On today's episode I'm going to show you how to add a simple auto shutoff to your
3d printer it shuts itself off after the print is done and later when you come
back and you want to turn it back on it comes right back to life I'll show you
how to do it without any firmware changes on today's Filament Friday
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at the heart of my design is this high power relay that you can control with a
low voltage low current signal it's got some normally-on plugs and normally-off
plugs and you can control that by the signal there's also a always-on power
which we'll use as an option later in a video inside it's got a relay that can
handle 30 or 40 amps depending on which plug each use
it's got surge suppression it's got optical isolation it says it's got a
short-circuit protection and there is a reset on the switch so that's an implied
circuit breaker and it's got heavy-duty copper which is then covered with solder
flooding so it's really well built and I like the fact that I only need 3.3 volts
to control this so very low voltage can control high voltage to control this I'm
just going to use a Creality stop switch mounted at the top of the printer
so when the x-axis cross beam comes to the top it shuts off the printer
here's the schematic of what I'm going to build I'm using a 9-volt battery for
the low voltage low current signal and I'm using the stop switch to turn that
on and off and when it's turned on it'll turn on the printer
now I'm gonna make my own harness with this connector set and also I have this
crimper tool that I use I've used this in previous videos but I'm going to use
it here I'll show you another option in a little bit if you don't want to go
this route but what you do is you take the metal pin put it in the crimper and
get it pushed in partially and then you bring in the wire not stripped just
insulation and wire altogether put it inside the crimper squeeze this thing
and the crimper will actually roll the pin and cut in through the installation
and make a really good connection so then you take that and the locking pin
goes into the slot and it snaps right in place so then I just need to make a
second wire for the other side and this thing's ready to go now if you don't
want to fool with that you can buy switches with wire harnesses and these
are actually cheaper than the switches I showed earlier they just sell out really
quick I think they've only got 15 left in stock so that's an option I'll put a
link to this as well now I need to route this wire and I'm going to route this
through the channel at the back of the printer so I'll put it right inside the
channel here and then I've got this little insert plastic insert stuff I
stole it from another printer it snaps right in you can 3d print something to
go in here as well there's lots of 3d prints and Thingiverse for this but it
snaps in place holds the wire then I'm going to bring it down the upright over
here by the power supply but on the channel that doesn't have the power
supply screws going through it so another piece to hold it in then bring
it behind the power supply and then underneath the power supply all the way
to the back of the printer now I need to connect a nine volt
battery to that wire and the way I'm gonna do that is with these solder
sleeves I've used these in a previous video they're very handy
they're basically a shrink tubing with a solder blob in the center so you strip
your two wires put it to the halfway point
so both the wires are touching so the metal is touching but it's touching at
the solder ring and then what you do is you heat it up with a heat gun and it
shrinks the outer portions around the wire to hold it and then you hold it
there longer and then the solder starts to melt and solder is the two wires
together so it's completely sealed and soldered it's a great solution so now we
need to finish the circuit we just need to connect to the little connector that
pops out of the power relay and you can see that the left side is positive the
right side is negative so I'll put the positive on the left side and I'll
tighten up that screw and then we're gonna do the negative side and that will
complete the circuit so I'll take the negative side from the battery clip put
that in the connector and tighten that screw now some people like to put a ferrule
on these things I'm just using the bare wire it's gonna work fine it's low
current should be fine and then you just plug this into the
power relay but first I want to print this 9-volt battery holder to hold the
9-volt battery and here it is and I'm using double-sided tape on the back so
I'm just gonna stick it to the side of the power relay and then we'll plug in
the connector and then finally plug in the 9-volt battery and this battery
holder is a pretty good design because it slides right in and snaps in place
pretty nice i bundled up the wires and then tied
them with a tie strap so that'll hold everything in place
so now we need to install the switch this mount is a copy of the one that's
on the CR 10 or CR 10 mini found it on Thingiverse and i printed it out and it
fits to switch perfectly a couple of screws to hold it to the plate and in
one t-nut to hold it to the beam so I'm gonna slide this in place all the way to
the top and then tighten that T nut and then this will hold the switch just
above the crossmember as it comes to the top so then I'll plug in the wires
and this thing is together so now let's crank this up and make sure that the
switch makes good contact and it does with the bracket that holds the extruder
so now let's plug the rest of the wiring in there's a short cord that comes with
the power block so I'm gonna plug that into the printer and into a normally off
plug then I'm going to bring in the power plug and this is hot but I've got
the switch turned off so I'll switch it on and you see get a red LED but no
green LED which means that the signal is controlling it so then I'll turn on the
printer and still nothing the printer is not on
but as soon as I turn this down the switch closes and you can see the
printer turns on you get the green light and the LCD is lit now to make this work
I have to put one line in the g-code of my slicer file so I'm going to go to
manage printers my Ender 3 machine settings and I'm gonna End g-code now
this will work with any printer that you're doing this with so it's 250
millimeters I'm gonna raise it up at the end of the print so it's the last line
in the g-code I know that's hard to see so here's the full g-code but it's just
this last line g1 f3000 z250 it moves the z-axis up 250 millimeters to shut
off the printer it's the last thing it does
if you want to slow it down or give the hot end in bed more time to cool before
it shuts off just change that 3000 to say fifteen hundred or a thousand that
will slow it way down so now let's try it out here it is a real simple print it
finishes printing it homes it beeps telling me it's done and then the arm
starts to raise up trying to get to that 250 point it hits the switch it shuts
off and now when I'm ready to print again I just come here
twist the threaded rod machine powers up and I can go and print again so it works
and it works really well and the way I have this wired is the battery is
feeding power to the block during the print so that battery were to go dead
during a print it would actually shut the printer down so the other option you
have is to plug into the normally odd and then the battery would you'd have to
switch the wires with the battery would feed it when the printer is off and that
way the battery is actually feeding power all night long and so if it were
to go dead it would just turn the printer back on but it's not printing so
that may be a better way to go but I wanted everything off so I wired it so
the battery is off at the same time the printer is off and when it's on the
batteries on so there's one other option you can use a power adapter this is a
nine volt DC power adapter and there is one plug that says always-on so if you
plug this in to always-on it's on as long as the switch and the block here is
on and as long as you've got power coming into the block and then you can
wire this to replace the 9-volt battery so then you don't have to worry about a
battery going dead at all it's a little more expensive but it's probably better
in the long run but the nine volt battery to me was an easier way to
demonstrate how this works and to show how to hook everything up so that's the
way I did it and it's working fine for me so the options are out there the
choice is yours now I know this isn't the lowest cost option some people have
actually wired their own relays in the power supplies which is fine if you know
what you're doing with mains wiring I personally do not recommend
that because if you screw something up that's high current that could cause
problems where this has a circuit breaker and surge protection built into
it it's built really solid it's designed so low current low voltage controls the
high voltage so it's pretty safe to work with so this to me is a better choice
and under $25 I mean all wiring switches included was under $30 so to me this is
a very safe and affordable way to make your machine auto shutoff so if you like
what I'm doing here maybe check out some of the other videos that are popping up
if you want to help support the channel patreon is one way and if you need any
parts for anything I've done it any of my videos links are in the description
below and if nothing else click on that CHEP logo and subscribe I'll see you
next time right here at Filament Friday