welcome to Enots engineering I'm Alan. In today's video we make this new nuts for
the knurling tool now this nut comprises of a hexagon
machined on the one side and a spherical machined on the other side the spherical
goes onto this washer so as you tighten it down it lines up with the washer and
allows the bar to move up or down to self center
and if you tighten this nut up it pulls the two knurling tools in to make the knurl
So let's go into the workshop and see how we do it.
Today Iwant to modify this knurling tool the problem I have,
if I want to put an knurl on the end of the shaft.
when I come in with this tool you can see that this adjusting knob will hit the chuck jaws.
and if you look at the depth of the knurl you can see there that the rod I want to knurl
is only about halfway across the knurling wheel
I've just marked the edge of the knurling wheel with a felt-tip pen.
you can see the mark there so I can only knurl up to that mark
take the adjusting screw off
without that I can then go closer
which brings the knurl nearly up to the jaw it's just the distance of this arm way
so what I intend to do today is make a new adjusting knob
with a smaller diameter
First of all I'll face this off
now I'm drilling the tap size for a 5/16 BSF which I think's 17/64
Now this bar already had a hole in it I've just cleaned that hole out
I'm just using an off cut to make this part that's the 5/16 tap
before I tap it I'll just check that the screw fits that yeah
that's the right thread
now this tap hasn't got a hole in it hasn't got very good dome on the end
I will fit my expanding mandrel that goes in the back of the headstock
how this works as you put the allen key through there as you turn the Allen key
pulls this tapered part in and expands the four segments
I fitted in the headstock the ER20 collet holder which is on a number
3 Morse taper and a drawbar through the headstock
Here is a stud which matches the thread in the part where making
and this plane part will fit in the collet.
so that should lock up on there
Lest see how it runs out that will be ok
this part doesn't do anything
this is the important part that this spherical we put on here runs true to the thread.
This part is going to be machined a bit later anyway
because I need to machine a spherical that matches the nut.
I'll set this tool to the correct position
to adjust the tool slacken off the three cap heads that hold the tool position
then the tool will slide in and out on here
To get the position fit the pin that gives you the zero
move the tool back
now I need it t be one inch from that face to the cutting face
so first thing I do is set the caliper to the width here this 0.157"
so zero it there and now the distance between there and there should be 1"
Tighten them up by hand
recheck it the measurement that's 0.003" over lock the cap heads up
I'm cutting with the bottom of the tip so that means I'll be
starting in the middle and working to the outside the lathe is running in the
normal direction I'm not going to touch the front in the middle to the outside
to form the spherical
I've turned the spherical which I'm happy with and the only problem is now I've got a very sharp edge here on the corner
so I'll just file a radius on there
so the next job is to machine the hexagon on this part so that I can use it with a socket
I fitted a lever type dial indicator in the ER20 collet
and I'm setting my indexing fixture Square to the tool by using the
indicator on the collet spindle.
I've made some modifications to this indexing fixture
On the back I fitted an aluminium angle plate which holds in the tool holder
I've used the existing holes and the locating pin to locate and bolted to the angle plate.
so now I can hold it into the tool holder with the center of the spindle on the center line of the lathe
Now I'm just checking that the indexing spindle is square to the top slide
0.02 of a millimeter out of square which I think is about a 0.001"
This is a setup this is the part we were machining earlier which I've turned round on the threaded stud
so that the concave part is now up against the collet
this is the 15mm diameter we machined
and what I want to do is machine a hexagon on there to fit a socket
I've put the half inch end mill
in the collet on the headstock and I've locked up everything on this fixture.
I've put the cutter up to the face to zero my compound slide
and I'm coming down to touch this face and zero my cross slide
what I will do is take 1/2mm off, index it round to do it in 1/2mm stages
I will index that around
locked the indexing pin in now I'm tightening the spindle up to take the 1/2mm off
I've put a red mark on the bar so I know when I've gone round all the faces
I've just gone around once I'll turn it again
yes that's just starting to go on so what I'll do now is just take off the sharp corners and see it fits
just take this corner off each one
now this fits so
this parts finished we can take that out
you can see now I will just file the edges off this I might just put a chamfer on there we'll swap the Collets over.
This piece replaces this knurled hand nut and the idea is this could come off the
spherical washer fits on there this spherical goes into it so I can get much
closer to the chuck and I can still tighten this with a socket and a wrench
let's see what it looks like on the lathe
this is the position that the nut would be
the old one and you see how close it is to the chuck jaw the new one
I can now move the knurling rollers in another 1/4"
so that this is completely clear of the chuck jaws, now if anything touches it's the actual side of the knurling holder
I can knurl closer to the chuck so I don't have to have the work coming further out.
normally I'd have done it about there so it's held a bit more firmly in the chuck rather than coming out this far
I can use that little socket which is a quarter inch ratchet to fit that
this is the the spherical we made to fit that washer
so it lines up
Well that's it for today I hope that was useful and hope to see you next time on Enots engineering