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Drill Doctor review - Confession time

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  • Drill Doctor review - Confession time

    This is embarrassing. I posted a review in good conscience generally praising the efficasy of the Drill Doctor 750 but panning its performance on smaller drills. I called the Drill Doctor people and was quickly connected with Denice their tech person. She walked me through several scenario none of which corrected the problem of unpredictably poor centering of small drills in their drill chuck/cam unit.

    Afterwards I carefully checked the assembly of the chuck until I discovered it was incorrectly assembled - twice. Once from the factory and once by me. There are shallow guides molded into the chuck barrel that the jaws have to engage in order to correctly align with the axis. This is tricky because the jaws are merely hardened sheet metal that dangle from a hairpin spring. The insertion of the jaws simultaneously in their guide slots has to be verified as it's assembled. A judicious nudge with a scribe helps the process. Once properly engaged the jaws stay put and accurately center.

    I appoligize to Professional Tool Manufacturing, makers of the Drill Doctor for incorrectly re-assembling their chuck and writing a review declaring a defiency that was not true. I also metaphorically kick their butts for not assembling their chuck correctly in the first place.

    So to amend my earilier review:

    Ensure the Drill Doctor chuck/cam units are correctly assembled so the jaws engage the slots in the thrust collar as well as the slots in the barrel. Mine were not and when I disassembled it for inspection and diagnosis I incorectly reassembled it in the same way it came from the factory. Without correct assembly it will not sharpen smaller drills so the point is correctly centered.

    The spring jaws inside the alignment port sometimes hang up. Be sure to wiggle the drill while it's a bit loose in the chuck so the spring jaws in the alignment port index the drill in time with the cam in the chuck. Only then do you snug up the chuck.

    Closely examine the clearance angle on smaller drills. I discovered on my unit the smaller the drills got the closer the as-ground clearance got to zero. While they cut they were slow to feed. I set the alignment adjustment lever to "+" to gain a bit more clearance and the drills cut better. This lever needs some intermediate positions.

    Follow these steps not mentioned in the manual and you'll sharpen drills down to the 3/32" minimum so the points are accurately centered.

    Sorry for my screw-up. I fully endorse the Drill Doctor as a drill sharpening asset for the home shop.

  • #2
    Thanks Forest,

    I've often thought about buying one of those, but I've always sharpened mine by eye. An endorsement from you means quite a lot to me. I'll put one on my list of must-haves. After that maybe an end mill sharpening fixture.



    • #3
      Forrest, you might consider adding this to your original posting so future searchers will find all of your applicable information in one place.
      Location: North Central Texas


      • #4
        Been there done that.

        It surely helps, but after a few dozen drills it is back to problems, I found out. I wouldn't rush to apologize too fast!
        CNC machines only go through the motions.

        Ideas expressed may be mine, or from anyone else in the universe.
        Not responsible for clerical errors. Or those made by lay people either.
        Number formats and units may be chosen at random depending on what day it is.
        I reserve the right to use a number system with any integer base without prior notice.
        Generalizations are understood to be "often" true, but not true in every case.


        • #5
          After the review I decided to break out my DD 750 again and give-er a test. I had not used it in three years cause I was not impressed with it's (my) ability to grind small bits.

          So I went at it again on a garbage HF black oxide bit. It was a new bit (should have taken a picture) and looked like they just drug it across a stone at whatever angle and said "it's shap". Well it wasn't so I reground it with the DD.

          It didnt take more than a minute. The bit is a 3/32". The shape is uniform front to back, the surface could be smoother. I kinda see lines which can be felt with my finger nail. A finer stone, (diamond is stone isn't it?) maybe.

          But overall it's heads and flutes above the original. Does it cut? Dunno yet, I wanted to attempt a picture with my cheapy camera first. JRouche