Hello we're going to be talking about the Allett C34 and we're going to be talking
about the cartridge and how that fits into the machine to make sure that we get longevity out
of the machine as little vibration as we possibly can and as long a life out of the product as we
can but it's all about accuracy and you need to understand some of the detail of this cartridge
and its interchangeability. So there are several factors of the cartridge that insert into the
machine that we need to understand. First down this side is where the drive comes so the drive
comes through the chain case here and then we have a clutch system here which engages
to give the drive to the cylinder so we need to understand about that. The way that the cartridge
sits in the machine is absolutely critical. The machine sits on four rail points two at
the back and two at the front but there is also another point which sits just here which holds
the cartridge from lifting and lowering. The other contact point is just on this side which
is the the knob that screws into the side that pushes the cartridge and retains the cartridge
in its drive position. So this is the cylinder cartridge removed from the machine so we can
now look at the detail of how the cartridge sits within the cavity of the C34. So I talked about
the four points that the machine sits on and you can see those more clearly now the machines
removed. That's this point, the back of this rail, the same on the other side and you can
see at the front as well I'm just going to move over there. Importantly there is a spacer that
fits here and this spacer needs to be flush up against the side. You can see the drive
coupling just in here and this is the point on this side of the cartridge which engages.
There is a higher point just up here which when the cartridges move sideways along the rails to
locate against the drive coupling there is a noggin on the side of this side plate which
slips and engages here so that the cartridge is completely locked into the machine. The
final part of the cartridge engagement if you look at the side of the cartridge you
can see the points that the rails sit on the side plate but finally once the cartridge is
sitting on the rails and now needs to move across the machine to engage with the drive
we use this knob just here and that engages exactly and precisely with this point here.
So when I lift and insert the cartridge I'm going to make sure that I insert it to the
left-hand side of the cavity and it sits on the rails over in this side because I'm later going
to push it across once it's on the rails to engage with the drive coupling; so here we go.
So those sit very nicely and very accurately onto the rails and it's important this time
that we understand that because it's sitting on four points that they are all exactly level if
they're not then there's something wrong and we'll need to make an adjustment but there as
this cartridge stands it's sitting exactly flat on all four points. So we now will need to slide it
across to engage the drive coupling so I'm going to first align the drive couplings so that engage
cleanly and I can do that by rotating the cylinder and then once I've done that I can now turn this
knob which you'll see now the cartridge actually starts to move sideways and if I have the coupling
lined up correctly which I have then that will press home. In its simplest format I'm just going
to make sure I've got that completely tightened up. I can if I want to just make especially sure
that it's locked I can actually just give that a small tweak on this nut here to make sure that's
completely locked off. In the process of moving across sideways it's not only engaged into the
drive coupling but it's also engaged into the noggin on the side of the side plate to make
sure that the unit cannot lift so what can easily happen is that with changing cartridges between
different machines of different ages is that we can get a situation where the thread on this knob
is too long and we start to push and overload that cutting cartridge too much that can give cutting
problems and it can also give vibration problems so if you just watch this as I tighten this knob
which thread is too long you'll notice it starts to preload the cartridge too much and the side
plate starts to bend outwards so just watch this see if you can see this happening. So if I turn
this and perfect tension here but now I'm starting to tighten it more and you'll see the side plates
start to bow out we've just gone too far with the tension and we'll be starting to take the cutting
blade contacts out of where they should be either too close or too far away and cause vibration of
the cartridge as we preload the drive coupling on the other side. So if the thread is too long
on this it will preload the cartridge into the drive side but it will also cause the bowing of
this plate out so I need to make some adjustments here and the best way to do that is by taking an
allen key and actually tightening this up so it's just the right amount I need it to be snug enough
to be holding it in position both against the noggin also the coupling on that side I need to
tighten it up to the right amount. At this point I need this not to actually be botting out just here
so that's the distance that I wanted to go and I'm going to lock it off against this black knob. So
by unscrewing this now as an assembly I now need to just lock these two against each other. So I'm
going to remove this now and I'm going to put it in a vice so I can hold the black knob and
tighten the locking nut up against it and then this should just give us the perfect pre-loading
to the cartridge. So now I know I've got the right position I've got the right length of thread here
I've messed this all on the machine I just can't quite hold the knob tight enough on its own so I'm
just going to put that into the vice and just hold that without squeezing it too tightly and then I'm
just going to lock this nut up and I'm going to pull that quite tight so that whole assembly stage
really firmly lock together. So now I've tightened this all up in the vice I know that I've got the
length correct here because I've checked it in the machine and I've locked this not against this
handle the knob so let's just check that out when I screw this into the cartridge and it locates I
should see this nut bottom out against the side plate at exactly the same time as the cartridge is
just held absolutely snugly in its right position so I can just tighten that up now I can tighten
up hand tight and that won't come loose the side plate didn't bow out but at the same time when
I hold the cartridge and move it from side to side it's 100% held with no movement at all.