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Thread: Sharpening Twist Drills

  1. #16
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    Nov 2006
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    This guy tested a lot of them and concluded the drill doctor was best despite the high price , but also thought an inexpensive jig you used on your bench grinder was pretty good even with the steep learning curve.

    My big takeaway was that NONE of them were able to sharpen bit to as good a level as his best factory bits ��

    https://youtu.be/pmr34sUFpK4

  2. #17
    The sharpener is correct about sharpening cost verses buying new. I know for a fact that it cost more to re-sharpen a 1/2 inch high speed end mill that it costs to buy a new one. I talked to a guy at work Friday and he showed me a part it took him 23 seconds to make so as long as there was a bar to make parts from they took 23 seconds or every 23 seconds a part came out. I work in the tool room and and I estimate that it would take me about 15 minutes to make the part manually. Manual is not cost effective.

    So cost for new drill bit verses cost to re-sharpen manually is the deciding factor. What he is saying is that if his cost to re-sharpen is 3 dollars and if the drill bit costs 1 dollar new then it is a no brainer.

    I was also an instructor in the tool and die program at the local community college and I saw a student take a brand new 9/16 drill bit and he ground it down so it was of no farther use. Part of the program was to learn how to sharpen a drill bit by hand. He never passed that portion. so not all hands are equal. In other not everyone can sharpen a twist drill by hand.

    At 76 I can sharpen anything 3/8th or over by hand and either at work or in my shop I have a bench grinder no more than 10 feet away. I have to pay close attention down to a 1/4 inch, smaller than that I can no longer see the wheel or feel the drill bit hit the grinding wheel.

    In my shop at home I use a drill doctor to re-sharpen drills under 1 /2 inch. The drill doctor was a gift and to me well worth every penny. Big drills sharpened by machine need sharpening less often that than hand sharpening and when it comes to small drills , dull drills also brake more readily than sharp drill bits. Now at home, I have no sharpening cost involved, only time verses out of pocket cost for a new drill bit, not to mention travel costs to the hardware store to get a new one. So if on a fixed income, re-sharpening is the less expensive option.

    The big problem is people do not actually read instructions and they over tighten the collet and if that is done then the drill bit will not cut period and then it is a waist of time to use it.
    Last edited by Tom Bussey; 04-24-2022 at 3:50 PM.
    Tom

  3. #18
    Quote Originally Posted by Ron Selzer View Post
    bought into the hype and bought a drill Doctor 750? years back complete with setup for left handed bits
    ruined every bit that has been tried in it, needs thrown in the trash. spent too much money to do that
    it sits on the shelf to remind me not to make that mistake again
    Well that's really a bummer, isn't it? I'm sorry to hear it. There must be some difference between the 500X I have and the 750 model. As long as I follow the directions, the 500 works very well for me.
    "All that is necessary for the triumph of evil is that good men do nothing."

    “If you want to know what a man's like, take a good look at how he treats his inferiors, not his equals.”

  4. #19
    As a follow up to my initial post, Amazon just delivered the Drill Doctor 750. It works perfectly. Although it wasn't cheap and it would have taken the purchase of a lot of new bits to break even, the fact is it's fast, does a good job, and for me, the idea of just throwing away a dull bit and buying new seems too wasteful when that bit is perfectly serviceable.

  5. #20
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    Quote Originally Posted by Ron Selzer View Post
    bought into the hype and bought a drill Doctor 750? years back complete with setup for left handed bits
    ruined every bit that has been tried in it, needs thrown in the trash. spent too much money to do that
    it sits on the shelf to remind me not to make that mistake again
    I've been using a DD 750 since not long after they came out; every single time it has produced unsatisfactory results has been traced back to operator error...

  6. #21
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    Feb 2004
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    Perth, Australia
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    I've been using a Drill Doctor 500X for about 10 years. Replaced a (worn) diamond wheel once. It does need to be used correctly. I've had sterling service from it all this years. I'd purchase another if needed.

