Hello welcome to Enots engineering I'm Alan
in today's video I'm revisiting the tool setting gauge
that I made about three years ago
mainly because I wanted to see whether it still was accurate
in that the height I've got this set to was still the centre line of the headstock
and I'll say the centre line at the headstock because
the headstock on most lathes doesn't move when you turn something in the chuck
it's the headstock that you need to set your tool to rather than the tailstock
which slides up and down and over the years will wear
the tailstock base will wear and it will drop down
so you'd need to pack up a tail stock to put it back on centre
but by using this tool setting gauge it works off the centre line of the machine
I'll also be showing you how to use slip gauges or gauge blocks
how you build up a block height for a certain size
so that's going to the workshop and see how we do it
today I'm checking my tool height setting gauge
too see how much the lathe has worn over the last three years
and whether it's still reading correctly
and to do that I need to put a dowel in the headstock
so the first thing I'm going to do is clean out the number 3 Morse taper
and fit a collet
in the end of the collet I'm fitting a dowel peg
this dowel is 0.3125" which is 5/16
tighten it up It doesn't need to be too tight I'm only using it to measure
so with the 5/16 dowel in we know where the centerline of the dowel is to the bottom
what I want to do is check we're the face of my compound slide is to the centre line
before to do that I'll show you the tool I use for setting my tool height
the part is made from 3 pieces
a steel cylinder that's recessed at the bottom flat on the top
a brass screw that goes through the side
and just a flat disc on this side with a shape on here
so that when it fits on the dial indicator
it locates on the body and clears the bezel
this goes then on the top place it down onto a flat surface
lock the dial indicator so it just comes through the bottom
and then you can zero it
now what I'm trying to work out now is the height from the top of the compound slide
to that lip underneath and whether that lip is on the centre line of the lathe
and the way I'm going to do that is use some
slip gauges or Joey blocks or gage blocks depends what you want to call them
when I was in the tool room we used to call them slip gages
some of the older tool room people called them Joey blocks
because they were made by Johansson
I think that was the first person who made the set of slip gages or gauge blocks
now that tend to be called gage blocks
this is one of the gage blocks this is a 1" one
what I want to do is just check
and that slides under there it just lifts the dial indicator up o.002"
so that's not far out
and what I want to know is what is the distance
from the face the underside of that dowel
The dowel size is 0.3125" half of that is 0.15625"
so I know it's 0.15625" from the centre line of the dowel to the underneath
which if the height was an 1" would leave me 0.84375"
now have built up the gage blocks to 0.8437"
and that is too big to fit under
so now what I'll do is just go down 0.002"
a bit lower
and that's 0.836"
so I've put slip gages under the dowel and it came to 0.836"
plus the 1.5625" forget the five
that becomes 0.9922"
and my high gauge was set to 0.9942"
so I was 0.002" out
so the distance in slip gauges and half the dowel is 0.9922"
so now I know the size from the center to the top
so what I need on my centre finder
If I make up 0.992" in slip gauges
should just slide on to that centre finder
this is the set of gauge blocks I have these are a workshop grade block
well I know you can get inspection grade they are obviously more accurate
so these are just general workshop grade
and international inch at 68 degrees Fahrenheit
just means when the temperature of 68 degrees Fahrenheit they will be correct within their manufacturing limits
I don't have a calibration certificate for these
I got these for about £20 a couple of years ago
these are made by Coventry Gage and tool company
and you get blocks going up in different sizes
I'll just point out these what these two blocks on the end there are protective slips
that's where we get the name slip gauges these are protected slips
they're both 0.1"and the idea of this is
if you're using the gage blocks continuously set at a size
you could put one of these each side of the build up
so that the wear happens on these blocks are not on the the set
I want to build up 0.9942" these go up in thous
from 0.101" to 0.19"
these go up in tenths and then these are the odd block sizes between
so as I said before you start with the lowest size which would be the 0.1002"
which is this one
there we go 0.1002" so that's the first block
so now I have the .1002" the next one is 0.104"
there's my 0.104" block
0.104 so I add the two together I've got 0.2042"
now I want point 0.190"
which is this block on the end see there 0.190"
so I add that to the pack now I've built that pack up with three gauges and it comes to
0.3942" so all I need to do now is that the final block to make up the 0.9"
which would be 0.600" this is already 0.3
So 0.600"
So that stack now becomes 0.9942"which is what I need
now I've set these slip gauges up and what I have there is 0.9942"
and we said that the centreline distance was 0.9922"
So I'm on 0.002" higher on my tool setting gauge
when that finger moves I know that I'm 0.002" above the centre height
now can take 0.002" off the bottom of that so I know it's right
I'v just put an extra thou on this block set
so now when I push you under
you can see the dial indicator moves 0.001"
so that's telling me if that was my tool height
I would be 0.001" above plus the other two thou that it's already out
so that's 0.003"above centreline
I won't bother with the 0.002"
I know that if I can get my tool setting within 0.002" that's ample
especially when you're doing forming form tools and thread cutting
so what I've done if I just recap
we've put a dowel in the centre to give me the centreline of the headstock
and then half the dowel that's 0.3125" the dowel
half of that is 0.15625'
and then originally I thought it was an inch from the compound slide to the centre line but it's about 0.008" under
over the years as these slides are wearing the whole thing is slowly dropping down
so that gap will get bigger if anything
so I'll leave my setting gauges is
I will just show you how it works
one thing I'll point out about the slip gauges or gauge blocks
always start with the smaller size and add the blocks up
so you get the correct size
to check the tool height all I do put the tool in the holder swing it around
that should slide under there that height is too high
just tighten the tool holder up
so all I do is lower the tool down untill the gauge drops over the top
and then lift the tool up untill it moves
and lock it in position that's all is on center line
turn it around
and I can do that with my boring bars or anything that I need to put on centre line
just bring it back over
do again I undo the adjusting clamp
lower the tool then just nip the clamp so I can hook raise the tool
make sure it's just on the edge of the lip as that dial indicator moves
tighten the tool
a couple of thou over and just turn it around
If i put the centre in the tailstock
I was trying to set that to this centre
because it's not got a sharp point on the centre it's difficult to tell where the center is
bring that over
now on that it looks above
so if I set it to the centre
I would say it's probably their
the headstock doesn't move so this is the centre line of the headstock
the tailstock you're pushing it backwards and forwards
this has probably dropped over the years because obviously you've got wear
on the bottom of the slides for the tail stock
now this has been set with the
centre
as you can see its leaving a small pip on the end of the bar
so now I'll reset the tool
Now I'm going to set it to the tool gauge which is there
no pip on the brass
always set you dial indicator to zero when you place it on the compound slide
you can set your boring bar you're parting off tools
and your lathe tools with that
well that's it for today thanks for watching and we'll see you next time
on Enots engineering