My Printrbot simple metal's extruder is jammed and I need to heat it up to unjam it. Unfortunately, the printer does't want to connect to my laptop regardless of the program I'm using (Repetier-Host or Cura 15).
Is there a way to use a micro SD card to heat up the printer hotend but not print anything?
Sure there is. As you use Cura, you can grab any G-code file (you already have) and use it to set hotend temperature (delete the actual printing part from the file) to get something like this:
;FLAVOR:Marlin ;TIME:102 ;Filament used: 0.0573674m ;Layer height: 0.2 ;Generated with Cura_SteamEngine 3.3.1 ; M190 S60 ;-> this sets the bed temperature so we can comment it out ; the next line sets the hotend to 200 degrees Celsius M104 S200
As every line that starts with a semi-colon is a comment and is ignored by the printer,
M104 S200, would be the only line you need in the printout file.
If you're interested in knowing more - look here: G-codes on reprap wiki