Do you guys sharpen your twist drills?

One thing I noticed with my drill doctor was that while the bevel was dead perfect, the "back edge" of the bevel did not have the proper relief. Once I got the bevel established, I took it to the belt grinder and put more relief on the trailing edge...night and day difference. Probably applied too much pressure and a worn diamond wheel. Now, since I taught myself how to manually sharpen, The only thing I use it for not is to establish a starting point from a broken bit.
 
A little update.

Played around with the Drill Doctor and found that if I change the alignment a little by twisting the chuck one slot to the left (+) I get a little better relief angle.



Although not sure I still get enough.



But they do cut pretty good so I might leave it at that.

Tried my hand some more at hand sharpening, especially larger drills. Looks ok from the top.



Not bad from the side but I still have to make it smoother, not so many facets. Plus better relief angle, it looks a bit off.



And although the drill cuts pretty good, I get this 5 sided hole which I guess has to do with the point not being on center (maybe???)



Once again, if you see anything you think I could do better, I'd love your advices.

Thanks
 
I've never used a drill doctor as I do all of mine by hand on the 2 x 72 but it looks from the picture that the grind is very uneven & coarse. The center of the sharpened bit appears to have a bit of a reverse relief.

Sharpening a drill bit takes a bit of practice to do free hand but I'm sure that you can get the feel for it. With the power off hold a new bit against your belt grinder until it touches all the way across the grind of the bit to get the feel for where you need to be as to angle & relief. I could show you quickly but it's a little hard to describe.

Gary
 
Too much relief will cause an oversize hole and rapid bit wear but too little relief will limit feed rates. The chisel angle and relief angle vary proportionately so determining the chisel angle is needed. Holding the cutting edges so they are aligned with 3 and 9 o'clock, while staring down at the tip the chisel angle should be at 1 or 1:30. If you set the bit in the chuck based on this angle the relief will be fine.
 
Patrice, how are you deciding that you are not getting enough relief angle? Those holes do not look good at all. If you get a drill gauge , you will be able to measure the length of edge and compare. If they are off center then the hole will no be sized properly. If you have ground a symmetrical bit, then your curls should be equal from both sides.

What do the holes look like from the dd sharpened drill?
 
Hey Patrice,

I have also sharpened by hand for years and can do a pretty good job of it on bits 3/16 and larger.

I got a drill doc a couple of years ago. Mine works very well.

I have a high quality set of HSS bits that I've had for 30 years.

If not for sharpening I would have gone though hundreds of dollar's worth of bits over the years.

It's like any other skill, be diligent you'll get it.

Greg
 
Gary, using the powered off grinder is a great idea. I might move to the KMG also. Been doing it on this small grinder and it feels a little “small”. Might see better and get a better feel on the KMG. I guess wheel size doesn’t matter that much does it?



John, proper pilot hole (the size of the web I think) is something I need to be more careful about.

Here is what Doc asked, two holes on the left are from the Drill Doctor sharpened bit with the modified indexing.



And the backside. Drill seems sharp so the crap might just be from the gummy mild steel I use.



And this is the protractor I use. As you can see there are markings that can help me measure if the grind is of equal length but I really should order a “real” sharpening gauge. :o



Greg, I've been using crappy twist drills up to now and I am thinking that it is time has come to invest in a good US made set. :thumbup:

Thanks again for all your help.
 
Pat- I think I agree with the feedback you've gotten on this page. Your hand sharpened bit looks to be at an awfully rough finish--- looks like there's a burr on the lip.

The facets will cause all kinds of issues. Are you resting your knuckles on the tool rest with the supporting hand? I can barely sharpen a bit without my supporting hand resting on the tool rest. It makes it so much easier to get a nice, smooth, facet-free grind.

I prefer a bit ground to a 135 degree lip angle. It won't penetrate quite as quickly as a 118 degree drill, but it's got a lot more beef supporting it.

IMHO you should hold off on buying a full set of twist drills, and just buy a handful of the most commonly used ones in your shop. At least for now. :)
 
I have used a Drill Doctor a lot. It's a plastic tool, and if you are the least bit "ham-handed" things will flex and you will get a poorly sharpened bit. Once you figure out just how much (little) force to use it will do a good job. But before I had a Drill Doctor I had a $15 jig that was mounted to the workbench next to the grinder and used the side of the grinding wheel to sharpen drill bits. It worked just as well as the Drill Doctor, it just took a bit longer. Now I sharpen drill bits on a Darex M5 which does a great job if adjusted correctly, but you have to sharpen a lot of drill bits to pay off the investment.
 
Got to spend a little more time on this.

Following your advice Nick I tried with my knuckles resting on the toolrest and it made a big difference.



Sorry for the blurry pic but the resulting hole (also using the proper sized pilot hole) is much better.



I'll get there. I think that I assumed that I would pick this up quicker but looks like any other skill, I am gonna have to spend the time needed to develop muscle memory. Thank you guys for the help.

Note: Nick, that is a good idea about buying only the most used drills. :thumbup: It's not like I have a machine shop and need all of them. I use maybe less than a dozen different sizes most of the time.
 
I don´t want to be a smart*ss but I found that I could buy a complete set of drill bits in a decent container for the same money as buying app. 1/3 of them as single bits.
I don´t know how it is for you guys but over here single drill bits are VERY expensive compared to a complete set.
Just my 2c :)
 
Small update.
There was a sale at a tool store (the only one) not too far from me. The sad part is that they just don't ell enough steel working tools to keep an inventory. Good thing is that they had a few things left and good deals. One of the only thing that was not on sale and the main reason I went was the Starrett drill sharpening gauge at 69.95$. I ask the gentleman if they had not forgotten to put the sale price on it and he said let me check in the computer. He came back and said, how does 9.99$ sound. :D



I know this won't magically make me good at sharpening twist drills but having the proper tools is always a good place to start.
 
Ehh... This all sounds pretty complex. Ever wish you could take shop over again in high school? I know I do.

I guess now is as good a time as any to start learning. I have a complete set of hss drills that my pop left me. Probably best not to trash them.

Good thread Patrice. :)

Oh, and nice buy. Nearly anything Starrett is worth a ten spot.
 
Patrice Lemée;13422348 said:
Small update.
There was a sale at a tool store (the only one) not too far from me. The sad part is that they just don't ell enough steel working tools to keep an inventory. Good thing is that they had a few things left and good deals. One of the only thing that was not on sale and the main reason I went was the Starrett drill sharpening gauge at 69.95$. I ask the gentleman if they had not forgotten to put the sale price on it and he said let me check in the computer. He came back and said, how does 9.99$ sound. :D

.
Click to expand...

I'm a little jealous of that deal, it never hurts to ask, but somehow I don't usually ask.
 
Strigamort said:
Ehh... This all sounds pretty complex. Ever wish you could take shop over again in high school? I know I do.

I guess now is as good a time as any to start learning. I have a complete set of hss drills that my pop left me. Probably best not to trash them.

Good thread Patrice. :)

Oh, and nice buy. Nearly anything Starrett is worth a ten spot.
Click to expand...

It's really not as complex as it seems. Just a twisting movement with the hand. Check the relief and centering, measure if you have a nice gauge. Done.

Don't usually have to look too far to find a cheap or damaged drill to practice on before you start on any with sentimental value.

Patrice, it looked like you were using a belt to sharpen in one pic, have you considered trying the disc grinder? You might even be able to reduce the chisel point with some careful work at the edge.
 
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