Decoupling error

WhoopeR

Hello,

I managed to build my first printer, its based on Vulcanus V1 CoreXY printer and i have successfully managed to print small prints. Yesterday i tried to print a little bit longer print (approx. 30min) and about after 15-25min printer gave me following error on Repetier Host log: "Heated bed: working marked decoupled" and its set printer to Dry run mode, extrusion stopped, heaters turn off, but still continues printing. It's still reading values from thermistors.

Im using Repetier-FW 92.8

Any idea whats causing this, i tried to search google and forums but couldnt find anything specific for this error message.

For some reason i have to use pretty high (240C) temperature for Black PLA filament. (maybe wrong thermistor setting) but smaller print was fine and quality was pretty good for 10 min print on same temperature. Bed is running 70C as i dont have insulation under Heated bed yet and glass on top of it so i need to keep it little higher now for part sticking well to glass.

Repetier

Check your log. It should exactly say why it issued the decoupled flag. It is either heating up to target did not occur fast enought or you left target range. Then you can increase the values in your configuration so it does not get a false decoupled signal. As a last resort you can set doubled time to 0 whcih disables the test, but since it is a safety gain if it is configured correctly it should better just tweaked to work.

Can your bed also reach 75°C? Otherwise it could be a problem never reaching target temperature. You need to go at least once over target temperature to stop raising period. If raising is on while you hold this would also trigger the signal.

WhoopeR

Ok, Log gives me following lines:

"Heated bed: Working marked decoupled"

"Printer set into dry run mode until restart"

I'm using Bang bang method with heated bed heating.

It gives those error messages 2 times on log and then continues XYZ movement but extruder heater, motor and bed heater off.

I'll try to make some graph from HB values today evening. Or is there in repetier-host somewhere setting to display and save full log from single print or for heater temperatures?

I'm also thinking to change whole printer to run 24V as its running now 12V so that should give a little boost for heated bed i think.

WhoopeR

Here is the full log when it happened:

23:13:21.090 : Other:: working
23:13:21.090 : heated bed: working marked decoupled
23:13:21.090 : Error:Printer set into dry run mode until restart!
23:13:21.090 : ok 15170
23:13:21.090 : Other:: working
23:13:21.105 : heated bed: working marked decoupled
23:13:21.105 : Error:Printer set into dry run mode until restart!

Here is image of temp.curv when it happened:

https://flic.kr/p/Ea2Vhk</div>

Repetier

<font face="Arial, Verdana">I expected a different error message where it happens. One says deviations is x °C.</font>

Anyhow the curve shows a clear problem. Bed cools down while heating is at 100% so this is in deed something that can call a decouple message. Could it be that it starts to cool down when the fan turns on? Anyhow assuming you reached the 70°C at all it is

#define DECOUPLING_TEST_MAX_HOLD_VARIANCE 20

If you never reached the full 70°C it is

// Time is in milliseconds! Set 0 to disable #define HEATED_BED_DECOUPLE_TEST_PERIOD 300000