    Regards from Perth

    Derek

  7. #22
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    Mar 2016
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    Millstone, NJ
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    1,590
    I have a drill doctor its probably 20 years old or more and has never been opened. I gotta do some more drilling I guess

  8. #23
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    Nov 2012
    Location
    Escanaba, Michigan
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    I purchased the DD 250 when they first came out years ago. I'm sure have paid for it several times. I must have sharpened a couple of hundred bits without replacing the stone. It is slow but, does the job. The stone needs replacing but, instead of putting on a new stone, I would like to upgrade. Does anyone have any experience with the DD750X, or another one? Reviews I seen look good. Any comments?

  9. #24
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    Gary, as far as I am aware, the only difference between the 500X and the 750X is that the latter goes up to a 3/4" bit, while the 500X goes up to a 1/2" bit. I never use a larger twist bit than 1/2" so the 500X was the one I purchased.

    Regards from Perth

    Derek

  10. #25
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    Nov 2006
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    Atlanta
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    Quote Originally Posted by Gary Thinglum View Post
    I purchased the DD 250 when they first came out years ago. I'm sure have paid for it several times. I must have sharpened a couple of hundred bits without replacing the stone. It is slow but, does the job. The stone needs replacing but, instead of putting on a new stone, I would like to upgrade. Does anyone have any experience with the DD750X, or another one? Reviews I seen look good. Any comments?

    What would you like to know ?

    I can't see the $110+ upgrade cost over a new diamond wheel being a good value. The main upgrade is the ability to do a wider range of point angles and split points on the 750. Guessing you haven't missed those features ?

  11. #26
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    Grandpa taught me to sharpen them at the wheel grinder but for nearly 20 years I have been using a Drill Doctor with good success. Quick, pretty fool proof, and about $100 today.
    "A hen is only an egg's way of making another egg".


    – Samuel Butler

  12. #27
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    Sep 2016
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    Modesto, CA, USA
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    The general hardware jig works okay for larger then 1/4" or so. I often see them at yard sales. $23 at amazon or Hoe depot
    Bill D

    https://www.amazon.com/General-Tools...38090210&psc=1
    Attached Images Attached Images
    Last edited by Bill Dufour; 04-27-2022 at 10:57 AM.

  13. #28
    Join Date
    Nov 2012
    Location
    Escanaba, Michigan
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    I have many old cement bits 1/8" to 1/2" which need to be sharpened. Has anyone used the 250 to sharpen them? As far as split point, I have very few.
    With the need to replace the grinding wheel on my 250, I think it is time to upgrade to a newer version of the Drill Doctor, or another sharpener.
    I agree with Dave the $110 upgrade over a new diamond wheel is a good value.
    Thanks guys, for your imput.
    Last edited by Gary Thinglum; 04-27-2022 at 7:25 AM.

  14. #29
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    Sep 2016
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    Modesto, CA, USA
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    I wonder if a regular drill sharpener can sharpen a cement bit or not? They normally have a lot of negative rake. Something wood or metal cutting bits do not use.
    Bill D

  15. #30
    I sharpen by hand, have a general for over 40 years and still not tried it. I dont want to rush into things.

    Have done concrete bits past and they work great other than I make them too sharp. You just need a green wheel. Freshly sharpened they were night and day just like high speed steel ones.

    for high speed steel if its super critical that is that you cant be a few thou over you wont want to hand sharpen.

    I was at a customers and went out to the car and my passenger window was smashed out, console rifled and broken. Did 10 other cars same time nice sunny afternoon. Auto glass place found a window for a 92 which was good and while there door apart and very experienced guy was drilling my door he was getting no where. He had to take an important call in the office and I asked if I could sharpen the drill bit. He said yes, he was a while so I took any bit I found and did a gaggle of them. When he started working again it was pretty much me being offered a job there.

    Dull tools are crap. sharpening a drill bit is simple if not perfect is needed. Having a gizmo is fine and good for a shop, on site you will be a victim. 80 percent or more freehand is way better than a dull bit.

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