hello welcome to Enots engineering i'm Alan
in today's video we continue making the rotary brooch from hemingway
and we start by making the spindle
now last week i made the body and it was due to gone to the milling machine
but the instructions say to make the spindle next before you do the milling
so you can take some sizes off the body and make the spindles a suit
so let's go into the workshop and see how we do it
let's have a recap of where we got to at the moment
in the first video we made the locking ring
in the second video we made the shank and in the last video we started to make the body
now i was going to continue with this in this video
but looking at the instructions they suggest that we now start to make the spindle
as we need to calculate some lengths from the body
this is a spindle for the rotary broach and it's says to hold this further out in the chuck
so you can turn from this way in and
from the chuck side out to form a centre piece
now i've got a problem is that it's only holding on the very end of this bar
i'm not too happy about turning
from the chuck outwards because i haven't got much room to get the tool in
so what i will do is drill it and centre it and machine the outside between centres
and then i know that all the outside is running true
so that's the one end let's turn it around now
and just centre drill this end
each end I've a centre drill hole centre to line up on
so now i'll change the chuck for the centre
when i turn this bar around in the chuck and centre drilled it
i found that the. hole the four millimetre hole was running out
so what i've done is just drill five millimetres to true it up
and then i've re-centered on the end so that's why there's an extra bore in there
this part will be machined out to 8mm i think it is
so that won't affect it
so what i have is a center that's running through to that hole
and the center that's running through to that hole
i've set up centre in the headstock and a revolving center in the tailstock
this is the driving pin here and that fits into this
slot so that goes into there and that holds it on the end
now the beauty of doing it this way is I can take this out
as many times as i like to check sizes to check fits
and it will still run true between centers
and then when i come to do the back end instead of struggling to get in between
the chuck with the tool and the face that i'm doing
all i do is turn it around put the driving dog on this side
turn the whole job around
put it back between centers and i can machine this side as normal
now i was asked about these where did i get this driving dog from
this one is in a set
and the set goes from that size up to this size about inch and a half
and they were made really for a grinding machine
they came with a grinding machine i used to use
and when the company closed down the machines were just being scrapped off
and all the parts that went with it were been thrown in the scrap bin
so I said can i have that and they said yes so i had a set of carriers
which i use on the lathe
let's put this between centers i don't need to oil these centers
because they're not moving
this one stays with the part as the part rotates the center is fixed
with the part this one is a rotating center
so there's no friction on the inside of the center
this is called the live center because it's actually moving
if you put a dead center in
that is a centre like that which is just a morse taper with a centre on
if you put a dead centre in
then you'd have to lubricate the end here
to make sure it doesn't overheat
Now the whole part is only 30mm long which is nearly there
i'm just watching that my driving dog's not gonna
hit my tool post
i've changed my tool to a high speed steel tool
mainly because the tool is getting too wide to go in the gap again
so with this tool i can get right down to the face
that will it's a tight tight fit but it will slide up there
so i'm not going to take any more off on the lathe i can always
use some emery cloth if i need to okay i've turned it round in the lathe
put another driving dog
on this different size because it's only 10 mil diameter now
and i need to turn this down
you can see here i had a problem with the turning
i couldn't figure it out at first the travis was on and
the it was going along that way and then all of a sudden it started to
go into the job as well i thought what the what what's going on
i've never had both well you can't have both travis
working at the same time and what it was put the tool post here
there's the plunger that holds the
tool in and what happened it got caught behind the
revolving center and then started to turn the tool post as it was
coming along because this wasn't moving this was
holding it still and cut into the job well luckily this
is all scrap here anyway it's only
about 15 mil i need from here to the end so i'm going to cut this off
but i didn't want to do it yet because obviously
i'm still working and luckily it's still held on
if it got another half a mil deeper i think it just parted it off
so i've never had that happen before there's something to
bear in mind in the future if the plunger here
is coming along and catches the back of the
revolving center one way of preventing it is just
turn the lever in so it's pulled the plunger in anyway i think
that's finished on that side the bearing should fit on there
okay so I will just try the bearing
you can see it goes on to about there and the difference in size between there
and the end is about half a thou so i'm going to
leave it at that as this this bearing goes up to that face
i've just faced the width of this off
so to calculate the width of the spindle
in the middle we need to put the thrust bearing
in the bottom of the body and measure from the top of the thrust bearing
to the top of the body then put the radial bearing in
and measure from the top of the radial bearing to the top of the body
then take the thickness of the bearing add it to the height that we've just
measured and take that away from the first
reading from the thrust bearing to the top and it
should give you the width of this
and that's what we have to machine on the middle of the spindle
which is that calculated width less a couple of thou
okay that's as far as i can go between centres just finish the thickness of this
i'm using a piece of silver steel that came with the kit as a gauge
all i've done is ground a slight bevel on the edge because it was sharp
that's that
so this part's now finished except for a hole going through the
side and cutting off to length
and here we have the completed spindle with the m4 grub screw fitted
oh well that's it for today hope that was interesting hope you enjoyed it
and we'll see you next time on
Enots engineering