Hello welcome to Enots engineering I'm Alan
this video is part 2 and in this video we finished machining the steel body and
continue making the probe installation block and end cap components for the
electric edge finder at the end of the video I've included some sketches of all
the four parts so you can make your own The probe's designed around a 14
millimeter body and an 8 millimeter diameter battery holder
so let's go in to the workshop and see how we do it
so at the moment I've got 10mm hole in here that goes down to an 8mm on
the other end it's been faced and there's a center chamfer on the end of
the 60 degree chamfer that will accept the center the other end of the bar
we've put an 8mm hole then we've machined it out and tapped a 10mml hole
and there is a chamfer on this end 60 degree that will accept the centre
so it's important for this that the outside is running true to the holes so I'm
going to hold this between centers and then machine the outside down to just
under 14mm put the revolving centre in the tailstock on the headstock
I've put this drive plate with the drive bar centre in this end this centre you
don't need to lubricate because it moves with the head so it's not actually
rubbing on the steel and this centre is a revolving centre with bearings
so that's not rubbing on the steel so I don't need to put any lubrication on the centre's
I will take that out so you can see this is just the driving Dog
which is clamped on so what I want to do is machine most of these stand to 14mm
and then turn it round and then blend the other side into it
I'll go about halfway
that's point 0.621"
0.5515" by the way if you're not sure which way the carrier goes
the machine side always goes to the bar that's pushing it
because that's machined central to the bore
I'll just put a chamfer on this end
I'll put this back in the chuck and al lI need to do is drill a hole through the side
This is a side with the 10mm hole in and what this is is a couple of bearings
linear bearings so that can slide in and out and inside this bar a
bearing each end with a chuck on the end so I can rotate the chuck using a electric drill
that fits in my tall post
Now I've just touched the edge of the drill on
there so now I'll move it in 17mm plus half the diameter
lock up the slide then check it's about 17mm in
Put a small dimple hole on the end
and I need to open it up one side to up to 6mm
this is a LED which should just fit in there
turn this around
and I've just taken a sharp edge off that
there's the three parts we made in brass
this is the body we've got a hole in the side 3mm that side 6mm that side
ten mil hole there that's a threaded 10mm with an 8mml bore down the middle
and the next thing we need to make is the plastic sleeve that goes inside
This is a hard plastic I don't know what what the type of plastic is. It was something I found
so my collets a half inch collet and this is 0.558
that's the plastic that fits on my collet I've change my chuck now for my collet
put that in my ER20 collet 12mm
what we're making is the inside of this tube that's going to fit in there to hold the led
and insulate the electrical connections from the outside
I've turned the part around in the collet and I'm on the other end
Now I just want to face that to get it square
and because I want a flat bottom to this hole I'm using a 5mm end mill
to give me the 5mm hole with a flat bottom
and because I've got my collet in the lathe with the drawbar through and a nut
on the end I can use a spanner on the nut just to turn round the headstock
and I've got my guide in the end just to guide the tap in
I've changed my tap for the bottoming tap
just support in the end with the centre to stop it flexing
so the length needs to be 47mm this is 60
I've machine the length of 47mm
and now I'll set up the tool post spindle to do a cross drill
So that's okay that side this is the LED
and that's drilled halfway through so the LED will fit in halfway
there's finished item a thread in this end to hold the probe
hole through and we've got a 4mm hole straight through
what I want to do is reduce this diameter face centre drill
to suit a ball bearing now the ball bearing that you use on this
this is the actual probe part this is the ball bearing i'm using it's a 3/8 ball bearing
you can use metric bearings it doesn't make any difference
Use the centre drill to form a cone in the end so that bearing will sit in the end
and what you need is the bearing to be bigger than the shaft that your using
when it touches the edge of the part it's the bearing that touches and not the shaft
you see that bearing sits in there so when I solder that bearing onto the end
it'll have plenty of grip so that should be okay
Now it's important that this centre and when I make the thread on this in there all true
okay I put my ER 20 collet back on holding the outside that I've just turned
It looks if it's running out quit a bit
I've got a centre drill for the ball in this end
and a small one in this end so I will put the centres in now turn this down between
centers so I know that that diameter is running true turn around turn this down
between centres so know that this diameters running true
and put the thread on the end
I changed my lathe tool so I can get in closer to the edge
and I'm going to turn the diameter down to 6mm
now that should be around 6mm
0.236" I'm looking for 0.236 that's smack on 6mm
I had to change the carrier to a homemade carrier
because the width of this carrier is too wide for that small length on the diameter
this should just fit in
you can see how close centre drill is to the edge all this is running true between centers
okay now I've put my colletholder back on
I've put a die in my die stock
M6 die go right up to the face
now I'll turn the die around so I can come right up to this face with a thread
now that's touching the face
so by turning the die around you've cut the thread right up to the face
I've set up the indexing fixture in the mill vice I've got a 12mm end mill
and what I want to do is come down just to touch the the face to get my position
that's just touching the part where I want to put the flats on
Turn it round 180 degrees
here's the finished probe and I must admit that I have made two of these one
with the larger diameter than the other so I can have a different sized ball
this is the last part to make the end cap the end cap is just a 10mm thread
by 10mm long on a 13mm diameter that's been knurled with a dome on the end
so it's nothing complicated that's the seven components completed so next time
we'll show the assembly and test it thanks for watching and we'll see you
next time on Enots engineering