Ender 3 V2 Auto power off shutdown

thingiverse

Auto off modification that will make your Ender 3 V2 turn its power off automatically when it is done printing. This is basically a holder for the power switch, and it is positioned so that one of the wheels under the print bed will flip it to the off position. This requires that you extend a cable from the power supply, and add some custom G-code to the end of your print. You need the cable itself, 3 female and one male spade connector. Use insulated spade connectors or heat shrink tube. Do not attempt this unless you are comfortable working with electricity. This is merely a documentation of how I would do it, and I assume no liability for damage, injuries or death caused by you.There are at least two different power switches for the Ender 3 V2. This mod will only fit the one I have myself, which is the long, slender type (see pictures). There are other similar mods that will fit various switches as well.This mod comes in two versions;Screw on: You need to unscrew the Y axis belt tensioner knob, place the bracket, and then tighten the knob again. This secures the bracket firmly in place behind the knob.Clip on: The bracket can simply be snapped in place from above and is held loosely in place.There are several ways you can route the extended cable. I used a fairly solid cable with thick insulation, and routed it under my printer for ease of access. It’s attached with one adhesive cable tie mount and some zip ties. The printer is already raised, so there is lots of space.The bracket should be printable without any support.Once you have it printed, start by disconnecting power, then unscrew the power inlet and pry out the power switch. Disconnect both the red wires from the power switch. Remove the short, red wire - we don’t really need that anymore. Add one female and one male spade connector to one end of the new extended cable. Connect these to the red wire and the now free terminal on the power inlet. Organize the cable so that everything is neat and secured.Route the cable how you want it and cut it to the correct length. The distance from the end of insulation to the tip of the longest spade connector should be about 35mm. There is a measurement imprinted on the bracket that you can use. You can also cut one of the wires a little shorter than the other to make everything line up nicely inside the bracket. See images for details.It might be easier to thread the cable through the bracket before adding the spade connectors. If the spade connectors have a long sleeve of insulation in the rear, you can also trim this down a bit to make it easier to fit inside the bracket.When the spade connectors are fitted, connect them to the power switch ensuring correct orientation of the switch relative to the markings on the bracket. Push the switch in place. I strongly recommend adding two zip ties like in the pictures. You do not want the cable to come loose from the switch and expose a live wire!You should now have a working switch in the front of the printer. Make sure that only the wheel under the bed is touching the switch.Next step is to add some g-code to the end of your prints. In Cura, this can be done by selecting preferences > configure cura > printers. Select your printer and click on “machine settings”. At the very end of the text field marked “End g-code” we want to enter the shutdown commands.The idea here is to keep the fans on until the hot end has cooled down. While cooling down, the print bed is moved close to the power switch. Once it has cooled down, it is moved the final stretch to trigger it. Our Y coordinates might not be the same (I am running the mriscoc professional firmware with some slightly modified bed dimensions), so I recommend investigating the Y positions yourself. This can be done by homing your printer and then adjusting the Y coordinates while observing the wheel position relative to the power switch. You want the pause position about 1-2 cm from the switch. You do not want the switch to stop in the middle position, so to trigger it, it actually has to move a little bit past the point where the switch flips over. The printer will have power for a fraction of a second after flipping the switch, so you also don’t want to go too far. While slowly increasing the Y position, you should add about 5mm to the value of the position where the switch flips over. ;Here is the G-code that I use:; Auto shut off modM140 S0; Turn off bedM104 S0; Turn off hotendM106 S200; Set fan speed to 200 (255 is max)G90 ;Absolute positioningG1 F1500 X20 Y200 ; Move X (printehead) to 20, and Y (bed) to 200M109 R30; Wait for the hotend to cool down to 30CG1 F1000 Y235 ; Move Y (bed) out to trigger power switch