Hi students my name is Tom Damico, adjunct faculty for Sinclair College and
today we're going to be starting a lab project 2 - which is on a lathe. It's all
round work that we're doing today so we're going to do a briefing on the
operation of the lathe itself and then we're going to show you a setup that
you'll do every time you go to a different operation or a different
machine, in some cases. And we'll go through that today, so first of all
here's our speed range, right here. These are four different speeds and feed
rates. This is what we set for when we do threading, okay.
We'll show you how to engage and disengage the lead screw and contrary to
milling machines, most of what we do, not 100 percent, probably 90 percent, is power
feed. And we'll go through those quickly, all right. But the first thing
you got to do for setup purposes is no matter what you're doing whether you're
doing turning, threading, grooving, anything, you want to set the center
height of your cutting tool. And this right here is the cutting tool we're
going to use for turning and facing. The other thing, there's a difference between
turning and facing. For example if this were in our collet here and we'll put
that in there. You're
your process sheet will tell you put in a one inch collet, which is what we're
doing, and you just turn it to and with pressure on it torque, pops in like so.
Tighhten it, goes this way you'll see it's
going in like so okay you know I look at my process sheet and it says chuck the
part in the cart with two and a half inches sticking out. So I'm putting this
on like so with about two and a half inches sticking out a little bit more
doesn't hurt.
Go ahead and tighten it like so. And then when you when it
hits, give it a quick jerk like so, and you're good. It won't go anywhere, all
right. But to go back to what we were talking about turning - facing. Facing is
cutting along this surface here. Turning is cutting this way. So first
thing we're going to do we come over here and your center height on this tool
right here at the very point, okay. This adjusts up and down, okay. And when
you do that, to adjust it up and down right here, this has to be loose so that
when we turn this screw nut here one way raises it one way lowers it. So I
don't know where we're at right now it's possible that whoever ran this before
might have been. It's actually on center now, so we don't have to adjust it. So now
we can come back over here.
And then when we do this adjustment, then this is our center height. When
you crank this all the way out, this comes loose. To put it back in, move
that out so it's away from here, pressure on it, and pull back, and it
eventually pop in. Double-check it's locked in and that's when you're going
to use that. At some point in time a lot of people would like to take these
out because that thing is pretty sharp and you can slip a little bit and
ding yourself. So now I'll show you the controls here. Once we start turning
and facing, and don't confuse this with this here. This locks it now you can't turn it.
Up, lock, loose, now you can move it. So you don't want that movement, so you
want to lock it. This here allows you to turn this, okay. So in the facing
position you've got two cutters on here, two inserts, two sides. In order to face
you want this turned in this direction here and you're going to go across this
surface here in power feed. We'll show you how to do that in a minute. Then
when you're going in this direction, this has got to be this way. So that we're
cutting on the side of the insert. These inserts are carbide and
they're replaceable if you chip them. This way goes that way. This way goes
this way. And that seems to be the most confusion with students not realizing
which one is which. So we're going to come over here for that. Away
from your work. We're going to turn on the machine.
Let's say we want to go this way. This control right here. We're in the
turning position right now. It goes in. It's going this way. We want it to go
that way, so we make a change down here. Now
it's going that way you can see that hand wheels this way. Now in order
to go across, what we call facing, this lever has to be out. And it's coming this
way we want to go that way so we need to change it.
There we're going the right direction. This lever here, don't ever fool
with it, because its for threading. A lot of times instead of feeding here, a student
will grab this, and you don't want that, okay. All right so
654 RPM is what we're at and that should be on your process sheet. Yes 654. So let's
say we're going to do facing, alright. We want to turn in this direction. Like
so and we look down at that insert, remember we want to cut on it on the tip
and this surface here. So I like to put it on a positive angle, a little bit this
way.
The digital readout is a little different what we use there but we'll go
through that here in a little bit. So now we're going to touch off
and we're gonna we're going to go ahead. Turn it on right here, come over
here till you just close to touching, now you can see I just took a little chip,
I'm gonna feed over a little bit more.
Now you'll see that move.
All right so now we're going to feed the in and out, and you can see its power
feeding.
Turn it off over here again. Now it is not quite cleaned up, so we'll clean it up. Rub
your finger over the center of that. And if there's a little nubby on there your
center height is not correct. Go back and double-check. But this is real smooth,
So we have good center height. Remember how we set that or at least checked it.
Let's move about five thousandths.
Now you only have to go a little ways past center you don't have to go all the
way across it.