4 jaw chuck repair part 2


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

Comments 11

  • I like it. Good video. Will keep it in mind if/when I break a screw.

  • Great video. When you redo the jaw screws should you also regained the teeth again?

  • Nice one Alan, thanks for bringing us a unique and useful project, part two was well worth the wait, great video

  • what grade of material did you use for the screws? super video's

  • Wouldn't it have been easier to buy a length of suitable screw stock (of a suitably hard grade) and make the screws out of that?

  • Excellent video! I have to repair my 4 jaw chuck as well, except the screw didn't fail, the keeper that holds the screw in position failed. Mine are pressed in, they do not have a screw to hold them in place. I'm not sure if you'll know the answer but what material do you recommend I make the keeper from? Should it be heat treated as well?

  • ces le genre de pièce qu'il faut choisir dans un acier assez dure et le tremper , et mettez la pointe tournante en bout ces trop flexible .

  • great work!

  • Very nice. I really enjoyed watching you make those screw adjusters.

  • The discovery of this video was perfect timing. I need to replace an operating screw for my Burnerd model 36, 5-inch four jaw chuck. I actually managed to find a replacement unit at $194.27 plus GST and freight – ouch! Fortunately the three jaw is fine.

  • Beautiful job Alan loved every minute

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