The inexpensive Pit Bull type drill sharpener (sold by Craftsman, General and Draper among others) is crudely adapted from a 1913 design by L.A. Van Royen. Van Royen's design was the basis for the Potts jig which was refined somewhat by Duplex in "Model Engineer". This sharpener produces a conical point and is adjustable to handle several common point angles as well as various relief angles. It may be possible to improve the point geometry produced by the inexpensive sharpeners with some relatively simple modifications.

Versatility – Drill bits require different angles for different purposes. Can your chosen sharpener create the right angle for your needs?

Recommendations

These specialized sharpeners are the easiest to use; once set up, they need minimal adjusting before they are ready to go. Their specialized function and ease of use make them a good option for beginners and professionals alike. If you don’t need the versatility to sharpen other tools, this is a good way to go.

Ron Behrmann is in South Africa (no Harbor Freight there) so he used a different grinder for power. Mostly aluminum, excellent machining especially the knurling. He used a different method to set the relief angles to discrete values, as pictured here.

Design Concept

Which brought up an issue I hadn't considered. This sharpener works well in my shop because I immediately sharpen any drill that seems dull in use, meaning I sharpen drills now and again rather than many at one time. With the 1/10 HP motor it takes 3-8 minutes to sharpen a drill, depending on size and condition. Not a problem the way I use the sharpener but when sharpening an index of 30 drills it takes hours. And most of this is grinding rather than setup - the little 1/10 HP motor slows down, limiting the grinding rate. Bottom Line: more power is needed to use this unit commercially. A grinding spindle and 1/4 HP motor in a setup similar to the Brooks might work well. Allied UK Delta_HTR is the most versatile machine on the list. Just like every other sharpener here, the model is able to work with any drill bit ranging from 3 to 13 millimetres (3/32 to 1/2 inches). At the same time, this machine will sharpen straight-edged knives scissors, plane irons, and many other blades between 6 and 51 millimetres. Why we like it: This sharpener is specialized for getting exactly the right angle on any drill bit you might own, no matter the size, material, or purpose.

Derek Toller drives both the 4 facet sharpener and a Harold Hall grinding rest from one grinder using a belt to drive the arbor. The grinding rest is fitted with Harold Hall's end mill sharpener so Derek is equipped to sharpen many tools with this setup. Grinding wheels are incredibly versatile and, as such, are a great addition to any workshop where you need to sharpen a variety of tools, not just drill bits. There is a learning curve to sharpening drill bits to the right angle without a jig or attachment, but it can be done. The movable part of my fence is HMWP, a plastic nearly as slippery and abrasion resistant as Teflon - it remains to be seen how well it holds up in practice with an abrasive stone rubbing on it; so far it seems OK.Paul Muensinger is a meticulous craftsman and a member of our local CTHSM group. Note the nifty drawer for collet storage. Paul included a picture of a drill he sharpened with SPA and split point. A general rule of thumb is, if you are wondering whether you should be wearing safety equipment, the answer is yes. Using a Bench Grinder

It is straightforward to fit the motion control to a specific motor and mounting plate. However, in replacing my original motor the minimum work approach was to place the new motor so the wheel has the same relation to the motion control as it had with the original motor. The 94071 wheel, even with the rubber feet removed, is higher than with my original motor. So, I mounted it using a scrap of angle iron to which the motor base sans feet was bolted. The angle iron was trimmed to fit the space available. Spacers were added under the angle to set the wheel height to match the original. I had to remove the holders for the tool rests and reverse the motor on its base so the wheel rotates CCW and the switch is accessible. At left is the traverse lever and link setup. Note the yellow HDPE used for bearings on the traverse - not a conventional approach. Dovetails or ball bearings would be typical but are considerably more difficult to build and need protection from grit. These plastic bearings are lightly loaded, have a very smooth feel, seem impervious to grit, and are cheap and easy to build - takes less than a half hour. The area where the plastic grips the table gets polished but doesn't seem to wear in normal use. We’ve also provided you with a very comprehensive buying guide, ensuring that you know exactly what to look for. You’ll be able to choose the model that’s ideal for your needs. We hope you find this guide useful and have saved some money by ensuring that you will hardly ever have to throw out your old bits! The sharpener will have no issues re-grinding chisels and plane blades up to 50-millimetre wide. You can adjust its bevel between 15 and 50 degrees, meaning you should be able to work with/access just about any sharp tool in your toolbox.This is also the best way to sharpen masonry drill bits that have a slightly different point shape to other drill bits. This drill-powered sharpener is a good option for those who don’t have a workshop, as well as for people who often work outside. It is portable and can be set up wherever you have your drill. As it’s essentially a mini grinder, you can use it to sharpen all standard drill bits to the correct angle, as well as knives and other small tools. Drill bits for different types of material typically require different cutting edges. A drill bit designed for wood is likely to require a sharper angle than one primarily used to drill into metal. Therefore, to sharpen bits effectively, you need a sharpener that you can adjust to suit these different angles. The Cost or Value for Money