Ok I'm going to start assembling the new CNC
machine. I've managed to print all the plates,
although I might reprint this one as I changed
the joining mechanism. You can see an additional
semicircle here and there isn't one on this
side. I added another fixing point a little
bit further down here, and changed the way
these two pieces join. This was just because
of the footprint of my 3D printer that I was
actually making the plates on. I'm not going
to start with those yet. I'm actually going
to start with the gantry. So you can see the
way I've designed these so that space for
the heads of the machine screws that are holding
the pivot plate onto the Z axis, to move around.
In fact you still get the same movement that
you would if the machine screws were placed
in position. I've already put the grub screws
in here. This is what's going to trigger the
proximity sensors, and the back plate should
look like this and the opening should be on
the bottom right. And then the front of the
gantry plate have the grub screw holes at
the top.
This is the voice of oversight. You’ll be
hearing me periodically interrupting myself
to mention things I forgot to mention while
doing the thing I was doing. So, while I put
the gantry assembly together I’m going to
verbally explain the parts and positioning.
The top line of wheels uses eccentric spacers
while the bottoms ones are fixed. I happen
to have ¼ inch ones, but you can get and
use 6mm. I went for the cheaper parts. The
spacing is very simple. It is a fixed spacer
or eccentric spacer, a precision shim, a v-wheel,
a precision shim, a spacer, two precision
shims, a wheel, a shim, and either a fixed
spacer or eccentric spacer.
So the thing to just mention at this point
is that, between the spacer here there's one
shim on one side but two on the other. Opposite
wheels. If the wheel doesn't pop down it might
be because the shim between the two bearings
has slid out. Just use a stick or something
and push it to one side. I think I'll actually
put the nut block on as well to make sure
I'm not putting it on the wrong way around.
Ok these are 25mm M5 machine screws, and they
hold the nutblock. I'm missing the spacer,
and I'll just workout what that's supposed
to be. This is great, I'm reading my own instructions
because I've forgotten.
I’m placing the anti-backlash nut block
onto the rear gantry plate before assembling
the section. I intended to space that with
4 precision shims but later on in the video
I realised I needed 5 to line everything up
properly. When I first made my original CNC
machine with ply plates, I also made the nut
blocks myself so the spacing between them
and the plate wasn’t so crucial as it was
bespoke. But I wanted there to be an option
with this machine to use shop bought nut blocks.
Ok that's good. And then you have the access
for that if you need to tighten it up.
I then placed the final fixed and eccentric
spacers in position on the opposite plate,
and assembled the gantry section.
Ooooh they're cutting really well now. Ok
that's pretty good. So I got this from Ooznest
and asked them to cut it to size and it's
bang on. So now this just slides on like that.
I’m now fitting the gantry to the c-beam
aluminium profile. This involves adjusting
the eccentric spacers at the top of the assembly,
so all the wheels are running along the aluminium
but ensuring they are not too tight.
So I've already put this together, making
sure the Z axis aluminium extrusion is in
place. When I was screwing it on I pushed
it to one side just to keep it square.
I haven't tightened it all the way so it's
pivoting.
Ok this is the z plate, woh, and those are
the nuts. These fit on like this and bolted
on here. But what I'm going to do first is
start to assemble the the wheels.
Here I’m using 30mm M5 machine screws with
either an eccentric or fixed spacer, a shim,
a mini v wheel, and a locking nut. I'm using
this to push the eccentric spacers in and
then I can fit it onto the C-beam z axis.
The notch is facing outwards for these four
and inwards for these four. And what I'll
do because I've locked these down, I'll adjust
the first and second one. If it's a bit too
tight slack it off. You don't want to force
it in. When you drop it in, you want to be
able to feel the wheel moving. I'm just doing
the other wheels now. Turning it till I see
it moving. Ok that's feel good.
When you’re happy that all the wheels are
in the correct position, you can do a final
tightening of the nuts.
The next thing I'm going to do now is screw
these sections in. That's not going in. Aaah,
so these are rubbing on the bit here so I'm
going to have to change them to low profile
ones. I've just put on two on for now. Yep
so, that was the problem so I'll have to take
these two off as well. So that's all four
of them. I've left the two as they are, because
that shouldn't get in the way (wrong).
I also changed the centre spindle mount machine
screw which would be hidden by the anti-backlash
nut block, with a 35mm low profile one as
this was obstructing the not block.
Yeah ok so that's not going to work.
So I had to take this part off so I could
get the allen key in. These are long ones.
I specifically bought because I knew I'd be
using them for things like this. If you find
it difficult to tighten up, holding the short
end you can use a pair of pliers to hold these.
Ok that is very close there.
If feels super rigid (it's super super rigid),
and like the gantry plate I've up a grub screw
in here which will detect the pivot plate
(I meant proximity sensor). These are the
688z bearings, and these are going to help
keep the tr8 threaded rod in the right place.
I'm hoping I've done this correctly. If it
was off, if it wasn't centred properly I shouldn't
be able to pull down that far. Although when
I do line that up, the top plate is a little
bit far forward, I could push it back. I think
it's going to work. This is the washer or
the shim that goes on top of the, 688z bearing,
which is this one here and the locking collar
goes on top. This isn't from any CNC place,
this is actually a seal washer which is for
plumbing. I'm just going to put the washer
at the end of a pair of mole grips, and then
by hand take an 8mm bit, and that'd made all
the difference.
