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Recomendations for drill sharpening?

Kevin T

Stainless
Joined
Jan 26, 2019
With my lathe came about 2 dozen large (to me) MT3 shanked drill bits...1/2" to maybe 1 3/8" dia. They are mostly all dull and some chipped along the the bottom flutes. I would like to be able to use them from time to time but they need some attention. Have any of you guys used a company to do this that you can recommend? I think they would all go into a flat rate box so I don't have any problem sending them wherever if the price is right and the service is recommended. Also I am interested in what I can expect to pay if you have done this? Thanks for any heads up. I wasn't sure if I should ask this in the vintage section or not but will try here first since there are a lot of you guys with vintage stuff.
 
Most drill bits up to a 1/2" I sharpen myself, free hand on a grinder. The smallest bits I have more trouble with as my eyes are not as good, and there's never enough damned light :D.

Your mt3 stuff is bigger though, not sure if you want to give it a go or not. It takes a little trial and error till you see what cuts, but pretty doable.

End mills I'd have to send out, though I don't have a recommendation for that.
 
Most drill bits up to a 1/2" I sharpen myself, free hand on a grinder. The smallest bits I have more trouble with as my eyes are not as good, and there's never enough damned light :D.

Your mt3 stuff is bigger though, not sure if you want to give it a go or not. It takes a little trial and error till you see what cuts, but pretty doable.

End mills I'd have to send out, though I don't have a recommendation for that.

I know it "could" be done in my garage because the operation, especially once you are setup, is easy but because of this I was hoping it would be a pretty cheap thing to job out too.

Long story: I am pretty light on quality grinding stuff and since my shop is also where I store my precious toys I have tried to avoid getting more into grinding. The switch to insert tooling I made recently was expensive but I talked myself into it and I am running that way now.

Longer story: I tried to buy a Deckel grinder last year on ebay and was preparing to get serious with grinding but the transaction was soured when the sellers cousin told the seller that my winning bid was too low! The punk actually called FedEx and said he inadvertently shipped some toxic materials in the package without filling the paperwork that is required for airfreight to my home! So FedEx took the thing from Chicago to California and then shipped it back to Chicago and the seller cancelled the transaction! The fun part was when ebay told me that my $950 dollar transaction was not covered by buyer protection and I had to open a "case" three times to get them to look at my problem. In the end I had to show ebay where the people re-listed the item for sale and that was proof that they received the item. You see Fedex showed that the item was "delivered". The unfunny part was that the item was shown as delivered....BACK TO THE SELLER!
 
Please learn to do it by hand, it will really help you in many ways in the shop!

Maybe my "skill set" is not as good as others ("maybe" is being kind to myself:D) but I have found it near impossible to get both cutting lips spot on when hand sharpening, so each lip will cut evenly. Maybe my sharpening technique needs some help:o... Yes, the hand sharpened drills will CUT and it's better than trying to cut with a dull bit, but I find that I typically end up with a slightly larger hole. I would HUMBLY say if you are doing anything "precision" do get the drills professionally sharpened. I guess if one is going to use a boring bar AFTER drilling with a hand sharpened drill, then my point may be moot.
 
Maybe my "skill set" is not as good as others ("maybe" is being kind to myself:D) but I have found it near impossible to get both cutting lips spot on when hand sharpening, so each lip will cut evenly. Maybe my sharpening technique needs some help:o... Yes, the hand sharpened drills will CUT and it's better than trying to cut with a dull bit, but I find that I typically end up with a slightly larger hole. I would HUMBLY say if you are doing anything "precision" do get the drills professionally sharpened. I guess if one is going to use a boring bar AFTER drilling with a hand sharpened drill, then my point may be moot.

Yes I would like them to be used for precision purposes. I want to see twin streams of perfect chips roll off when I engage them. I can tell that they were "practiced" on already. My goal is to have a nice row of perfectly ready to use bits in front of me with beautiful, fresh cutting surfaces.
 
If you dont, already have a machine to sharpen big bits, they dull more rapid then a tin star, and you are stuck.
It does take time, and several stabs at it, but you will hit the sweet little move that no one can teach, and you will end up doing it with out much thought on all sizes of bits, and get the even chip flow-well pretty even enough.
The drill bit is by far the hardest working, and most abused tool, in the terrible donies world.... I am working on my BO with kerosene, but had to quit smoking.
 
Maybe my "skill set" is not as good as others ("maybe" is being kind to myself:D) but I have found it near impossible to get both cutting lips spot on when hand sharpening, so each lip will cut evenly. Maybe my sharpening technique needs some help:o... Yes, the hand sharpened drills will CUT and it's better than trying to cut with a dull bit, but I find that I typically end up with a slightly larger hole. I would HUMBLY say if you are doing anything "precision" do get the drills professionally sharpened. I guess if one is going to use a boring bar AFTER drilling with a hand sharpened drill, then my point may be moot.

