Sharpening Drills.....

[thestelster]

I was having fun Peter. My facetiousness was maybe a wee bit too subtle but I wanted to avoid being political.

I suppose I could have said "Canada, is becoming the new China". But now that I'm explaining it, it's not really political anymore.

In the photo of that Lee Valley link, the nameplate on the sharpener says Taiwan.

 

[garageguy]

I have one of the general drill bit sharpeners that I bought 30 yrs ago. it looked so cheap and poorly made that I tossed it on the shelf and left it there till a few months ago. Figured it was $13 wasted on a piece of junk. So a while back I got bored and figured I would give it a try. It actually works pretty good. Very poorly made, but it works. The instructions say up to 1/2in. so I tried some larger sizes and found that the cutting edge chips completely off.

 

[Mcgyver]

I was having fun Peter. My facetiousness was maybe a wee bit too subtle but I wanted to avoid being political.

I suppose I could have said "Canada, is becoming the new China". But now that I'm explaining it, it's not really political anymore.

You guys are really trying to push my grumpy old man buttons aren't ya? Lee Valley, the evolution of what was a great store for woodworkers into a gift shop, and Tim Hortons....that those purveyors of crap food and weak coffee get cast as a national icon is oh so embarrassing! .

Sharpening by hand works, but its nicer and easier having them ground accurately so they cut to size. I batch them and can do one in a minute or two when the rhythm is going so yes, sharpening drills, even small ones, is quite economic (granted, just doing one would take awhile, setup etc). They cut to with 2-3 thou....get that geometry a mirror image on each lip and they will do so.

Here's a Canuck made drill grinding fixture. works from close to nothing to 1" The problem with some fixtures is holding the drills. As the diameter goes up, the land helix gets really long meaning you need a long fixture to get enough contact. Collets are a problem for that with large drills for instance - the land surfaces are so close to parallel to the axis, that the drill isn't held firmly.

 

[thestelster]

You guys are really trying to push my grumpy old man buttons aren't ya? Lee Valley, the evolution of what was a great store for woodworkers into a gift shop, and Tim Hortons....that those purveyors of crap food and weak coffee get cast as a national icon is oh so embarrassing! .

Sharpening by hand works, but its nicer and easier having them ground accurately so they cut to size. I batch them and can do one in a minute or two when the rhythm is going so yes, sharpening drills, even small ones, is quite economic (granted, just doing one would take awhile, setup etc). They cut to with 2-3 thou....get that geometry a mirror image on each lip and they will do so.

Here's a Canuck made drill grinding fixture. works from close to nothing to 1" The problem with some fixtures is holding the drills. As the diameter goes up, the land helix gets really long meaning you need a long fixture to get enough contact. Collets are a problem for that with large drills for instance - the land surfaces are so close to parallel to the axis, that the drill isn't held firmly.


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Nice!! Did you make the jig?

 

[Mcgyver]

Yup, my design and build.

 

[thestelster]

Yup, my design and build.

What do you have attached to? A tool and cutter grinder?

 

[Mcgyver]

What do you have attached to? A tool and cutter grinder?

I've got a floor model T&CG and this little bench model, a Chevalier 610. Roughly a knock off of a cuttermaster, imo a little nicer. Made in Taiwan, quality is actually pretty good. I use it for endmills (w airbearing) lathe tools (threading) and drills. The big one I use mostly has a light cylindrical grinder and for the occasional horizontal cutter

It would work just as well on a surface grinder with a cup wheel installed. Very old photo before my shop got crowded!

 

[Degen]

You guys are really trying to push my grumpy old man buttons aren't ya? Lee Valley, the evolution of what was a great store for woodworkers into a gift shop, and Tim Hortons....that those purveyors of crap food and weak coffee get cast as a national icon is oh so embarrassing! .

Sharpening by hand works, but its nicer and easier having them ground accurately so they cut to size. I batch them and can do one in a minute or two when the rhythm is going so yes, sharpening drills, even small ones, is quite economic (granted, just doing one would take awhile, setup etc). They cut to with 2-3 thou....get that geometry a mirror image on each lip and they will do so.

Here's a Canuck made drill grinding fixture. works from close to nothing to 1" The problem with some fixtures is holding the drills. As the diameter goes up, the land helix gets really long meaning you need a long fixture to get enough contact. Collets are a problem for that with large drills for instance - the land surfaces are so close to parallel to the axis, that the drill isn't held firmly.


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Nice 4 face grind.

 

[Downwindtracker2]

I was taught to use both wrists and elbows when sharpening by hand. You'll see the motion on some videos.. Both flutes have to be the same angle. I saw a machinist sharpening drills, he measured both flutes with a caliper. I found I got the correct clearance angle if there was dip between the flutes at the center.

 

[Brian H]

I took the time to read Harold Halls article on drill bit sharpening (http://www.homews.co.uk/page354.html ). Good read but unless I missed it, for jobber bits, using a bench grinder, what sort of stone/wheel is recommended?

I usually have a 1" wide 80-120 grit on my right wheel. Nothing fancy but considering a second "tool bit only" bench grinder... Any preferences for wheel choice would be appreciated (for bit and tool sharpening).

BTW, I've had Drill Doctor for years, must admit, it is incredibly frustrating and darn near useless. Watched all the videos, but can't seem to find anything that spells out how to get a great "bit" out of this contraption.... about the only thing it does well is "splitting bits".... I've just starting using a jig that Harold talks about and pretty pleased with my first efforts, looking at improving the setup.

(PS... I drink too much to sharpen anything by hand ;-) )

Cheers

Martin

I have had a different experience with the Drill Dr. I purchased one on sale a couple years back and was quite impressed with it. I did find that if the bit had significant damage (i.e. a chip or gouge) it took quite awhile to correct. The habit I have gotten into is to use a drill a couple of times then put them in a bucket and once a month or so I spend an afternoon sharpening. I have gotten much better results just using it to touch up bits as opposed to regridsing them.

Also, I have watched many videos on using a bench grinder to sharpen drills and it would appear that I just suck at it... never had any success whatsoever.