today we're going to learn how to install the A4988 for 3 extruders on the
Rumba 3d printer board so I need to point out a couple of quick things here
before we get going we have our first extruder port which is e 0 our next one
which is e1 and our last one that is e2 now I've marked the ground pin for the
corners here so that we know where it is located because I'm the bottom of the
stepper driver there is actually a ground pin that we need to line up so if
you haven't seen my first tutorial on how to install the stepper drivers I
suggest you watch that but one thing I want to let you know about is that all
the microswitch jumpers have to be in the down position
they're actually switch positions in this case and that says on right next to
it so it will install these what we're gonna do is we're going to line up the
pins apply a little bit of thumb pressure and then we'll do the next one
and finally easy row for the first extruder then to set up the motors what
we need to do is take the DuPont connector and connect it to the four
pins over here now you also have the option of using these screw down blocks
but for this case for simplicity we're just going to use the DuPont connectors
so we're gonna take the next one line it up and push it down and then we'll do
the very last one which is the different size motor but that's ok we're just
doing this for an example and line it up and apply a little bit of pressure so in
a moment I'm going to show you in Marlin
how to load the firmware but before I do that I'll show you how to set up the
serial USB okay in order to set up the serial USB we need to connect the small
end to be Rumba 3d printer board and the big
end to the computer and you'll hear a beep and in a moment I'll show you how
to load the Marlin firmware okay the first thing that we wanted to do is we
want to open up the Marlin - bug fix - 1.1.9 we then want to open up the marlin
subfolder we want to open up boards.h now what we're looking for in here is
board underscore Rumba so we're gonna copy this and we're gonna close out then
we're gonna press M on the keyboard and open up the Marlin.Ino file I want
to go to the configuration.h tab and we want to search on motherboard and what
we want to do is replace Board_Ramps_14_EFB
with what we copied out of the boards file so we'll paste it
here next thing that we want to do is scroll down and find the number of
extruders because we don't have one extruder now we have three we're gonna
change this to three well scroll down a little further and in this case we're
gonna say that we're using a single nozzle so define single nozzle will
remove the comment and then we'll skip all of this
now for thermal settings currently we only have one thermistor that we need
for a single nozzle so what we're gonna do is double check to make that sure
that we have one selected I normally use eight from the list above which is right
here but yours may vary so find it in the list and then in this case we're not
using a heat bed because it's a simple example so we're gonna skip over that
now the maximum temperature for heater zero would be in our case if you're
using PLA probably 215 Celsius but abs may vary so consult your packaging but I
prefer to keep it under Fahrenheit 451 or what is it about 210 degrees Celsius
so that nothing will catch on fire near by the printer and I always watch your
printer when printing and then we have temperature bed controls which we're
going to ignore for right now and then cold extrusion I'll show you a
workaround so that we can test it that'll be in pronterface we'll actually
use the G code to do that and then I wanted to show you thermal protection
this is a way that if you're not getting good readings that your printer will
shut down for you so if your thermistor is broken it'll stop your printer from
actually heating so that you don't accidentally overheat and cause a fire
so leave these alone next thing we want to do is search for steps per
now four steps per as you can see right here we have X Y Z we have e1 e2 e3 and
e4 as additional extruders that we can use but in this case we're gonna pretend
that all the steppers are the same just for simplicity and so we're gonna check
first to make sure that we have our COM port selected and that we have the
right chip set which is the MEGA 2560 so we're gonna press the compile and an
upload button which is the upload button in this case in a moment in Pronterface
I'll show you how to test it okay off camera after loaded the Marlin firmware
I disconnected the USB and connected the power cables for the positive and the
negative or the voltage and ground for 12 volts now it's unplugged so we're
gonna energize it now now keep in mind this is gonna have power running through
it so you don't want to touch the board when it's energized so in a moment in
Pronterface i'll show you how we're gonna test it
okay the first thing we want to do is we want to open up the Pronterface
executable and we want to connect to the printer and at the moment we only have
one extruder to work with so to change that we go to settings options we've
been then go down to extruder count and change that to 3 press ok close the
application reopen Pronterface now let's reconnect and as you can see we have
three tools to choose from now so in order to actually get an extrusion to a
occur, because we have cold extrusion limits we have to do a G-code to get
around it so we have to type, "M302 S0", and what that says is set the
temperature level for the minimum extrusion temperature to zero so press
enter and what I'm gonna do now is I'm gonna test the first extruder so I'm
gonna give you a moment to watch this after I press extrude so here we go
okay that was the first step now let's try the second one
and let's try the final one
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