Sometimes I need a special drill for a model project. For example, I need a drill with a 45 deg point. Another other project needed a flat bottom drill.
I am looking for recomendations on a drill sharpener that can grind these special points.
Any recomendations? I don't want to spend a forturne on something I will only use once a year.
chuck
A bench grinder. {LET THE "DRILL DOCTOR" GUYS FREAK!!!)
I have a Darex that works great for tips
Will it do flat bottom drills and 45 deg angles?
cs
Sorry, but I don't think I can grind a flat bottom drill or a 45 deg angel drill point with a bench grinder. cs
I don't have a link to an image handy, but there are several inexpensive variations of a sharpening fixture that mounts (to your bench with a single stud or bolt) perpendicular to the bench grinder wheel.
They tilt up/down for point angle, and swing in an arc for the relief angle.
These have been offered by Craftsman, General, and I believe the importers such as Homier have similar versions.
WB ..............
No matter how much they charge you once a year, it would be cheaper to go to a commercial tool & cutter grind shop and have your custom grinds done. Say you would have put $150 into a drill grinder. That money would bring you what, $3 in interest in a year? If you are going to have 2 drills sharpened special grind, that might cost you $5 a year. You can see it's a money-losing proposition to own a machine.
I own a Darex M3 with a Glendo mount for a 7" Baldor bench grinder. I can sharpen drills from about 1/8" up to 1-1/2", any angle I want. Those aren't cheap, nor are they current. Look for a lightly used M5 setup on ebay, or an M4 (same thing, just fewer included attachments). Sharp buying over time will net you one for $200-275. That will do a good job for you.
Other guys have written a lot about how to use a cheap General drill grinding jig. I've never looked because I figure all that writing is about a poorly designed tool or it wouldn't be needed.
You can actually sharpen larger drills freehand once you learn how. I don't think you can learn without a live teacher, though. Google on what teenut once wrote, it's the one where you indent the tip of your finger to act as a indexing stop or something.
GWE
Check out the Darex M3 or M5 systems.
My suggestions woud be:
Skip a drill grinder for once a year useage.
Invest in a good "opti-visor", a good work light, a good pedestal grinder with a suitable wheel, and a good protractor with a metal scale (with tenths graduations). Note that all of these can be used for other purposes. (protractor for angle, the metal scale for length of drill lips).
Truly, a couple hours spent mastering the techniques of grinding a drill point has it's own rewards. For example, get yourself a beatup drill bit and a scrap piece of metal. Oh yeah, a new drill also, from which you can visually compare physical features, and results of using same.
Regrind the old bit and try drilling a hole, noting perfomance. Chips from both lips of drill? Are they equal width/thickness? Force required to feed drill okay?
Just keep in mind a badly pointed drill can grab and do nasty things, so observe all appropriate safety precautions.
Grant sez: "> I own a Darex M3 with a Glendo mount for a 7" Baldor bench grinder.
I'm curious about how you sharpen the 1/1/2" drills. I have a Darex M3 and it came with a 1/16 to 1/2" chuck. Later I added the optional 1/2 to 3/4" chuck. Does Darex offer a chuck that goes to 1-1/2? How do you sharpen the drills over 3/4"?
Bob Swinney
Oh, you're almost certainly right, Bob! My bad .. I meant 3/4" not 1.5" .. mea gulpa
GWE
As they say, Grant, it takes an honest man . . . .
Best bet is to learn to hand grind the bits, it costs nothing to let a skill sit idle for a year and the few bits you ruin while you take the time to learn will cost far less. Yes there is a jig, gadget or fixture for those unwilling to learn a manual skill but they really are not needed.
With a bit of practice I'm sure you could.
Ned Simmons
Depends on how fussy you are. I've done both. You can also rough them on a bench grinder & fine tune them with a Dremel. The accuracy is only limited by your ability to determine where you need to remove metal and your patience. Some sort of template or jig could be used to check the angle, even a bevel protractor. An Optivisor helps.
Doug White
Bob,
What in the world is it about your newsreader? I frequently see you "reply" to something with nothing but quoted text, and then either follow up to that, or post again beside it a real answer. It happens occasionally with others, but it happens very frequently with you for whatever reason.
I find myself paging up and down in the reply looking for the added text, and then I go back to the top and see that it was you, so I go looking for another reply. :-)
Enjoy, DoN.
That depends -- I sometimes sharpen down to #70 drill bits, and would hate to try to do that by hand. For that, I have a drill grinder made by DuMore -- the makers of the toolpost grinders. They no longer make this, but it was avaialble with collets for all the way down to #70 bits. Unlike most collets, these don't actually grip the drill bit (which is gripped by a simple drill chuck), but rather stabilize the bit nearer to the point. It will handle up to 1/4" bits.
Enjoy, DoN.
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