hello welcome to Enots engineering.
Im Alan
in this video which is part two we'll be cutting the screw thread on the blanks
that we made in part one the screw thread is a left hand thread Imperial
and the lathe is metric so I'll show you how to set up the lathe to cut Imperial
threads and we'll finish off these chuck jaw screws so I'm gonna get the
four jaw chuck working again as you see this one it's just broken away
for cutting 8 teeth per inch on a 3 millimeter leadscrew I need 3 gears the
36 tooth gear which is that one and this hold remained I've got the actual
numbers on them so I can see what's missing and a 32 tooth gear which is this
one they are the standard gears to convert from metric to imperial I also
need this one which is a 135 tooth gear with a hundred and twenty seventh tooth gear
combined this is a set up for the gear wheels we've got a 36 on there a 32 on
the lead screw and this is a conversion gear.
twenty nine and a half degree angle flattop because it's a form tool you
don't put a a rake on the top otherwise you'll lose the form shape I'm just
sitting at all that sent to height First of all I will set my clock to zero
jack the tool up
till it just starts to move and I know that's it sent to height so I'll just
check that my tools square by placing a square on the job and bringing it into
the tool just checking that its square with the job
just touch the tool onto the job and zeroed my cross slide so I know we can
start there I've measured on this one the diameter on the outside which have
already reproduced on this and I've measured the distance between the bottom
of the threads I've calculated that I need to go 0.065" deep to form that thread.
And because it's the left-hand thread we start cutting this end and go across I need to
slow the speed down and engage the thread cutting I've marked up the the
part with blue so I consume it it's cut you know I'm going to take a trial cut just
to check that the number of teeth match up with the part
yeah at matches so now I've engaged the lead screw a can't disengage it.
so I have to back the tool off revers the lathe
j ust check that it is ok that's the jaw as you can see that fits in the thread
not quite deep enough yet. I've got another 0.2mm
now that should be down to
depth so right on the jaw
if I compare that speed it up emery over the top of
that to get a nice smooth finish because it's thrown up a bear on all the edges
there turn it round do exactly the same on the other end
okay I've turned it around before I start cutting the thread just checking
the run out within a couple of thou which is okay for that. Start cutting the next thread
The next job is to part this off and then face the end
I think I will saw that little bit off
I got some more to come off that
2.133" that's finished
2.133 so I'll just put a chamfer on that one
we've got four chuck jaw screws there's the original al with hexagons on
the end and I can reassemble the Chuck
so check in there that it will fit the
Chuck It should just slide in there which it does next job is to put the pin back in
the back these pins here hold the Chuck jaw central
Put the screw back in that hole
Two jaws that's an original that's an original that's the one we've just made
and that's the one I made before so now just put it back on the plate and its ready to
there we go one four jaw Chuck repaired ready for
action
well I hope you enjoyed it. I hope to see you next time on Enots engineering