Boxford lathe Changing the drive unit bearings.
Boxford lathe Changing the drive unit bearings.

Hello welcome to Enots engineering I’m
Alan in today’s video I’ll be replacing the bearings on the bottom and the top
pulley spindles for the lathe drive system this is one of the bearings I’ll
show you how to replace them in this video. So this is the bottom of the boxford
of the lathe. Where motor is and I’ve got a problem with something rattling I can’t
find out what it is. The first thing obviously is turn the
power off disconnect this tensioning mechanism. A nut and bolt on the side and a nut and bolt on that side and the motor units at the bottom should come out a lock nut on this side slacken off the bolt. On this the bolts or underneath the shaft so I can’t get the socket on it. just the motor on its own. Get this
cleaned down now can get at it. connector box release the sponge from behind it. I can see how they’ve identified it. All the wires are white and pink so basically we’ve got a white and a pink and a white and pink on the side. On the side
they’ve just stuck some red tape on to denote that these two go together. Undo it from the cable side That should pull the wires through and this I’ve clean the motor down. I just sprayed it with some degreaser and wiped it
over this is a electric motor it’s a Compton Parkinson motor AC motor
220 volts to 240 single-phase 0.75 horsepower and I think it does 1425 revs
per minute looking at it I can’t say anything wrong with it works ok so I’m
going to do on this is clean it up a bit take the cover off and check the bearings
I’ve got grease in but as you can see from that it’s revolving freely there’s
nothing catching there’s no noise so I’ll just checked that its got grease in. And also I’ll check that this pulleys tight on that that’s tight. that’s tight doesn’t need to be tightened and I can’t feel any play in it I’m quite happy with that.
motor. Just turn it round and take the back cover off here and see what the what we have. The grease look all right as well. Just take that out and repack it. Re packed the grease put the cover back on. So that ends OK. rotating freely so don’t think there anything wrong with the motor. So I’ll put the motor back on the floor and I’ll get the carriage that it fits
on. The electric motor drives the
belt which turns this side and this is a five different speeds you can they have
on this side so it’s another belt that goes on here it goes up to a spindle
that goes across the top. The only thing I’ve noticed is that this pulley on this end it’s got play in this pulley on this
end. Let me take the shaft off the base plate now I’ve notice there is grease that’s gone hard on the face here clear the grease off here clean this off and bolt that back
to the motor. I’ve taken off the pulley on the motor side taken the woodruff
key out of the shaft. Which goes in there I’ve cleaned all this down spin the bearing
it sounds as if there’s no grease in the bearing. I think what’s happened is the
grease has escaped somehow that sounds like new bearings need on that. You
can hear its a bit rought. I’ve drilled the grub screw out on this end because trying to undo it it has bending the allen key for some reason it was jammed in. Okay lets bring
you up to date with what’s happened. I’ve started to reassemble the motor and the holders I’ve bolted the frame to the top of the motor cleaned it down the bearings have arrived I’vel clean the original holders these are KSM bearings I thought they’d be some sort
of cheap replacement that actually made in Japan so the quality should be okay Lets check that they are the same. The first job is just tap them into the housings okay I’ll press the first bearing into
the housing the way I did that was. You put the bearing into the housing square Put it into the Vice with jaw
protectors and push it in till it’s come to the front and using a big socket which is just smaller than the OD of the bearing use that to hold it between the vise and
push it in all the way home. Just file the flat on this end a bit further along the grub screw was going on to the edge of the flat rather than on the flat itself. you can see now I’ve just taking the flat back about a quarter of an inch that’s where that hole was
that’s where the pulley is going to clamp on so I can use a hole for the
grub screw to locating and I know that pulleys in exactly the same position as
it was before. Now found piece a tube it just fits over the bearing the next I,ve done is put the
Woodruff key and I did that just by putting some voice to your protectors on
and just using the voice to squash it back into the slot. So all that remains
now is to put pulley on I’m just tapping the pulley on I’ve got a block of wood
on the end of a pulley holding the shaft in the voice with some jaw
protectors and just tap we’ve pushed the pulley on until it lines up see in the
bottom of the hole where the drill went through just spotted the flat I’ve cleaned
out the area wood down the oil and grease off the sides clean the floor so
it’s ready to go back in Now while I’ve got this empty I’ve
decided to replace the bearings in the top shaft all I need to do here is undo
the four bolts for the bearing holders slide the belts off and I can take the
bearing holders off the end of the shaft replace the bearings in the same way as
the did on the main shaft. The bearings have arrived for the top shaf t. Part number R 1 2 Z Z KSM Japanese bearings again. I’ve just got to press
these into the holders place them onto the shaft and bolt the shaft back onto
the machine I’ve also got a new drive belt because I thought the other belt was a
bit stiff should be enough adjustment on the length to take up an inch or two on
the diameter but that was the nearest size I could get to the existing one
that I had. I’ve use d the socket again which goes on the outside of the bearing
to press it home now I’ve turned it around in the vice. I’ve got some lead jaw
protectors on the vice to stop it damaging the shaft. so both bearings are up against the face that’s ready now to go back into the
lathe. When putting the shaft back in The first job is to put the main drive
belt from the headstock on to the center pulley and put the speed change belt on
to the pulley before you bolt the spindle down. if you slide the spindle
in under the bracket that just puts a little bit of tension on the center belt
so I’ll need to do now is put the four nuts and bolts back in and then align
the belt by pushing it backwards or forwards to get it back in similar
position to it was before. I put the bolts in loosely you can’t move it left
or right so that lines up with the brackets but you can push it backwards
and forwards and all I’m doing is bringing it forward on each bearing housing so I know that it’s square and also checked that the belt, your head
stock belt is clear where it goes through the lathe base and there’s a slot so you
want to make sure that the belts not running up against the the lathe cabinet
that’s clear so now all I’ve gotta do is tighten the four bolts up and put the
pulley on the drive so once you’ve put put your assembly back together just
recheck the belts are still in line now all override these safety switch and see
how it runs let’s change it up full speed this belts not worn in yet
drop it down to the Midway so you’ve hardly got any tension on there at all. Well hope you found that interesting and
if you did why not give me the thumbs up or subscribe and we’ll
see you next time on a Enots engineering

6 thoughts on “Boxford lathe Changing the drive unit bearings.”

  1. The Funeral Director 1965 says:

    Sweet, I think I could do with a new lathe belt, when I'm at full speed I can hear it trying to speed up, I don't live far from MSC I might see if they've got one and gear meself up to changing it,  thanks for the video

  2. Billy T says:

    good repair, you were wise to change all 4.

  3. Mark Geraghty says:

    You do work quick Alan, those fingers move like lightning

  4. enots engineering says:

    Hi Someone asked if I had a wiring diagram for the Boxford Lathe I've lost the comment sorry I don't have one but you could try they do have Boxford details.

  5. John Edwards says:

    Hi Alan Just wondered if you are single Phase or 3 phase and if single what the HP is?

  6. John Edwards says:

    Sorry Alan i paused the video to soon , I now have the info….Thanks for the video,s They are most interesting and a great help

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