Hello welcome to Enots engineering today I'll start making a drill grinding attachment
Now I've looked on some YouTube videos there are various methods
are grinding drills there are lots of methods lots of different fixtures and
fittings but I wanted something to fit the Worden as I've got a Worden tool and cutter grinder.
I've made some drawings looked at some ideas and
decided to have a go at making a drill grinding attachments.
So today we'll start by making the top block and the spindle locking screw.
This is the tool and cutter grinder table this is the work piece adjuster this is an ER 20 collet holder
I made that fits in there Now for grinding drills thats OK for
small drills the problem I have when you come to the longer drills and the morse
taper drills this doesn't fit in there because the adjustments on the bottom
here and the drill sticks out far too far so what I need some sort of
attachment that can fit on here where the drills become further down into here
and I can get the longer drills in so I can grind those so that will mean
removing the feed from the end of the unit.
I also need to be able to turn the whole thing 180 degrees.
so that I can grind the second face of the drill.
I need some way of turning the collet round rather than taking this block out
so I need to replace this with an attachments specifically made.
So lets go into the workshop.
This is an inch square steel bar and it's about 80mm
long so what I want to do is get this true because I'm going to bore
a hole straight through in the middle and I need to get it perfectly centred
on both axes so that the hole is central to the outside.
When you need to protect your work from indentations from the chuck jaws.
If you get yourself the lid of a tin can. Cut off a strip that will go under the
chuck jaw lift it up and just bend it over and then when you tighten your
chuck up it'll tighten up on this and not damage the surface.
I've set my dial indicator in the tool post and I've set the tip so it's just on center line it's not critical.
So what I'm doing now is just turn the Chuck by hand till I get
the lowest reading on the flat of the square. Zero there and note the small
dial is on zero as well so you pull the indicator back rotate the Chuck 180
degrees to the opposite side and get the lowest reading on that it,s just below
zero so that needs to come towards me you keep adjusting the two sides.
two opposite sides then you go on to the other side of the square.
Zero that there get the plunger out of the way turn it around 180 deg
couple of tenths down.
let's do that at zero
two tents down and keep adjusting the jaws until you're happy with the reading you get.
Once you've got it running true. We face this off.
just brushing it with oil
I,ve fitted the boring bar in the lathe and you can see there the overhang of the
tool is about 90 millimeters and I need that because this hole all I'm doing is
80 millimeters long so I'm going to put the tool the back of the bore and come
forward
I think I might be getting a bit too much vibration there.
I've changed the boring bar
from this one which was bit flimsy when it was hanging out
the tool holder by 80mm to this one which is just a bar of silver steel with
a tip in and on this side there's a grub screw which just told the tip
going through a hole
Put the travesty reverse
Here you can see the finish on the bore. I,ve finish boarding the bore to 18mm
Now what I've done is marked up don't know if you can see it there.
I put two marks on the boring bar one at 20mm in
from the face and one at 60mm
and what I want to do is go into the bore and put an undercut between the 20 mm and the 60mm
so we've bored out the bore to size we put a recess 20mm in to 20mm in
each end we faced it off chamfered.
So on this end need to face it off to length
and chamfer the bore.
All I need to do is file off the sharp corners.
We've got the square block with a hole through.
Machined to length the next thing I want to do is drill a hole
through across the corner because this is the widest material and tap that to
take a screw and then later I'll be drilling two holes through the bottom
and tapping those to take bolts to bolt it to the the base so this hole for the
middle on the diagonal is to take a thumb screw to lock the spindle.
I,ve just machine a small flat on the diagonal to guide a 4mm drill ready M5 tapping.
I,ve now tapped that M5 and I'll just take these sharp edges off
Now that holes for a five mm thumb screw.
So let's make the thumb screw.
Brass about 16mm diameter.
I just want to clean the outside up put a knurl on here
reduce the diameter and put a M5 thread on there.
Next thing I'll do is put the knurl on
that's okay
5.06mm that will do.
Now I need to make the end bit clear of the threads.
So if it does peen over in use its not going to lock up on the threads.
I'll take another 0.5mm off which is a mm on the diameter.
that's ready for the threading.
I fitted my die holder in the lathe a M5 die in there
this is just a holder that can slide up
and down on this bar which has a number two Morse taper on the end and
it's held in the tailstock this is free. Free to move in and out
I'll just bring it up to the tailstock I've got my handle on the end of the
headstock so by using both. I just feed this in until it cuts.
and the tail stock keeps the bar square and the die square
Just feed it along the thread
I'll just stop before I hit the face wind it back out.
I,ve taken the tailstock lock off so it can all slid back if need be.
Theres the thread.
I've put my parting off tool in
I just want to make an undercut on the end.
Cut a small groove ready to part it off.
Now before I part it off I need to put a chamfer on each side
I have a small piece of brass with a 5 mil thread in it.
I just hold this in the chuck. Screw the thumb screw back in.
Take off the pip and make a little indentation in the end.
Just polish that up now with some emery.
that's finished that fits in the block we've just made to lock the spindle
Oh well that's it for today
and we'll see you next time
On Enots engineering