hello welcome to Enots engineering i'm Alan
in today's video i'm making a blank die that has a square hole broached in it
so i can hold a tap in my die holder on the lathe
so let's go to the workshop and see how we do it
now before i go any further i need to set my DRO up
and i can't remember whether i've still have it on diameter or true reading
I want to set it to diameter so i can tell where i am
first switch it off hold the enter key down switch it back
on that enters you into the setup setup program
now with the up and down arrows i can go down until i get radius and diameter
i want to enter that
and it's telling me zero is radius one is diameter
so it's telling me i'm one diameter
press enter come out of that
down quit
so if i zero that move in one millimetre on my slide
it shows two so it's giving me double the reading that i'm actually moving
which is your diameter
measure that
1.1365
so on the DRO i press x
1.1365"
enter
now that sets my tool to that diameter
because i haven't moved my tool since I took the cut
so my tool should be at that diameter within a few thou
1.033
take another few thou off
1.023"
one thou above an inch
that just fits in there
i'm just setting the parting off tool square to the chuck
that's square i'll put it on the side of the chuck
just move my parting off tool to get it square
i fitted the die blank that we made on the lathe
into the die holder and i've held it in the vice
and in the tool holder here the collet i have a piece of 3mm
high speed steel where i've ground a flat
on the front face i don't know whether you can see that on there
and i've also ground a flat on each of the other faces
to make it nearly a square but this is the main face
and what I've done is use a drill to a line up on my original hole
set my DRO to zero in x and y and now i'm using the milling machine as a broach
to try and make a square hole
by using the up and down movements to push the tool through to cut the square
so this is how i'm doing it
turn it around to do the back
use a spanner turn this one around to do the back
check its level square and wind it back to my zero position
lower the broach into the hole
that should go in there that's gone in without touching
now wind it out towards the tool a millimeter
at the same time i'm just going up and down
until I can feel it touch should be about a millimetre
it's just touching there and then I'd go
on my x-axis from the centre out 0.3 millimetres
then back the other way 0.3 millimeters to widen the cut
back to the centre
turn the tool around again 90 degrees
and go towards the tool
about a millimeter
now start cutting
and side to side about 0.3 in each direction
it depends how you've ground your tool the distance you move
you'll have to work it out from the tool
clearly just taking a little bit out now there's a tap i want to go in there
you can see that's not that far off now
it's gone from a round hole to a square hole
okay i think i've finished
so that fits in there
there's the hole
so it fits in there easy
okay here's the tool it's just a 3mm
piece of high speed steel
what i did was grind
a flat on the front the main cutting face
that's as a slope of 2 degrees and then each side i just cleared away
about half a mil of the bar
so that I could get a corner
so that it would go into the edge
on the end of the tap on these is a point but on some you have
a center this fits into the spring-loaded center device to guide it
but i also need the tap wrench on the outside
and i find that when you put the tap wrench on
there's hardly anything coming through to locate in the center
so as i use the same guide bar for dies
by using this die holder on the end
i've made the square hole that fits over the end
then the tap just fits into the hole
it doesn't need to be tight it can be loose like that
so it can line itself up
and as i bring it into the hole
It lines itself up on the hole
and i'm ready for tapping
wind it back
get the tap out put the next tap in
it's ready to go again
that was the idea just to make it a little easier to tap holes
now that's okay for the smaller taps but you'll find in a set of taps you've
probably got five different sizes of square
and different suppliers of taps use different sizes so there's no standard
but also it gets rid of this tap wrench
and you spring and it still aligns it between the
and it's just a just a steel blank with a square hole in
oh well that's it for today hope that was useful
hope you enjoyed it and we'll see you next time on enots engineering
you