Drill bit sharpening epiphany!

Patrice Lemée

Patrice Lemée

Joined
Aug 13, 2002
Messages
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I don't have anybody close to show me how to do it. Tried a little by hand on the side of a grinder a while ago and it did not work. I then bought a Drill Doctor, the 750 something, best model they have. Hit and miss with it and lately more miss than hit.

This afternoon I an trying to drill half inch holes in mild steel about 1/8 inch thick. Not working, I am polishing the hole. I spot my variable speed disk grinder from the corner of my eye and I think what the heck. Grab the half inch bit and with the speed turned down I grind what I think is about the right angle and after that the relief angle or whatever that is. I only have a vague idea of what it is suppose to look like and how to achieve it but can't hurt to try.

Surprise! It cuts like a brand new bit! :D Not sure if I can duplicate it but it is encouraging. I am so happy I had to share and strangely my wife did not see the big deal.:rolleyes: ;)

Patrice
 
Patrice Lemée;7587005 said:
I am so happy I had to share and strangely my wife did not see the big deal.:rolleyes: ;)

Patrice
Click to expand...

I share both your frustration on sharping a drill bit, and the amazement that the women in our lives can't see the importance of our discovery's in the shop.
 
I also succeeded a couple of times with the bigger drill bits, however I literally wiped off smaller ones by trying again and again...
Emre
 
I to have the drill doctor 750 something and it stays in the cabinet. The disk is my preferred method. I can touch up a bit in under 30 seconds only the larger bits. Tried sharpening the smaller bits but just can't get the angle to the dangle.
 
When I asked somebody to show me how to use his Drill Doctor, he told me it would be easier to teach me to do it freehand. So I took him up on it!

It's really not too tough when you just think about what you're trying to do. If you can grind a bevel on a blade, you can grind a bevel on a bit.
 
patrice, I do this now and then . I put a 220 belt on my grinder and put a bit in the drill and hold it up to the belt to see where i have to hold it and the I just turn on the drill at a slow speed. If you real steady it works fine.I just leave the grinder off.
vern
 
Patrice Lemée;7587005 said:
I am so happy I had to share and strangely my wife did not see the big deal.:rolleyes: ;)
Click to expand...

They just don't ever seem to "get it" do they? I get the classic "Oh!....that's nice" from mine.
 
v-6 said:
patrice, I do this now and then . I put a 220 belt on my grinder and put a bit in the drill and hold it up to the belt to see where i have to hold it and the I just turn on the drill at a slow speed. If you real steady it works fine.I just leave the grinder off.
vern
Click to expand...

I use the belt to grind my drills free hand, I wouldn't have thought you could get the right angles doing it your way.
Richard
Some tips. http://www.woodcraft.com/Articles/Articles.aspx?articleid=267

http://drillpointgrinders.com/drill_sharpening.htm
 
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I sharpen bits on the face of the wheel, not the side. Sharpening a bit is an aquired skill for a fact. I have both a 6" and an 8" bench grinder and it is easier for me to sharpen a bit on the 8". The hard part is getting each side the same so the bit doesn't wobble and drill an oversized hole. I've had the the "getting it sharp" part figured out for years. I still miss getting the point centered the first time every once in a while. :D
 
Be sure that you sharpen the two cutting faces symmetrically. You need the tip of the drill to be centered or your holes will come out over-sized. One reason to use a nice large pilot drill hole is to reduce that effect. With a small pilot hole and an off-centered drill bit your holes get too big. That can be a real problem if you need a tight fit. A drill sharpening gauge is a very good idea.
http://www.tpub.com/content/construction/14251/css/14251_319.htm
 
I worked in a tool and die shop for 14 years and sharpened all my own bits from 1/32" to 3" dia... I use my 2x72... it definately a handy skill. Especially when you visit your buddy's shop touch up his dull ones for him. Instant beer in hand.

Rick
 
The Drill Doctor is capable of good work, if you follow the instructions or watch the video. The important thing to remember is that it is made of plastic, it is necessary to have a gentle and consistent touch when rotating the bit in the sharpening port.
 
I didn't have any trouble freehand sharpening bits and I could make them cut, but when I started using my drill Dr. I found out how far off my freehand grinding was. The drill Dr. works great for me too. It's also great for split points.
 
I picked up a set of step drills on sale, they are TiN coated... hey, they were half price. They work great for drilling larger holes. I drilled five 3/4" holes in a propane tank in about 5 minutes or less with the big, fat bit.
 
Thanks Patrice,

I was shown how to hand-sharpen drill bits 10 years ago or so. I do it on the same grinder I make knives on. If you can make knives from scratch you can sharpen your own bits. I shudder with horror every time I hear "drill doctor"
I have sharpened 1 1/4" bits and down to .040"

Del
 
im slowly gettig the hang of at least gettign them workable again bhut i never had any one show me how
the little ones are a pain
 
Thanks for all the good tips. That should help me duplicate today's results. As far as the DD750 is concerned, I've read that it can be hit and miss from one machine to another. I think my problem lies with the indexing mechanism. Hopefully learning how to do it by hand will help me troubleshoot the DD. But again if I get the hang of hand grinding them I will probably leave it under the bench where it is now.

Thanks again.

Patrice
 
Hey guys I dont know how I missed this thread lol. I'm just learning how to sharpen drill bits. but a handy tool to help you get em centered right is a Drill sharpening guage. It helps you keep it centered by making sure the point measures the same on each side, and it also tells you if your at the proper 118º or 135º angle.

Drill-Gauge-1.jpg
 
I'm on my second drill doctor, and I'm NOT impressed... freehand sharpening is a useful and tricky skill.
 
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