Hello welcome to Enots engineering I'm Alan
Today I'm making a new tool hight adjusting screw for the tool holder.
The tool holder was a copy of the original Boxford one.
We put a diamond knurl on the top on this diamond knurl I haven't gone full depth.
so I haven't formed the Diamonds fully because when
the diamonds are fully formed they create a sharp edge and it's not very comfortable to hold.
So let's go into the workshop and see how we do it.
It sticks out 4 or 5 inches from the chuck so I expect a bit of vibration.
Make sure it's running true in the chuck.
I've just got my tool holder with a dial indicator fixed to a bar.
which I made in a previous video.
This drops into the post and locks
You can bring it in on the part rotate the part by hand.
Select the highest jaw which is this one
slacken the opposite side
tighten this side up and try and half the error.
just tighten all the jaws
That's running within a 0.001" I expect you to be probably worse down this end.
What I am going to make today is the height adjustment for the tool post.
This one is a far eastern copy of this and I found that the diameter on this is about 1.5mm smaller
Which means when it goes into this slot when you lock the tool up
Its just touching on the edge I want it to go further in so it's got a positive lock.
This one being a copy as a metric thread the original ones have a BSW thread.
The copy is a little taller which doesn't make any difference really its just a bit easy to a adjust if you haven't got the screws in the way.
I want to make a copy of that with the metric thread for my metric tool holder.
With a bigger diameter, the thread on here is an 8 x 1.25mm pitch.
and at the same time as I make the new one.
I want to mark a line on the top so I can see where it sets
I've put a 6.5mm drill in the tailstock and I need to go in 25mm deep.
Now I've changed my drill for a 17/64" drill which is nearly 6.7mm
So with this tap I will need to go past the threads at least to get to the full depth.
I fitted my spring-loaded tap guide in the tailstock and I fitted on the rear of the
headstock the handle so I can turn the headstock by hand.
I've just changed the tap for the
bottoming tap so I know the thread will go right to the end
And before I go any deeper I want to prepare this end to put the knurl,
because if I go down to 12mm that only leaves 4mm (2mm) on each side of the hol.
to hold that and I know when I put the knurl on it's going to put a lot of pressure on this side of the job.
so I will put the knurl on next
I will just put a chamfer on the inside.
on the original screws the knurl is a straight cut.
and on the Chinese it's a diamond knurl.
I could do either this knurling tool which
was made out of an old tungsten carbide braze bit
and all I did was cut a slot in it put a 6mm cap head through.
so it would rotate, with a straight knurl you only need one knurling tool with a diamond knurl.
you have two tools one puts the cut one way the other puts it the other way.
when I say cut you're actually compressing the material into the shape of the knurl
The first thing I always do is make sure you've no bits of material left in
from the previous one give these a wire brush to get all the bits out
otherwise all you'll be doing is crushing bits of swarf into the job.
I'll just use a little wire brush give the knurling rollers a brush.
This tool is adjustable so it will adjust if you're above or below centre
you also need to put some oil on these because that's it knurling it needs lubrication on the rollers inside.
because it hasn't got this type of knurling with the wheels there.
where these come in as you tighten it up.
This dissipates the force each side to each wheel so you're actually clamping the part between the two wheels.
With this one as you're putting the on as you're feeding in to the part,
you're pushing the part away so to help the lathe what I've done is put my revolving centre in the tail stock.
Lock the revolving centre up on that to help dissipate the force between the tailstock and the headstock bearing.
Just check that it's square if the compound slides fully forward in this direction.
you're putting a lot of leverage on the compound slide so the closer you get the tool
to the center of the compound slide the less leverage you're putting on the clamping nuts.
that hold the compound slide.
I'll just put that on get it in the center.
I've just selected the slowest speed which is 210 rpm.
Make sure that the center is engaged
I'm just going to feed this in
Now I can hear the part rubbing and you can see now
one is cutting more than the other and it's cutting on this side.
Although I set it square it wants to be twisted slightly
The top roller now has cut right the way across just I will just feed it in see how we go.
Now when you cut a knurl don't panic if it doesn't look right first of all.
What you have to do is cut the knurl until the knurl has got the full form.
as you're press into the material the knurling diameter is reducing,
you're getting fewer if you like teeth on the part you're making so sometimes it looks
a complete mess but as you put more and more pressure on you go in deeper
it sorts itself out and once it gets the teeth on the knurling tool in the groove with the teeth on the part.
It then start producing the knurl properly
so eventually the knurl will form if one sides cutting more than the other
either higher or lower your tool so that the other wheel comes in so they're both pressing on equally
and frequently use your wire brush to take off the bits and pieces of swarf
Now that knurl I'm happy with that that's okay I could do it more but if I go too
deep all I'm doing is putting a sharp point on these so I'll rub that over
with some emery just to take any sharp edges off so that's the knurling done.
Now because I've put an knurl on there what I've done is actually put a sharp edge
on both sides because the diamond pattern has pushed out material
to both edges I'm just going to re-chamfer the two sides
I've reset that to finish this diameter off inside
12.42mm so I'll leave it at 12.42mm do the other side and then finish off
12.44mm so now i've got both sides to the right depth I can straighten it all up
12.44mm if this is too big it will foul onthe cam on the tool post
if it's too small you risk cutting into the thread
which is 8mm so you've got about 2mm each side of the thread on that.
so we finished the head we finished the centre the next job is to form the base which is 3mm wide
and I've changed the tool for my parting off tool, this tool has a 3mm wide tip so I'll touch the tip on the side.
zero my compound slide wind it out and move it in 6mm
I've slowed the speed down lets see how these cuts and I'm steadying the end with the revolving centre
I will try it slower
Now we've cut that off the next job is face this off and chamfer the edge
I've just held an 8mm caphead in the three jaw chuck
I'm screwing this up so that the face of this knurled part touches the chuck jaws
it should straighten it up see how that's running
okay so all I want to do is face this off now on the front. Check the width.
Were aiming for 3mm half a mil to come off the front.
That'll do 2.95mm all I need to do is put a chamfer on the outside edge
There's the one we've just made the only difference is it's got a slightly bigger head
and the diameter should be 21.23mm
I think I wanted it a millimeter bigger 22mm
here's the screw we've just made fitted to the tool holder it just drops inside there locks in position
easy to move up and down and you can see
down the side here it's about two millimeter now under the cam that locks it in position
so I'm happy with that one
here's another one I made this time I put a straight knurl
what I have now is the thread cutting tool in the tool post
but it's on its side so I'm just using the point of the thread cutting tool
so I come in just touch the face wind out set it to zero on the compound slide
go in 0.1mm go across the face and then halfway across the other side
scribe a mark
so you can see the full line and the half line the reason for that is
if you're doing milling your holding something in here to mill it in the lathe
you've got an idea of how much cut you're putting on
if you know what the thread pitch is
this one is 1.25mm thread
so I know one division is one point two five
half of division is 0.625mm it gives you an idea where the tool height is on the thread
and then if you want to move it lower it a millimeter
you know it's virtually one turn
What I find is when you put the same tool in the lathe.
The position of the line when it's on center will virtually be in the same position
Theres two on the right that I've just made the one on the left was an original Chinese copy
the difference between the two on the right is one's got a straight knurl and one's got a diamond knurl
Well that's it for today I hope that was useful hope you enjoyed it and we will see you next time
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