Date:         Fri, 28 Jun 2013 09:42:30 -0700
Reply-To:     Alistair Bell <albell@SHAW.CA>
Sender:       Vanagon Mailing List <vanagon@gerry.vanagon.com>
From:         Alistair Bell <albell@SHAW.CA>
Subject:      Re: Friday: drill bit sharpening
Comments: To: Larry Alofs <lalofs@GMAIL.COM>
In-Reply-To:  <CA+r=JhpVKmJMeF3B2GB6puNUx8GzgAx6RVnPiT3-s7F36aAVCQ@mail.gmail.com>
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I've tried a few methods (but not the drill Dr.). Freehand on grinder/stationary belt sander, the device that attaches to grinder and works on side of wheel, and the little Eclipse hop along guide that runs on sandpaper.

Most of the time, for drills 1/4" and up, i do it freehand on stationary belt sander. I've marked some lines on the sander's table (59 and about 54 degrees) as a guide. It is hard to describe the motion you use to grind on sander or grinder, but I think there are vids etc online. I was taught by a good machinist and he made it look easy. It is surprising how well you can do it freehand, but it takes practice.

I'd advise looking online for vids and practicing on a 3/8" bit. Study the geometry of the bit and you will understand the principle behind sharpening them. One trick I use often is to blacken the end of the bit with a sharpie then try the bit out on some aluminum. Where the black comes off shows where the bit is cutting OR rubbing. My tendency is to not grind off enough behind the cutting edge and the heel rubs. The sharpie trick shows that up clearly.

As does how well the bit cuts of course :)

Once you get the knack of freehand sharpening is very quick. 

Very small bits, 1/8" and smaller, I don't sharpen. Haven't been able to do a good job on them.

Oh, and buy the best bits you can afford. Cheap bits are a total waste of time.

alistair


On 2013-06-28, at 8:51 AM, Larry Alofs wrote:

> Hi,
> Looking for advice about a drill bit sharpener.  Any brands/models that
> people can recommend?
>  Something effective but not too pricey, if that's possible.
> 
> Related question: Any opinions about TiN coated bits?
> 
> Thanks,
> Larry A.
>  had to drill some rather hard stuff