21.2 /0.0 @:0 B@:0 @0:0 @1:0 Send: M105 Recv: ok T:26.2 /0.0 B:24.2 /0.0 T0:26.2 /0.0 T1:21.1 /0.0 @:0 B@:0 @0:0 @1:0 Send: M105 Recv: ok T:26.1 /0.0 B:24.2 /0.0 T0:26.1 /0.0 T1:20.9 /0.0 @:0 B@:0 @0:0 @1:0 Send: M105 Recv: ok T:26.2 /0.0 B:24.2 /0.0 T0:26.2 /0.0 T1:21.2 /0.0 @:0 B@:0 @0:0 @1:0
But I think I'll stay with the dual Z stepper drivers, switched them to DRVs too and now they are better sounding and more holding torque...
Hi Alex, I have the same problem time to time only on my dual's right extruder temp is 10 to 15° higher than ambiant, then fans never stop once extruder is off. I usually use a contact cleaning spray on the connector and everything is OK again. I do this once every two weeks or after printer not used for a while. Problem lies in low quality connectors, and I think, amplified by pollution from fumes out of nozzle, and some other products, like the spray I use to make my parts perfectly stick on the bed, this is some kind of glue. Regards
