welcome to Enots engineering I'm Alan
in today's video we continue from last week where
we set our compound slide to eight degrees exactly by using trigonometry
today I set up my grinding wheel in the tool post
and go through the stages of grinding the bore to give us the 8 degrees
so let's go into the workshop and see how we do it
I've just set the lever indicator up to check the taper in the bore
now that's reading 0.1 millimeter which is around 0.004
and I think what I'll do is try and set my grinding wheel up to follow what I've already set up
we'll see how we can grind that taper
this is the simple brackets I made years ago for my Rotozip
just two pieces of aluminium angle bolted to this part
which has a slot in it and this can be tightened up or slackened to close bore
on the rotors it which is held in here that just goes into my tool post
I set the tool post square to the compound slide so that's why it's it's an angle
we set at a 8 degree angle which is a follow-up from the video that I did last week
and the Rotozip will fit in here this is the Rotozip
it has a small collet on the end you can have two speeds setting
twenty and thirty thousand rpm
it's 240 volts that fits in there tighten up this nut
and I'll leave this power switch at the top there so I've easy access to switch it on and off
just hold it in tighten this up
okay so the next job is to put the grinding wheel in
this is the grinding wheel it's on a mount it's mounted wheel
this wheel needs dressing because it's glazed you can see its got like a shiny surface on it
that means that all the surface has been flattened by the grinding
and there's no rough grit on there
so it's doing more rubbing than grinding
I'll just tighten this up
I've tightened that up
there's a lock on this you can hear it there
there's a button there you press in and it locks the spindle
and that's ready for the wheel to be dressed
now for dressing the wheel I use a diamond
It looks like this
just a piece of steel and in the end is an industrial diamond
the easiest way I found of dressing the wheel just hold it in the chuck
put the diamond through the chuck needs to extend beyond the chuck
tighten up the chuck
then select back gear so now there's less chance of that chuck moving
I can turn it around
what we'll need to do now is just
bring the Rotozip up higher in the it's all post
so that the diamond is on centre line ready for dressing the wheel
what I have here this is a vacuum hose
The Rotozip rotates this way so as I dress the grit is going to come up into the vacuum
I hope
A bit of safety first these mounted wheels all they are is an abrasive that's been bonded to a steel shaft
so when you first use these for the first time
you can see this one it's so far running out it will need dressing
now the first time I've used this one before so I know it's safe wheel
the first time you switch it on stand to one side
because you don't know whether there are any cracks or any defects in this mounted wheel
so anything that goes wrong this will shatter the bits of fly out and if you're standing
where you'd normally stand to turn a bar you'll get that in your face
also safety goggles
and even a mask if you're doing a lot of dressing
I'm going to turn the vacuum on in a minute the lathe is not used at all
all I'm doing is holding this diamond
I'll be using my compound slide to give me the correct angle
because that's the way I want to use it when it's on the job
and we'll just dress this face
so I'll turn the vacuum on first
there's some suction now we'll turn the wheel on
now you can see the wheel is dressed and it's parallel to the angle that I'm going to use it
so it don't need the chuck anymore
I don't need a diamond so I can take these out
and I'll change it chuck now and put the ER 32 collet holder in
the reason why I'm cutting on the back of the hole
Is that I can see easier what's going on inside if I was to cut on the front
I can't see so the lathe is traveling the normal direction
I've slowed the speed down in this case it's 40 revs per minute and I'll be cutting on the back of the borel
I've made sure that the grinding wheel is now on center height tool height
so it should be cutting along here
and I'll be using the compound slide which we set that's 8 degrees in the last video
to do the grinding
so the first thing I need to do is check that the wheel will go into the full depth of the hole
just about there
I'm going to put the wheel inside to start it and then I will start the lathe and put the feed on
so I'll move the camera to a better position
turn the grinding wheel on
Turn the lathe on
you can see the type of finish you'll get
it all depends on the grit on the wheel that you using and how fast you move the wheel in and out
but the finish is reasonable for the for the part I'm happy with that
you see there it's rubbing in the middle
middle on this one middle again on that one just put that in the collet
I can't remember what it was last time when I tried it
0.002" or 0.003" I think it was
I'm not going to grind anymore out so I will change my grinder now to the dial indicator
Run out that is about just under 0.002"
and I know the bores running true because I've just ground it
and I've not moved it
so obviously that's the collet
look inside the bore you can see I've ground right the way down to the bottom
well there we are grinding in the lathe easy way to correct some run-out or just
a taper slightly it doesn't remove much material and it gives a good finish
Thats it for today hope that was useful hope it was interesting look after yourself
and we'll see you next time on Enots engineering