hello I'm Alan and welcome to Enots engineering in this video we're making
two components for the radius cutter the first is a new setting piece with the
flat in the middle so the tool tip can come straight down to the middle for
setting and the second is an offset tip holder which will bring the tip closer
to the setting piece so let's go to the workshop see how we make them.
This is a radius cutter and that's my setting pin if you've watched the other video
you'll know that that is a six mile radius so that pin is 12 mil and it fits
in an 8 mil dowel in the center of the radius cutter so what I need to do to
get smaller than a 6 mil radius make it so that I can mill flat on here halfway
down the diameter in the center line and be able to put the tip of the tool to
that flat so can go down to 0 and then with the flat on I could use gauge
blocks or vernier to give me a measurement from the actual center line
to the tip
just over 0.315" (8MM) I'm setting the parting off tool square
using the square up against the part of just made.
I've selected the tool holder with a V in the base.
I've mounted the bar in the tool holder next job is to clock this up true
to the holder now I've put a milling cutter in there a mill the end of the bar
it's about 0.0003"over 2 inches
I,ve put some steel in the four jaw chuck I've changed the dial indicators the one that
will give me at least a 3mm reading.
zero there 10 20 30 40 10 20 30
3mill is 120 that's about right so what I'm going to do now is slacking off this
jaw at the back and push this tighten up this jaw so the clock is back to the
original zero.
so tighten this back up till it comes to zero.
that's near enough this is in tenths of a thou so it's near enough
just make sure the others lare locked
what I'll do is just turn a small diameter to see how it looks
it's just trued up that 0.496"
Thats to steady that.
Now let's put this back on center.
I need to push it now the opposite way to what I did before.
So with the big diameter running true and this diameter at its
farthest out I'm now going to push this diameter further out by another 2mm
I've already put two mil on the clock undo this and push this over to try to
bring it back up to zero.
just moved my centre in to see where the center will be.I've got some offset about 4 mm
my next job is to part this off
This is a three mil tap
let's just put the flat bottom hole there just to give the milling cutter less work.
When I did this in the past I used a three jaw chuck but because I'm
on a four jaw chuck I haven't got any reference points so I'm having to use it
chuck jaw and a thirty degree offset so that will give me 90 120 degree turn
to get the three points on the triangle so that's 120 120 120 which is your 360
what I'm doing is putting spirit level which is set at 30 on to the chuck jaw
and here see the bubble in the level which is level on that chuck jaw
I've got this in back gear so the chuck is less likely to move, so I'm ready to cut the second flat.
Now we went to turn it around 90 degrees
Get this lined up on the next chuck jaw
Take this out and have a look.
Let me try and explain while doing with the chuck jaws to get the triangle.
These represent the chuck jaws this is the job in the chuck
The first thing I did was set this jaw to zero and cut just below the
centre line a flat then the next thing you do is rotate it to the next jaw
which is 90 degrees plus your 30 to get your 120 so your bring this to there.
With the spirit level on the jaw, then you cut your next flat which would be there.
Now because this jaw is already 30 off to get back to the next jaw its 60
Plus another 60 to get your third flat. which produces the triangle to hold the tungsten tip.
to get the size bigger for the triangle you
lower the cutting tool in the tool post so that it drops further down and takes
more off the flats when you just repeat the process again going round until
you've cut the flats big enough to put the tip in.
I'm doing at the moment it's just milling off the edges of this part that
sticks out so that the tip of the cutter can get right in close.
that's the finished tool holder that flat is the centre of the radius cutter and then
this can move in up to the centre and you just put slip gauges (gauge blocks)
or feeler gauges in there to set this at the size you need.
oh well that's it for today hope
this was useful hope to see you next time on a Enots engineering