+1 on this. I have occasionally sharpened bits by hand, but never for a precision hole. I'm a hobbyist in this field, so I don't see the need to develop this "skill set". Even if I wasn't a hobbyist, I would still demand professionally sharpened drill bits for any precision hole I was to create.
 
These work pretty well on bits from 1/4 through 3/4. Many will say never to use a diamond wheel as the steel will ruin the wheel. I've been using a flat sided diamond wheel on bits for years and it works just fine. You just have to go slowly to keep the heat down. I modified the adjustment end to use with longer shank drills like the MT2 bits for my lathe.

ebay around $30.drill.jpg
 
Put a steel plate on the wall behind the grinder. Weld a piece of round bar, maybe 6mm to the plate but put a sharp point on it and bend it at 90 degrees to the plate. Grind your drill to what you think is right. Take the drill and place it on the sharp point in the center drilled hole under the morse taper three shank and scribe a line on the plate . Rotate the drill 180 degrees and scribe another line. They should match. If not you know which edge needs to be trimmed up.

I find I always underestimate how much clearance I need to put on the bigger drills. Trial and error here gives you a drill that will drill real nice. Boring or reaming is for accurate holes,not drills.:)
 
Like said here before Drilling is for roughing a hole
No need for 2 perfect identical chips If I have 2 chips thats good enough for me
If you want a somewhat accurate hole predrill a 2-3 mm smaller hole and then drill for size Even a good hole with a way off ground drill then
A disadvantage on precion ground drills is that the drills start to bind on the sides with deaper holes That will ruiin your drill in a hurry
Especialy on a lathe you never drill to size but for a clearance hole only
Learn the trick of grinding drills once from somebody who knows how to and never look back
For bigger drills a drill gage is very usefull

Peter
 
My friend Schulze Belmyer at Riverview surplus has a few Atlas drill grinder attachments that mount to a standard bench grinder, I have two and would part with one, I can provide manual. I am not sure of the price but I suspect it is under $40. If anyone is interested the cost will be my cost from Schultze plus shipping plus a small Value basket from Culvers.

The grinder attachments rate to 1/2
 
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My friend Schulze Belnyer at Riverview surplus has a few Atlas drill grinder attachments that mount to a standard bench grinder, I have two and would part with one, I can provide manual. I am not sure of the price but I suspect it is under $40. If anyone is interested the cost will be my cost from Schultze plus shipping plus a small Valbasket from Culvers.

The grinder attachments rate to 1/2

I am interested in one of those if they are in decent shape! Thanks looks like a solid tool for smaller bits.
Let me know how to proceed and I'll do my part.
Kevin
 
Point of Diminished Returns?

Just my 2 cents.
Seems to me that there is a point of diminished return when it comes to professional drill bit sharpening.
I know there is when it comes to table saw blades and chain saws. It costs just as much to have them sharpened
as it does to purchase new...which is why I have so many of each.

Same is true (for me) when it comes to drill bits. On the small fractional stuff, I just toss and buy new.
And when I do, I always buy 2 or 3 extra. I inherited a set of drill bit organizer drawers in fractional, letter,
and number drill bits. (I haven't started metric). The number and letter drills are a bit spotty here and there,
but I keep the fractional well stocked; and usually with plain jobber drills. (Don't know that I believe all the
claims on "Titanium" stuff)

I also keep an index holder that I use for the fractional sizes, and it goes up to ½". I use these for general purpose
on the drill press and the lathe. I will only go to the grinder with a bit if I don't have a replacement ready to grab.
But yes, for the big MT drills, I will always send out for sharpening. (Although I can get by in a pinch, my drill bit
sharpening skills leave a lot to be desired!) :-)

I know this is pretty common knowledge, and correct me if I'm wrong, but my Dad taught me that when using a drill bit in
a press, the sharper of the two flutes will always "dominate" the cut, and can lead to a slightly curved hole. However,
when a bit is stationary and the work piece is turning (such as on a lathe), the bit is always being forced to center
of the workpiece regardless of flute sharpness, and therefore, it will not drill a curved hole. (In theory, of course).

So in regards to "precision sharpness", it makes a difference whether a bit is being used in a press or a lathe.
And I ALWAYS start with a hole drilled with a center bit usually followed with a good pilot hole..no ifs, ands, or buts.

But yeah, the big stuff (which I don't use very often) I will send out if need be.

PMc

PS: A GOOD drill bit sharpening device (in an enclosed sharpening station room) makes all the sense in the world.
I've just never seen one in action. What do the "pros" use?

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