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View Full Version : Drill bit sharpening. Success, kinda.



hitnmiss
02-25-2008, 10:12 AM
Mounted a winch bumper on my 4x4 over the weekend. Need to drill several 3/8" holes thru ~ .188" steel. 1st hole was a bear and took all I had to push the drill. So I decided to have a go at hand sharpening the bit (harbor freight ti coated set that's served me very well in the past)

Just stuck the bit at a close angle and ground, then relieved it by rolling up.

Thought "No way this will work" Stuck it in the drill and sure enough not a chip, till I realized it was in reverse. Sharpened again and the prettiest curls came rolling off the bit with maybe 10% of the previous pressure needed. Drilled 6 holes with that bit after sharpening.

Doubt it would cut a on sized hole now but it sure did good for the low precision bumper mounting.

Lew Hartswick
02-25-2008, 07:04 PM
See it "aint rocket science" :-)
...lew...

SteamChEng
02-26-2008, 10:37 AM
My old man - career at sea as a merchant marine engineer - used to say that one of his most valuable skills was the ability to sharpen drill bits by hand. He had a great eye for that kind of thing, and was a stickler for detail.

He was also a great machinist. Got him his first deep sea job in 1940.

SteamChEng

Alistair Hosie
02-26-2008, 11:16 AM
Lew lew lew!!!



See it "aint rocket science" :-)
...lew...
it's not rocket science







wot yoo sed aint rite so it aint:DAlistair

Norman Atkinson
02-26-2008, 03:23 PM
Has anyone thought that that there is actually more to life than being able to sharpen a drill bit by eye?

Now I'm going to get lambasted but for those like me and Archimedes who can do geometry, they will realise that slot drills are sharpened by the four facet method.
You don't know what the Four Facet system is? Well think what you must have been missing all these years.

There is a Six Facet System but it also only works with the two times table as well. One thing, it ain't rocket science!

Gosh!

Norm

jim davies
02-27-2008, 12:35 AM
The wife insisted on a thirty facet system on her ring finger to be installed at the ceremony...personally I think being able to grind a drillbit is more fulfilling :-)

Bill Pace
02-27-2008, 08:13 AM
I pretty quickly was able pick up a metod to hand sharpen a drill bit to a very useable condition, spitting out chip/curls, getting holes in metal seemingly easy, ---and went for years thinking nothing about it ----- until I got to hanging around this bunch here on the forum!!

If you read thru all these posts long enough, you finally absorb some of the info .. by osmosis, if nothing else,--- and proper sharpening techniques finally began to sound like I wanted to DO it. So, with info from here --- and mostly Lane! --- he & I started pursuing a Darex...that we could afford!!

With scouring ebay, we were able to get a couple nicely made-up units at not too bad ....
http://bbs.homeshopmachinist.net/showthread.php?t=27302&highlight=darex

Now that a few weeks have passed and have had the opportunity to use several of the resharpened bits, I am just totally amazed at the difference!! Such pretty curls/chips, such easy feed pressure, straight holes (With little more than 'eyeball' setup I ran a 3/8" thru hole 3" yesterday and it came thru .004 off!, that wouldnt have happened with my hand sharpened!)

Yeah, I know .... not a lot of HSM'ers are gonna be able to swing a Darex (they ARE pricy, even with scrounging ebay), but from the seemingly positively changing comments on the Drill Doctor, and some real changes to the machine, it might be a viable alternative...

There REALLY is a BIG difference in my hand sharps