The next thing to do is assemble the Y Plates.
I printed these out in two sections because
my 3D printer wasn't large enough and after
bolting them together I began to fit the wheels,
bearings and nut blocks.
I think that's going to go that way... Nooo,
you're wrong it's the other way. Is that right?
No that's wrong.
I've just realised I've made a mistake which
means I'm going to have to go print another
one out. It's really silly because I wasn't
paying attention. Essentially the opening
for this nut block, means that when it sits
in this position I can access the grub screw
which tensions the thread against the nut
block. But when I went to print these out
I must have flipped this design in Cura, instead
of exporting the opposite side. And you see
this positioned here, the opening for this
plate should be lower down so it's in line
with the grub screw. Just an oversight. I
knew this and added in into the design but
there's only so much you can keep inside your
head. So I'm going to have to go back an print
these out.
A coupe of 25mm machine screws. And five precision
washers. So I've put all the wheels on, they're
a little bit loose. It just means I can adjust
the spacers to make sure there's a snug fit.
Ok I've just done the opposite side. You can
see there's a slight difference here if I
turn these around. That is the opening here
are set apart and it's because the nut blocks
when you turn those around the grub screw
changes position. Ok these are seating pretty
well. There's no noticeable wobble and no
gap between the pieces.
I’m now finishing the assembly of the Y-Plates
to the C-beam and the lower 20x40 support
profile but I have to tap some holes first.
Then just to make sure that this remains nice
and flat I'm using a large drill bit to take
off the raised edge at the top there as the
aluminium gets pulled out a little bit.
You need to remember to put the nuts in on
the side that have the stepper motor. I think
originally I had it on the right hand side,
which is that side but this time I may put
it on the left. And I have to remember to
put the 20x40 in the bottom side. So these
two pieces here have been cut exactly the
same size.
I later managed to break a bit in the aluminium
which I couldn’t get out. I will show that
later in the video but if you’re following
along I would recommend to do this by hand
or get the correct bits for use with a drill.
So there's a bit of flex in the y plate but
then again I haven't actually tightened this
section up so you can see how the pivoting
mechanism works. this is where I begin to
run into problems because my work area is
not big enough. Lets see what happens. I was
rushing tapping the holes in the other pieces
of aluminium extrusion and my tap just broke.
You can just see it poking out right there.
I decided to cut the two pieces of c-beam
down to 670mm using my table saw sledge and
extension arm. I would also cut a few lengths
of 20x40 profile down to use later as supports
for the waste-board.
I probably could have done it 68 but I might
have nipped the end of that bit. Anyway that'll
have to do.
These are the re-cut x axis c beams and I
want to re-tap the ends and I'm going to do
it by hand. No machine, nice careful, one
rotation forward, half back. Ok I'm going
to reassemble everything again. I might be
easier to work on my table saw but lets start
anyway. If you're going to use a hand drill
make sure you drop the torque settings or
trip down quite a bit.
I’m now fitting the front and back motor
plates, and then sliding the horizontal support
20x40 profile piece, not before undoing the
motor plates machine screws to pop a couple
nut into the countersunk nut areas between
the plate and the c-beam, and sliding 4 t
nuts along either side of the y plate c-beam.
Because I forgot.
You can make these quite easily. Buy 3mm aluminium
L section, a meter for about £7 but I just
3D printed these. I didn't have time to wait.
Ok the next thing I'm going to do is put the
wasteboard on and these pieces of 20x40 aluminium
extrusion. I haven't quite worked out the
best way of doing this. Really I should have
cut these shorter, and had a another pieces
going across with corner brackets and then
the MDF on top of that. I've done it a little
bit differently. My wasteboard is two pieces
of 18mm MDF, with countersunk holes and some
channels in the back for the aluminium extrusion.
I got that cut externally, it's a little bit
more complicated like that but in reality
it could be a piece of aluminium and a waste-board
bolted onto that. I think that would have
been the best thing to do. Anyway here 
I am.
I'm going to do the rest like this and I think
I'll try and lift he board into the position
around the back. It's a bit of an awkward
way of doing it.
Eeer... Got a
tool for everything.
There's a couple machine screws I need to
put down here.
It's getting heavy now.
I think this videos come to an end now. The
machine is more or less assembled. I'm missing
a couple things like the bracket underneath
this piece of c beam, which will create a
positive shelf essentially, for that to sit
on. Everything seems to be move really well.
Obviously this is a prototype. I don't think
PLA really is the material to use over a long
period of time. But I think I'll get some
cuts from this. It really depends on how warm
the spindle gets. In this particular section
here. Maybe the first thing I'll try and do
is re-cut these out of aluminium. Maybe it's
wishful thinking but if the previous machine
managed to do it, I feel like this one should
as well. And the advantage I'll have with
this, is I'll be able to properly tram and
square the machine. I'll have the hard limits
at the front. which I'll be able to keep it
square and make sure if I do go off for whatever
reason, I can always bring if back and square
it. And because I can pivot teh spindle along
the x and y axis it should really minimise
any errors that can manifest from cutting
on the CNC machine, so I'm feeling really
optimistic.
In the next video I’ll start to dismantle
the old CNC machine and prepare the electronics
to be coupled onto this machine. So until
then, thanks again for watching.
