You can do it by free hand and a little bit "feeling" or use some cheap jig for it. Just look at the drill and try do the same. With a jig it's easier.
Art no 30-4819 at Clas Ohlson, just an example.
Costs 9-10 USD in Sweden.
Art no 30-4819 at Clas Ohlson, just an example.
Costs 9-10 USD in Sweden.
I've been using the Drill Doctor for a couple of years and it does a great job. The only major problem is with Zirconium coated bits, they tend to chip instead of getting sharper...
http://www.drilldr.com/
Hope this helps!
http://www.drilldr.com/
Hope this helps!
A post on rec.crafts.metalworking from the legendary Teenut, R.I.P.:
http://groups.google.com/groups?selm=wo%a6.122360$Z2.1496348@nnrp1.uunet.ca&output=gplain
Tim
http://groups.google.com/groups?selm=wo%a6.122360$Z2.1496348@nnrp1.uunet.ca&output=gplain
Tim
Hi Koy,
It's real tricky to do well, but here are a few pointers and an illustration.
The tip should be ground at about 118degrees included angle. a smaller angle (pointier) for softer materials. The cutting edges should be equal length and parallel. The web should form a chisel point at about 110degrees with the cutting edges. The relief should be ground back from the cutting edges at an angle of about 5 to 15 degrees. The softer materials get a steaper relief.
When grinding, hold the drill with the cutting edge parallel to the floor at just above spindle height on the grinding wheel. The drill should be held so the cutting edge is also parallel to the grinding wheel surface (about 59degrees from straight). Now drop the shank for the drill down about 5degrees and you're ready to start sharpening.
Move the drill into the wheel and as it starts to make contact, move the shank down and the tip up asyou move the drill in toward the wheel in a smooth motion. Rotate the drill 180degrees and do the same on the other cutting edge. Alternate from one edge to the other making sure they remain the exact same length and parallel to each other.
Practice on some junk drills to get the hang of it. The shorter the drill gets the thicker the web becomes. It's even trickier to thin out the web, but it can be done.
...or you can go buy a drill sharpener from the hardware store. In any case, have fun.
It's real tricky to do well, but here are a few pointers and an illustration.
The tip should be ground at about 118degrees included angle. a smaller angle (pointier) for softer materials. The cutting edges should be equal length and parallel. The web should form a chisel point at about 110degrees with the cutting edges. The relief should be ground back from the cutting edges at an angle of about 5 to 15 degrees. The softer materials get a steaper relief.
When grinding, hold the drill with the cutting edge parallel to the floor at just above spindle height on the grinding wheel. The drill should be held so the cutting edge is also parallel to the grinding wheel surface (about 59degrees from straight). Now drop the shank for the drill down about 5degrees and you're ready to start sharpening.
Move the drill into the wheel and as it starts to make contact, move the shank down and the tip up asyou move the drill in toward the wheel in a smooth motion. Rotate the drill 180degrees and do the same on the other cutting edge. Alternate from one edge to the other making sure they remain the exact same length and parallel to each other.
Practice on some junk drills to get the hang of it. The shorter the drill gets the thicker the web becomes. It's even trickier to thin out the web, but it can be done.
...or you can go buy a drill sharpener from the hardware store. In any case, have fun.
Attachments
Hats Off to Rodd
Lucidity at it's finest.
That being said it is an aquired skill. I learned away back when with ruining a bunch of bits. My advice is buy three or four 3/8" bits that are cheap and keep one as a control. Practise on the rest untill they look the same and then try using them and find out how you are actually doing. It will not happen instantly but you will pick up the knack for how to hold the bit and how much to grind off to get the little monster sharp. Practise makes for perfect.
Mark
Lucidity at it's finest.
That being said it is an aquired skill. I learned away back when with ruining a bunch of bits. My advice is buy three or four 3/8" bits that are cheap and keep one as a control. Practise on the rest untill they look the same and then try using them and find out how you are actually doing. It will not happen instantly but you will pick up the knack for how to hold the bit and how much to grind off to get the little monster sharp. Practise makes for perfect.
Mark
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