Sealey SMS01 Drill Bit Sharpener Grinding Attachment

Product Information

We often continue using dull tools longer than necessary, either because we haven’t noticed the signs of bluntness yet, or because we want to finish the job before stopping to sharpen. While the latter is understandable, it can be dangerous and places unnecessary strain on your tools and yourself. Additional features of these sharpening machines may include an automatic stop function that won’t let you cut too deep and damage the drill bit. Some models also come equipped with a grinder wheel. If you don’t have one already, we definitely recommend opting for these models.

For those who would like to build but don't want to reference the plan on Yahoo, here is some build info (see picture above). The Body is 2" long (1/2" or 3/8" OD), drilled to 0.243 and then reamed 0.250 half way through from each end. It is important to drill from both ends, centering carefully each time to ensure concentricity of the bore. When reaming the second half, run the reamer all the way through. A 0.035 wide groove, 0.030 deep is turned 0.865 from the lower end of the body. A 1/16" wide lengthwise slit is added beginning 0.6" from the lower end; slit length is about 0.6". My arbor is 1/4" drill rod 3" long but could be slightly longer if more then 5/8" drilling depth is desired. A JT-0 taper is added to the lower end of the arbor, cut by carefully setting the compound over. The top end of the arbor is center drilled 0.144, reaching to where the knurled handle will be, i.e. about 2.3". Cross drill slightly above this for a pin to hold the lower end of the spring - I used a 0.042 bit. Slit the arbor from 0.200 below the top end for the desired travel plus 0.65". Make a little top hat with an OD couple thou less than the OD of the body; turn the narrow part to fit into the body, slit the narrow section as shown in the picture and cross drill for a pin to hold the top end of the spring. There are a variety of drill bit sharpeners available on the market. If you’ve never used one before, the choice can be quite confusing. To save you hours of research, we’ve done the hard work for you and provided you with a rundown of the 7 best drill bit sharpeners available on the market today.Additionally, small drill bits tend to dull much faster, so you need to make sure that the sharpener can handle these as well. There’s nothing worse than a dull drill bit when you’re trying to finish a project! Durability 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. A professional would get more use out of the Drill Doctor DD750X, which has a little more versatility in the sharpening angles, accommodating almost any drill bit likely to be used. Drill Powered Drill Bit Sharpeners

Joseph Mazoff's article on drill point geometry suggests conical drill sharpening is easy to do but conical drills don't perform as well as faceted drills and that most drills sold in the US have excessive relief. The pictures are interesting and show some advanced geometries not often found in the typical home shop. More from Mazoff here. However, reduced relief for larger drills can easily be provided by adjusting the inexpensive sharpener differently than suggested in the directions or by adding a primary facet with the HoneDrill. Small drills can be ground at any desired relief angle(s) using the HoneDrill fixture and four facets can easily be produced if the user desires. Derek Brown's four facet sharpener produces fixed relief angles of 10° and 25° although the fixture is easily modified to produce any two selected relief angles - however, once selected they are fixed forever. Reduced relief is helpful in reducing chatter and hogging in, often a problem when using inexpensive drill presses because the minimum speed is higher than desirable for many drilling tasks. My simple prototype drill point splitter is shown at left. Point splitting is a special method of web thinning that extends the cutting lips almost to the center of the drill face. This improves cutting efficiency and reduces the thrust required while drilling. If you already have a bench grinder or are planning to get one like the DEWALT DW756, a drill bit sharpening jig like this one will help you accurately set the angle you need on your bits. It is essentially a specialized angle gauge that will work with most grinders and belt sanders. On the downside, a jig is not the only sharpening equipment you need and it can be costly to buy a grinder unless you have other tools you also need to sharpen.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. On the construction subject, this product seems and feels pretty tough. Plus, there are slots on the bottom that you can use to mount the machine to just about any workbench. This way, you'll be able to reduce vibrations and make this sharpener much more practical since you won't have to support its frame with your second hand.