Anyone want to re-sharpen drill bits again......

[Oldpath05]

I have the smaller Drill Doctor for up to 3/8 bits, works good for those, but my bigger drill bits up to 1/2" are getting dull and they are cobalt and I have some HSS. I use to have the bigger DD but I found that the $30.00 wheel wore out too quick on those bigger drill bits, like after two dozen sharpenings I wasn't getting that nice chisel point , I think the wheel is too small for bigger bits.

I watched several youtube videos and they all have one thing in common. They go> "first let's talk about the first thing first,>>the rake, geometry, cutting edge, relief and good grief, bla bla bla. For just once I like to see a video on sharpening drill bits and say, the first thing first is the GRINDING WHEEL, what type, what grit, what size, what color and why..........for the average 6" bench grinder, now I'll go watch some more ytube and look for an education on grinding wheels and deals.

 

[dragoneggs]

I'm with you. I would love to know more about grinding wheel materials and what to use for what.

 

[Leejohn]

With the youtube videos, if they have there rubber gloves on don't waste your time watching.

 

[texasranger556]

It's probably not mentioned because geometry of the bit matters way more than what the grinding wheel is made of. I use whatever is available. Never tried a drill doctor personally. I do use the side or the wheel rather than the edge because it's usually flatter.

 

[PILOON]

I sharpen drills all the time with a simple grinder that is fitted with a fine stone using my eyes as my guide.
I simply duplicate the existing angles and always cool the bit by soaking in water.
Heat is the enemy.
The handiest gadget I have is a diamond dresser so that my stones are always flat and true.
The dresser was actually very inexpensive.
Anything below 1/8" is a throw away however but then there are tons of 'deals' out there for assortments of small bits.

 

[Spanner]

... Never tried a drill doctor personally. I do use the side or the wheel rather than the edge because it's usually flatter.

This is dangerous. (Not the DD - They're awesome!) I mean the use of the side of the grinding wheel.

Rotating grinding wheels are covered by an Act of Parliament in my country and in the UK. Similar legislation in USA exists and comes under your OSHA.
Don't scoff - People have died and been injured horribly by grinding wheels 'exploding'. A major cause of grinding wheel failure is "Side-Loading" by applying work to the 'flat' side of an abrasive wheel.

Grinder wheels are only designed to have the work applied radially. That is: from the front of the machine towards the axle shaft. Not from the side.

Some Do's & Don'ts:

Safety Information
Grinding Wheels are Safe Use but Don't Abuse

Do

Do always Handle and Store wheels in a careful manner
Do Visually Inspect all the wheels before mounting for possible damage
Do Make Sure Operating Speed of machine Does Not Exceed speed marked on wheel, its blotter or container
Do Check Mounting Flanges for equal size, relieved as required & correct diameter
Do Use Mounting Blotters when supplied with wheels
Do be sure Work Rest is properly Adjusted on bench pedestal, and floor stand grinders
Do always Use Safety Guard that covers a minimum of one-half the grinding wheel
Do allow Newly Mounted Wheels to run at operating speed, with guard in place, for at least one minute before grinding
Do always Wear Safety Glasses or some type of approved eye protection while grinding
Do Turn Off Coolant before stopping wheel to avoid creating an out-of-balance condition

Don't

Don't use a wheel that has been Dropped or appears to have been abused
Don't Force a wheel onto a machine Or Alter the size of the mounting hole If a wheel won't fit the machine, get one that will
Don't ever Exceed Maximum Operating Speed established for the wheel
Don't use mounting flanges on which the bearing surfaces Are Not Clean, Flat And Smooth
Don't Tighten the mounting nut Excessively
Don't grind on the Side of conventional, straight or Type 1 wheels
Don't Start the machine Until the Safety Guard is properly and securely In Place
Don't Jam work into the wheel
Don't Stand Directly In Front of a grinding wheel whenever a grinder is started
Don't grind material for which the Wheel Is Not Designed

Source: "Grinding Wheel Institute"

Got Grinders? Get Safeguarding - Machine Safety Blog

There is much info on your OSHA site:

"A Partial List of Accidents Involving Grinders" including 7 fatalities on the first page alone:

Safety and Health Topics | Machine Guarding - A Partial List of Accidents Involving Grinders | Occupational Safety and Health Administration

 

[sandman2234]

Spanner is not blowing smoke, he is spot on with his warning, please...please listen.
As mentioned, wheel dressers are cheap, buy one and use it.
David from jax

 

[texasranger556]

Point taken, but if you put enough pressure on a drill bit to cause side loading on the wheel you'll overheat it as well. Just barely kiss it.

 

[GLyford]

If you don't like wheel dressers, there are diamond dressers and dressing sticks (stones). My tool rest doesn't work well with a wheel dresser, so I got a dressing stick and have been much happier, since now I actually use it.

Amazon.com: Grinding Wheel Dressing Stick: Home & Kitchen

 

[George2615]

I do the same as Piloon. Replace smaller bits with new and hand sharpen larger bits on a fine wheel stone. Use a diamond dresser to keep stone flat. Tried a Drill Doctor several times but never had any luck getting a sharp bit.