Sharpening drill bits by hand

[widgitmaster]

Do you sharpen drill bits by hand on a bench or pedistal grinder?

Yes I do it all the time!
No, they never cut right!
Sorry, I don't know how to do that!
Its better to throw them away!
No, we have a drill sharpening machine!
What's a drill bit?

[Mcgyver]

do it all the time, or at least did until i made my drill sharpening jig. Hand sharpening of twist drills seems to be one of points of delineation between those who really know what they are doing and and those that don't. It shouldn't be that way though, its just not that tough to do. It does take some skill vs just plain old knowledge, but that will come quickly with some practice and everyone should learn how, its a basic shop skill. with a drill point gauge, nicely dressed wheel and a spare 3/8 bit, long before you grind your way through that bit you'll have the hang of it!

[Geof]

Originally Posted by Mcgyver ....... its just not that tough to do. It does take some skill vs just plain old knowledge, but that will come quickly with some practice and everyone should learn how, its a basic shop skill. with a drill point gauge, nicely dressed wheel and a spare 3/8 bit, long before you grind your way through that bit you'll have the hang of it!

Mr Mcgyver I could not disagree more!!!! I have demonstrated the procedure to, and tutored in drill sharpening techniques, many, many people. There exists a percentage which I put at around 20% that just never get the knack. It is like any other acquired skill, some people pick it up almost naturally, some will get there over a variable time period with persistence and practice and some will never get there.

[lakeside]

At today labor rate and the fact that you can never really grind a drill point with both flutes cutting at the same time unless you use a comparator. The cost to grind a drill in other than a home shop or to be used in a manual machine is not worth it for a 3/8 drill. As a note I did tool grinding for 10 years and can split point. But unless there is no new drill a regrind will only be use if it the last option.If your a job shop I can see why you would, but a manufactor would not was the time Boston shop rate $95h/60m=$1.58/min x 5min(regrind time)=$7.50 what the cost of new?Buy a dozen at a time and send out for regring when you have many to do The shop we send to charges $2.50/drill under 1/2 and that is with a split point

[Bubba]

When I was young my Dad (machinist all his life) tried to teach his dumb arsed son how to do it. However, I could just never quite get the hang of it. Well many years have passed (along with my Dad) and a friend (Mentor) got me to doing it in 15 min!

Being out in the country, I can't just run down to the nearest supply house especially on a Sat. or Sun. when I break the cotton picken drill. So this skill is handy to have for those times as well as when you need a different point for some specific material to drill a couple of holes and finish the project. No matter how many drill you try to keep as backup, there are times you NEED to have the skill!

[lakeside]

If there one area that we as a trade have lost it is the manual tool grinding of both mill and lathe with most shop going to insert tooling the young guys just don't have the opportunety to do this much and it's a skill as Bubba said we need at times

[Mcgyver]

Originally Posted by Geof Mr Mcgyver I could not disagree more!!!! I have demonstrated the procedure to, and tutored in drill sharpening techniques, many, many people. There exists a percentage which I put at around 20% that just never get the knack. It is like any other acquired skill, some people pick it up almost naturally, some will get there over a variable time period with persistence and practice and some will never get there.

forget 20%, did you know half the people out there are of below average intelligenc?

Geof, or shall i call you Colonel Pickering, A sad portion of that 20% maybe people who just don't have the capacity to learn, and a still sadder portion might not want to learn, but i maintain that most of us, if we puzzle out the shape of a well ground bit, the motion we'd have to give it across the wheel to obtain that shape and a way of measuring (and understanding why) the lip length and angle, could be taught. next thing you know we'll have wager going 'the rain in spain......"

Lakeside i see your point for production, but for commercial jobbing, maintenance, toolroom or home (as you point out) it's neccessity - a skill that would be beneficial to acquire, most probably have it except for many of the home shop guys. I mostly use the T&C grinder now because drills sharpeded with it are so accurate, but thats a luxury few have and and mostly drilling isn't a precision op (oops there's another pandoras box) .

[dertsap]

i sharpen large drill by hand , i ve seen lots of guys who can sharpen a drill then blow it when the try to split point it , i can t tell you how many times i ve picked up a drill and someone has ground across the cutting edge leaving a negative rake at the most critical spot on the drill , which is at the point , i don t know how these things cut sometimes

[lakeside]

Originally Posted by dertsap i don t know how these things cut sometimes

shear & horse power

[Geof]

Originally Posted by Mcgyver ...Geof, or shall i call you Colonel Pickering, ....... but i maintain that most of us,....... could be taught.

I have been called a lot worse than 'Colonel Pickering' so I will not quibble.

Regarding your other point in your first post you said "everyone should learn how" with which I disagreed; (does my grammar come up to a Higgins' standard?) now you "maintain that most of us......could be taught".

I will respectfully point out that 100% - 20% = 80% and I think most of us will agree that 80% is most of us. Which is probably the first time Pickering and Higgins agree .

[Mcgyver]

ahhhh but my dear Colonel Pickering, everyone should and most could, the two are not incompatible. its splitting the point that we are having difficulty with

[dertsap]

in my opinion and experience that there is only a small percentage of machinists who do things properly in the shop ,be it stupidity or laziness ,
this is what makes us professionals , not everyone can do it ,