How to use Start and End Gcode Scripts - 3D Printing 101 Video Lecture | What is 3D Printing: Basic Knowledge - IT & Software

when it comes down to it 3d printers are
actually pretty dumb machines all I know
how to do is follow the commands that
you send to it when you slice your 3d
file in your slicing program this
creates what's called g-code a very
widely used numerically controlled or NC
programming language which has a set of
waypoints and commands that tells the 3d
printer exactly what to do when you send
files to your 3d printer you might have
noticed that the start and finish of the
print it does various things like it
might home itself or it might extrude a
bit of plastic to prime the nozzle or
might even present the part by moving
the bed fords at the end of the print
these are called start and end G code
scripts and today's 3d printing 101 is
going to be all about how you can create
your own and modify them to get the best
prints possible let's get started
welcome back to 3d printing 101 here on
Magus muse guys so before I get started
I need to stress that this is not going
to go into detail on g-code what it is
and how to use it because that's a very
advanced topic instead this is more of a
beginner's guide to start and end g-code
scripts in your slicing software and how
you can better understand them and make
tweaks as necessary so keep that in mind
if you do understand what g-code is this
video might be a bit basic view but
let's dive into it so what I'm gonna do
first is I'm going to add a process
within simplify 3d and it's going to
grab a random one for example my one
held typical a3 process here like that
this is a menu you'll be very familiar
with within simplify 3d on how to tweak
your settings in your print but I'm
going to show you a menu that you
probably haven't even visited before if
you go along here towards the right we
have scripts and scripts are very
important because this is where we can
alter us start and end Jean code scripts
so what happens is when we slice our
file simplify 30 we'll insert this
starting script here and at the end of
the g-code after the prints complete it
will insert an ending script now there's
a few other scripts you can use such as
layout change where it will fire off a
script every layer retraction as well as
tool change if you're running multiple
print heads but we're not going to go
into those in this video because they're
a little bit more advanced so let's have
a look at the study script for the one
Halep duplicator a3 so here we have a
g-code g28 and what g28 does for most
printers is they will home the axes
which means the print head will move its
x y&z coordinates to be at home position
sureness there's also a semicolon here
and home will axes that's a comment so
if you're doing g code you can comment
from what you're doing so people can
more easily understand what you've
actually done so i'm going to show you
here what that actually will look like
alright then so that's what g28 looks
like let's have a look at the ending
script for the one how I three so what's
going to do is G 28 but here instead of
homing everything it's only homing X
zero you can see G 28 X zero it's only
going to home the x-axis and this is
good at the end of your print because
you don't want the printhead to be just
stopped right at the last layer of your
print because then you'll lose a little
bit it might stick to the part as the
nozzle cools down and yeah you generally
want to move the nozzle out of the way
when the print finishes and then m-104 s
zero it's turning off our extruder which
is important we don't want to extruder
saying hot after the prints complete and
then M 140 s zero it's turning off the
bed heating as well and finally m84
means it's going to disable these
stepper motors so when the prints moving
the set motors are energized they do
warm up and take current to keep them
locked in position but when the prints
complete doesn't need to do that anymore
so it will turn them off to save power
other common G code commands include G 0
and G 1 these are movement commands and
used interchangeably with in Marlin
firmware so in the example G 0 X 20 the
extruder would move to the coordinate 20
millimeters in the x-axis you may also
want to employ m106 which controls the
extruder cooling fan speed using the S
modifier for 0 being off and 255 for
full speed so for example entering m106
s 0 into your end script would turn your
fan off once the print is complete and
just in the off chance that this sort of
stuff really interests you I highly
recommend checking out this humongous
list on the rap-rap wiki so this is a G
code list for almost every firmware
version out there keep in mind that not
all codes work for every printer
firmware but it will say which works for
which so here we got the the movements
so obviously the movements work for
every firmware listed here but then for
example m600 which is a filament change
pause here which I have been starting to
use on the puter i3 mark 2 you can see
that it only works for some firmwares so
even though this stuff's very
interesting and it is very much opening
a can of worms so you decide to dive
into it I'm not going to go into it any
more further in this video but if you
don't learn more about different G codes
you can
try on your printer hit this list up
I'll leave a link in the video
description so thanks for watching guys
hope you found this video useful and I
hope it demystified what start and end
scripts are and hopefully you get an
idea of what you can start tweaking so
as I said at the start this video this
is by no means meant to be an
introduction into the wonderful world of
g-code it's more meant to show what your
printer is doing before and at the end
of each print and what you can change to
get the best prints possible and a big
thanks to typify 3d for sponsoring this
video here on makers views I look
forward to seeing again very shortly
catch you later guys bye