Tool Grinding

[rake60]

We have had several questions and very informative posts here on the
subject of tool grinding. The "book" details all of the proper angles and
required geometry of a tool.

(Here he goes with another story... :)

The very first time I has to hand grind a tool my salty old mentor was
watching my every move. The edge chipped on that tool at the moment of
contact with the workpiece. Back to the grinder, I made some adjustments
to my original tool and tried it again. My second attempt started to make a
chip but the edge burnt up in just a few seconds.
Now my mentor was fired up! He came over and ripped those tools out of my hand.
He took a 12" scale out of his back pocket and held each of them up to the
ceiling lights one at a time with the edge of the scale lined up to the cutting edge.

I will never forget his advice...
"You're trying to slice bread with a :redface2: brick!"
He did have a way with words!

He said; "What's cutting needs to touch. You want as much beef supporting that
cutting edge as possible but everything behind that edge has to clear the workpiece."

I learned how to hand grind tools that night.
I didn't need a fixture or angles from any book.
Once you understand "you can't slice bread with a :redface2: brick".
it's easy to get it right.

Rick

 

[Artie]

I hear what you are saying Rick, I think a lot of us had similar 'experiential teachers' in our (long) years... my gem is simply.."you never learnt anything with your mouth open boy"..... That was from Bruce Hodson.... he must be 2000 years old now...still going though.... what he was saying is a variation of "you have one mouth and two ears so listen twice as much as you talk...."


Most of my early tool grinding were able to cut but didnt last so very long, things are a little better today... but hell do I have some wierd looking cutters in the old box......

;D

Rob

 

[black85vette]

When I took machine shop at the local Vo-Tech a few years ago the old guy teaching the class said that most of us would be using CNC and indexable bits and would not really need to know how but he wanted to show us how to grind tools anyway. Turned out to be one of the most useful parts of the class.

 

[Lew Hartswick]

The other extreme is: "You cant cut bricks with a carving knife" (or scalpel) .
...lew...

 

[BobWarfield]

The other extreme is: "You cant cut bricks with a carving knife" (or scalpel) .
...lew...

Izzat why most carbide inserts are shaped like bricks?

LOL,

BW

 

[New_Guy]

just thought i would say i ground my first tool bit last night, a facing tool out of 12mm HSS with 5% cobalt all by hand and what a great cut it took!!! no one has ever stepped in and said thats they way you do it i learned everything from reading you guys posting how and my trusty black book so thank you guys who have taken the time to go into the details of tool grinding

we need a new sub forum tutorials ;D

 

[Artie]

New-guy... right there is a damned good start! Congrats and well done... is isnt easy and Id say (guessing) that you probably 'couldnt' have done it so early and so successfully with out this forum ... proves the worth of all the folks on here that post.... I like it...


;D artie