The Drill Doctor has been around for several years and claim over 3 million units sold so even before I got my hands on the unit I was thinking this product was more than just a gimmick and that it would work as advertised. The unit I had to test was the Drill Doctor DD750X which is the top of the line “professional” model that you can buy online for $139-179. The company that makes the Drill Doctor also makes the WorkSharp, which we also reviewed several weeks ago.  

Getting Started

The unit comes with a nice hard plastic case which stores all the components of the drill doctor. I would imagine most of the time the drill doctor will stay in the workshop and not be something you need to take to a jobsite or transport around but it’s still a nice feature. Getting started was fairly simple and self explanatory. On the top of the Drill Doctor is a bit alignment tools. You put the drill bit in the chuck, loosely and then place the chuck in the alignment device. Open the bit clamps push the bit in and close the clamps. The clamps align the drill bit perfectly to your specifications, however the only slot for the chuck that is marked in 118 degrees. If you need 135 or some other angle for the bit there are multiple slots however none are marked. In the book it says each slot is about 10 degrees (left +, right-) which means you couldn’t hit 135 exactly anyway with the alignment tool. Once you align the bit, tighten the chuck down and the bit should be set. On the actual grinding port there is another adjustment gauge and this time there are 118 and 135 degree marked settings. I set it to 118 because that was the only way I knew the alignment and grinding would be the same. At that point you simple put the bit in and turn clockwise. Always use even number of half-turns with light pressing. A rough idea for how many passes it will take would be: 3/32” 2-4 turns, 1/8” 4-6 turns, 3/8” 16-20 turns. It’ll depend on how worn out the bits are but if you check the bit every few full passes you will see how much old material is left.

Working All the Angles       

I had a bunch of old bits to sharpen of all sizes. These were all sizes, angles and different types of bits including a few carbide masonry bits. The instruction manual did have some really good information on identifying bits & angles, checking for wear problems and understanding what to look for to know your bit has been correctly sharpened (i.e. undersplit & oversplit). The 118 degree bits were first and went very smoothly. I tested out the MTO (Material Take Off) control on the alignment guide and could see the difference of how aggressive the grinding was; a feature only on the 750X model. I tried a ½” bit which told 20+ passes to get sharp, if you are planning to mainly do larger bits I would recommend switching the grinding wheel to the 100 grit (sold separately). When trying to sharpen the 135 degree bits I ran into the problem of not being able to align the bits exactly. When sharpening I could tell I was charging the angle of the bit, to what I’m sure but when it was all done they were sharp and worked good. It is also ok to make a 135 degree into a 118 degree bit it just takes a few extra grinds and you may need to take it out to realign once or twice. I tried this on two different sized bits and it worked great as well. When it comes to the carbide masonry bits… don’t rotate. Just “plunge” the bit in once on each side, I ruined the first bit and probably took some life off the grinding wheel. The second masonry bit I did worked much better.

Keep it Clean

As you sharpen your bits there is a lot of metal dust created. This will wear down the grinding wheel. Every few bits you should clean out some of the metal particles. Another option is hooking up a standard 1” vacuum to the grit tube which will such out the dust, extending the life of the grinding wheel. The grinding wheel itself should last for about 200 sharpenings. It is also recommended to turn the grinding wheel around after 100 sharpenings to maximize grinding ability. New wheels are $20, not bad for $.10 a sharpening.

Overall

I was very happy with the Drill Doctor overall with the one frustration that I couldn’t align the 135 degree bits exactly. For my purposes not a big deal but for some craftsman out there, that might be very particular about this, it could be an issue. I found the 135 degrees that were made into 118 degree bits worked just fine. Considering these were all pretty dull and within an hour there were dozens of sharp bits that worked great I would say overall this product works great.      

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