Headstock Bearing adjustment and back gear.
Headstock Bearing adjustment and back gear.


Hello welcome to a lot centenary I’m Alan
in today’s video we’ll be checking the bearing play in the headstock and
showing how to adjust the bearing play and we’ll also have a look at the back
gear on the headstock and how it works so let’s go into the workshop. First of all
we remove the Chuck always put the board on the bed so that if you do drop the
Chuck at least it’s not going to damage the bed
here is the locking pin select the locking pin the mark comes up to the top I use
the Chuck key but you it’s possible if it’s tight you might break your Chuck
key you can always use something in the Chuck jaws or across the chuck jaws it
shouldn’t be that tight obviously some Chuck’s have a locking nut at the back
that you undo. The Chuck’s on the taper. This is a screw Chuck so what I’ll
do is I’ll take this cover off here just to show the bearings are behind this
cover at the same time I’ll clean it out there are three cap heads that hold the
cover on You see there’s no grease seal as such there’s just these three grooves and the idea is if the grease gets into
there it slowly moves along and the spindle keeps it in position. I will clean
the face make sure there’s no swarf or anything
on this face to get into the bearings. I did wipe it down before I took the cover off. See if I can show you the bearings you can see the bearing there I will see if I can turn that So you have one bearing on this side and
the other bearing is at the back of the headstock I’ll just drop this on the
floor and my luck it landed with the grease down so this was covered in swarf
and bits I’ve had to clean it down I’ll put these back on tighten these
screws up it doesn’t need to be too tight this is
the grease nipple you put too much grease in there it’ll come out of here
and also come out inside I’ll take the cover off tighten the four screws out so
you usually get oil on the inside then you can see the main drive belt this is
obviously the back gear undo this. That’s engaged into back gear and this gear hear you see aligned with that one and on this side you see the gears here
as I move the lever this gear comes forward and engages as you
disconnect and put it in back gear. there’s four pins on here that come out
of this part this shaft moves with the gears on so the drive belt now
drives this gear at the back through these gear that gear back onto that gear
to drive the head and when you’re not in back gear the drive belt drives this
which drives this gear and turns the chuck you see down here grease it’s
coming at the back of the second bearing and this just fills up with grease some
I’ve just taken off so you don’t need a lot of grease because when you grease
the bearings the excess grease will come out on the inside here and fill this
gear. It gets on your belt and your belt starts to slip so eventually this will
get full of grease and just throws it around in here this label tells you when
you’re using back gear oil daily what you do is you put your oil can through there
and it goes into this oil nipple there and puts oil inside of this and if you
put too much oil in it just throws it all over the place so just say when
using back gear so I don’t oil that unless I’m using the back gear. The rear of the
lathe in where the gearbox is you’ve got these three cap heads hold an
aluminium plate in which covers the bearing this is a screw thread here and
this is how you adjust your bearings this part here is
nut to do it properly you need a C spanner with the pins in that will fit in
these holes If I turn it around you’ll also see holes
all the way around but there are also two grub screws you need to slacken
these grub screws off before you try to move the nut. let’s check if the
bearing needs adjusting I’ve clean the spindle out let’s put this morse taper in Ive put a dial indicator in the tool holder what I’m doing is just pulling on the
end of this bar to see what play I’ve in there it’s about a thou. if you move your
dial indicator out to this end the play will be more. And if you move and if you move your indicator down towards the headstock you’ll see that the reading is reduced.
So by using a test piece like this you are actually magnifying the reading this is
the true reading on the end here. Which is about a tenth. I’m happy with that because it’s not giving me any problems. so to adjust the end play, slacking off the
grub screws there on the outside of these nut. If you’re lucky you can use
the allen key once you’re slacking the grub screw to turn the nut but if it’s
really tight you’d need to get a C spanner to put into this hole and turn the nut. the C spanner. You don’t need to tighten
it tight so what you’re doing is crushing your
bearings together slacken the grub screws off turn the nut a fraction and
then go back and check your play on the dial indicator once you’ve reduced it tighten the grub screw back up again put a bit of grease
in before you start it up. I adjusted this six months ago it’s still less than
a tenth on the end there. Let me try and explain how the bearings work. This is the chuck side this is a screw thread for the chuck here you’ve got the
diameter that your Chuck locates on off the backplate.
that continues down this is a roller bearing, this is the bearing shell and
this is recessed into the casting of the headstock so it goes in this way and the
back of the casting comes at the back of it so it won’t go any further on the
other end the other bearing goes the opposite way the recess is this way the
shell is at the back and the bearing goes in here then the nut that you
adjust is on the back of that so as you tighten his nuts up its compresses the
bearings between the headstock because this bearing car go that way
because the larger diameter the only way can go is this way this bearing can’t
come out because they’re nuts on the back so as you tighten that nut up it
compresses two bearings together into the housings or into the bearing shells
and reduces the end play. So when you’ve got end play the distance
between the two shells is too big and the the bearings are doing that. As you
compress the bearings it tightens up. if you over adjust it obviously you’re then
going to put more wear on the bearings more pressure which will produce more
heat so you have to get this back play just right and it’s better to be on the
loose side then on the over-tighten side just hold the bar pull it in and out. You
can see that’s quite a bit of force on there. That’s it for today I hope that was useful and if you enjoyed it why not subscribed and we’ll see you next time on Enots engineering

11 thoughts on “Headstock Bearing adjustment and back gear.”

  1. Pete Sreges says:

    Happy Birthday. Congrats with your channel.

  2. david sanderson says:

    good video Alan have you seen the boxford method for checking bearing adjustment congrats on your 1st year 
    all the best Dave

  3. The Funeral Director 1965 says:

    Happy Birthday enots engineering, thanks for putting your foot in the water to make these really useful videos

  4. Anthony says:

    Congratulations on a year. Job well done. I've watched most all of your videos , I really like the ones on the ball turning attachment.

  5. lookcreations says:

    Just found your channel & Sub'd looking forward to going through your videos. I love to use my Boxford AUD III and am looking into getting it back into better running condition. All the best Mat

  6. John Edwards says:

    Very Useful, Thanks Alan

  7. Gareth Burrows says:

    Thanks for this, need to adjust mine soon, easy after watching this 👍

  8. ZENOIST2 says:

    It looks like a good lathe and well worth getting up and running,
    A problem might be a lack of available spare parts with a Boxford.
    I went for a myford ml7 which has easily available spare parts despite it being old.

  9. Jeremy Travis says:

    I had not got round to looking at the bearings in my Boxford. Something I should do before I put it into commission.

  10. Frank Sloan says:

    Hi Alan I've just bought a cub are there any strip down videos on YouTube that you know of I'm new to Boxfords.

  11. James Davies says:

    Hi, can you tell me what taper the spindle has on the ID? is it a MT or something different. Thanks, Jim

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