Joseph Gwinn wrote:

Was the heel of the boring tool skating on the side of the hole? It doesn't
take much. This has snuck up on me.

It looks like at some point, likely before I started, since I did a touch up, I gave the
leading edge some negative rake by accident. In my mind, it all works out to fit the
condition. I *really* need to invest in some Circle Trigon small diameter boring bars
that use inserts.

Today at work was strange. One of the engineers bought a new 1 ton Dake arbor press. I
think it was made in USA but it might not be. He wanted a .501D by 1.00 dp hole in the
center of the ram.

First time I used the 4 jaw for the LeBlond at work, usually there I use a Buck 3 jaw true
set or collets.

After cutting 4 strips of bar stock to protect the ram from the curved jaws, I got my
first crack at centering square stock in a 4 jaw independent. It went okay, you rock the
indicator near where you think center is and remember the low reading. This was made a
bit more difficult since the only indicator I have at work is a 0.0001" .016" travel test
indicator. If I knew I was doing this today, I'd have bought one of my long travel
plunger indicators in with me from my home shop.

Anyway, got it all nice and squared up, center drilled it, drilled it, run a reamer into
it. All went fine and dandy using HSS tooling. I was a bit worried it might be fairly
hard but it sure seemed in HSS territory.

So next I take it over to the bridgeport. Use my center finder to find the edges of the
Kurt vise. I *wish* people would just leave the dro on. There is a button on the Sony
DRO to mute the display.

Now to drill a 1/4" hole so I can tap a 5/16 NC hole. The speed I use for the edgefinder
should be fine for a 1/4" drill. I am working my way down to center making nice looking
chips and all is well. Suddenly, I hear screeching and all progress stops. Pull the
drill and it is cooked. Okay, try another new one. DOA.

Try one more from my drilldex in case I have some crappy stuff. DOA.

I'm about .050" from breaking through into the .501" hole. This is p*ss*ng me off at this
point.

Head over to my tool box and find a 7/32 carbide drill I use to modify normal sockets to
accept 1/2" pin lock square drives. That punches right through. I also found a 1/4"
endmill that I am guilty of using in a drill chuck today since I just wanted to get this
ordeal over. No harm came to either.

So now I'm tapping this thing. Visions of a broken tap dance in my head and I really
don't want to break one. I go a bit and really don't like the forces I'm putting into it
and get another one from supply. That one cuts a bit easier but I can tell it doesn't
like what I'm asking it to do. Finally, I break through.

Now at this point I try to screw a 5/16-18 screw I pulled out of another arbor press when
I grabbed the tooling to use it to check fit. It will not screw in. It is the right
pitch. The tap I used was H3 or .0015" on the loose side. I head over to the bolt bin
and get another bolt, it fits fine, I champher the original fastener and it still doesn't
want to go on.

I compare it to my tap, perfect match. Go find a metric bolt near the size and it isn't
close so it isn't one of those deals.

Then there was the MCC I replaced in a CNC lathe, I didn't notice one contact was NC when
I expected NO, that took a while to figure out.

Some days you fight your way though.

Wes