Hello welcome to Enots engineering I'm Alan in today's video we'll be making an
attachment that fits on a dial indicator so you can measure the run out of a
bore without changing the dial indicator.
This attachment fits on the end of the
indicator spindle it clamps on and you can swivel into position when you need to check a bore.
It's got a ball bearing on the top that's soldered on the shaft and a locking screw so you can lock it into position.
So let's go into the workshop and see how we make it
I've just put a piece of silver steel the lathe
Im turning this down to 5mm
I've just fitted my radius attachment on to the cross slide by removing the
compound slide these fits into the compound slide dovetail
I've just set the tool to give me a radius so what I'm going to do is bring this up to the bar
so I can get a touch on it there, move it in until I get it touching the edge
I just want to blend this sharp corner in here with the radius
now I finished the center drill hole and that holds this 5 mm ball bearing
and as long as the shaft is below 5mm you know that it will touch the side of ball
The next thing I need to do is put my indexing feature on and make two
flats on this shaft here ready to drill some cross holes
So I'll set my fixture up and we'll mill the flats on.
I fitted the indexing fixture in the tool post
squared it up put the workpiece in the indexing fixture and in the headstock
I've put the end mill I just want a machine a flat on each side of this part
and I flat on the top
now I will index it round
turn it 90 degrees
I've got to drill a hole through this side and a hole through this side and tap it M3
so I put my centre drill in and what I'm doing is just touching
the centre drill the side of the part
using the feeler gauge just to feel when it touches
thats just gripping it so now I know that that drill is 0.003"
This is a 0.003" feeler gauge its 0.003" off the edge of the bar I know the diameter of the center drill is 0.116"
and I know the diameter of the part is 0.253"
so I'll lift this up now knowing that it's three throw off the edge
bring it in 0.003" so I know now that the cutter is on the edge.
wind it in half the diameter which is 0.126"
and then half the cutter which is 0.058"
that should put that drill in the center of the bar
The hole that you drill should be big enough to fit over a dial indicator
so now I want to drill another hole on the other side
this one goes through where the two flats are
another hole here to go through for the locking screw
what I've done is drilled halfway through the thread so the threads on the
bottom side is full and when I put the slot in I've put the slot to one side
So i've got more thread on the bottom for the cap head to grip.
I always remember what my metalwork teacher told me when I was at school when soldiering.
fish-and-chips frying tonight
fish fit the parts and check that the parts fit okay
chips clean the surface to be soldered
frying flux the parts to be soldered
tonight tin add a layer of solder to the surface
now I want to fix the ball with solder into the hole on the end
so the first thing I need to do is put some flux in there, heat it up and then tin the joint with some solder
If I heat that up again it should solder on
Take that out all I've got to do is with some emery cloth just take off the solder
thats run down the side clean it up a bit and that's finished.
often you need to check both the outside and the inside now that would normally involve changing the DTI
to leaver type to get in or an attachment on the dial
indicator to be able to put the probe into the bore
so now what I've done with this is you can just turn this out. It stays in the upright position normally,
and when you need it just turn it around
using the allen key just nip it up then you
can go into the bore without having to change your dial indicator
and check the run out on the inside of the bore.
obviously you have to go to the back of the bore so that the run out is pushing
the indicator in and out, you can't do it on the front otherwise it's pulling the indicator
that's got a 0.002' run out
turn it to the upright position
which has a 0.002" run out, move it out turn the end to get the attachment around
Tighten it up move it to the bore
obviously the closer this ball is to the stem the more
accurate it will be you will get a bit of spring in this depending on how much
play you've got in the spindle
well that's it for today I hope that was useful and we'll see you next time on
Enots engineering