Heated bed in CNC MODE

Giubba72

Hello guys,

the question is how: i can use my 3D printer (repetier firmware 1.0.0 dev - repetier host 1.6.2) in cnc mode (M453) without the heated bed connected? Repetier host give me a fatal error (heater/sensor failure), it would be possible to simulate a fake temp sensor in CNC or LASER MODE ? 

Thanks!!!

Marco

RAyWB

you can just mount  a dummy resistor (i use a 100kOhm) for simulating a bed temperature sensor.

(also for simulating Extruders).

@Repetier : wouldn´t  it make sense to disable the sensor check in CNC  and Laser mode

                    and for example Show coords including G92 Offset instead of temperatures?

Repetier

I assume you switch bed unconnecting thermsitor?

Simple solution is to replace thermistor with 100K resistor.

On long term I would need to make it not test temperatures at all in laser/cnc mode, but currently that is not supported. Hope I remember next days when I edit it. should be a easy fix.

Giubba72

Thanks guys!!!

Marco

Giubba72

The problem is the same with the extruder thermistor, when i mill the printer head is not connected.

BB

Marco

RAyWB

You can Handle that as follows (just tested on my machine because i have same "problem")

in extruder.cpp (should be line 351)

search for :

GCode::fatalError(PSTR("Heater/sensor failure"));



and replace that by :

  if (Printer::mode == PRINTER_MODE_FFF)
    {  
    GCode::fatalError(PSTR("Heater/sensor failure"));
    Printer::mode = PRINTER_MODE_CNC;
    Com::printFLN(PSTR("Changed to CNC Mode"));
    }
   

for me that works ;-)

@Repetier :

may be you can implement that as a preliminary solution , automatic switch over to CNC mode is necessary because
it´s not possible to change mode via Repetier Host

Repetier

Why should changing mode in host not work:

- M451 - Set printer mode to FFF

- M452 - Set printer mode to laser

- M453 - Set printer mode to CNC

Should change mode.

Only problem I see if you enable while bed is removed it would start in FFF mode and trigger the error.There your trick will work good, but with bed mounted and a real error your fix will prevent the failure. We need a better solution even if it is a bit more complex then.

RAyWB

"Only problem I see if you enable while bed is removed it would start in FFF mode and trigger the error.There your trick will work good, but with bed mounted and a real error your fix will prevent the failure. "

that´s correct but nobody will use heated bed or extruders in CNC or laser mode and also if you go back to FFF it will trigger the
error again.
As you know when its started in FFF and error is triggered you cannot change mode by Host, that´s the problem for universal machines.
checking temperatures/thermistors in laser or cnc should not trigger a fatal error

Giubba72

Thanks!

Marco