Home Articles Page David@DavidReedSmith.com
You can download plans for my sharpening system from this page. My apologies for the size of the files.
I suggest you right click on the version you want and "save target as". The lower resolution versions have pictures that are 500 pixels wide, and are more than adequate for most uses.
In MS Word format, 4.9mb
In pdf format, 9.7mb
In MS Word format, lower resolution pictures 1.6mb
In pdf format, lower resolution pictures 7.8mb:
From the Introduction:
Sharper is better. And thatís pretty much sharper is better, Period. A sharper tool cuts with less effort, is easier to control, and leaves a surface that needs less sanding. The less pressure you have to use to cut the less chatter youíll get on the work and the less edge damaging heat youíll generate. The question isnít whether you need sharp tools but what is an unobtrusive way to get them. This article tells you how to make a sharpening system that has done that for me. It is inexpensive, quick to use, accurate, and capable of both extremely fine honing and moderately heavy grinding.
The system is based upon a cheap 8 inch Drill Press. The Drill Head is mounted upside down. The platform is mounted above it and supports the rest of the system. The drill press is used to drive a quick-change set of abrasive disks. Lubricant cooling is provided for all but touch up sharpening. Accuracy is insured by using the same jig for everything from the roughest grind to the finest hone. Three different jig supports are included. A multiple-angle platform sharpens roughing gouges (also works nicely on chisels and plane irons), skews, and scrapers. A V-Block Analog sharpens detail spindle and bowl gouges. A Straight Line Reference sharpens a variety of other tools.
It is possible to sharpen turning tools freehand and do it well. Once youíve learned to do it freehand you can sharpen with little interruption to your turning. It does, however, take a lot of practice, and most of us donít even practice turning enough. If you are a beginning turner you are further handicapped by not having enough experience to know whether youíve gotten it sharpened correctly or not.
Using a jig solves this problem as the jig enables you to sharpen correctly with much less practice. It can, however, trade one problem for another, because now you have the bother of finding the jig, resetting it correctly, attaching it to the tool, and adjusting the jig on the grinder. Iíve tried to avoid this problem using jigs that either donít need adjustment or are contained in the tool handle where they donít get lost.
Freehand Honing is also a skill that requires practice, if not as much practice as freehand sharpening. The Tormek system avoids this problem by using a relatively fine, re-gradable grinding wheel. The cost of this approach is that any heavy metal removal takes forever. Iíve avoided both of these problems by using the same jig for honing as grinding, and by allowing for practically instantaneous grit changes with a range from 36 to 3000.
I have had too many epiphanies (along the lines of ďSo THATĒS how itís supposed to cut!Ē) after first sharpening a tool with a jig to ever go back to freehand sharpening and honing.
There are differences between a flat and a concave bevel, but itís unlikely that either your tool or the wood will notice the difference. There MUST be a clearance angle for the tool to cut, so the only part of the bevel that rubs is the first tiny fraction of an inch or so where the wood deforms (Look at the photographs on pages 34 and 35 of Mike Darlowís Fundamentals of Woodturning). Rubbing the bevel is a metaphor. Just because it is a very useful metaphor that will help you keep your clearance angle small to maximize control and minimize surface defects doesnít mean it is literally true.
You, however, may notice the difference between a flat and concave bevel. The main advantage of a concave bevel is that it is easier to hone by hand, as less metal needs to be removed. If you do not hone you will slightly increase the minimum clearance angle attainable. If you do hone the wood sees a flat bevel in the only part of the tool in contact. If you do manage to bring the heel of the bevel in contact with the turning wood you will scar the surface by compression. This will be worse for a concave bevel than a flat bevel.
Jigs can be a great aid to better sharpening. Unfortunately the fuss of setting them up can also be a barrier to timely resharpening. First you have to find the jig, then reset it for the tool you want to sharpen (assuming you remember), adjust the jig on the tool and then adjust the jig to the grinder. You do not need to use the jigs in this article as other jigs such as the One-Way (whatís the name?) or Tormek jigs will work with a little modification for use with a flat grinding wheel. However I hope you will consider making my jigs for your tools. Most of my tools have the jig as part of the handle or stored in the handle. This makes them easy to find. They donít need adjustment to the tool as theyíre tool specific and only mount one way. This leaves only adjusting the jig to the grinder. Iíve found that the simpler it is to set up to sharpen the less likely I am to continue to work with a dulling tool.
Being able to quickly change abrasives can be very handy at times. Profiling a new tool on a grinder as slow as the Tormek is torture to my mind. Restoring a nicked edge is close. Bench grinders use coarse stones, so you must hone by hand or use a coarse edge. With my sharpening system you can change abrasives literally in seconds. A much wider range of grits is available as you can use any 8 inch abrasive disk. Iíve found 60, 120, 220 and a honing disk to be most useful, but you can use 36 or 3000 and every thing in between. For routine edge touch-ups I use one disk with 220 grit on the outer half and a honing compound impregnated surface on the inner half. This requires NO time for abrasive change.
You also donít have to worry about dishing the abrasive or dressing the abrasive when it gets clogged or dished. Just peel off the PSA abrasive disk and slap on a new one. I have no idea of the relative cost of a new grinding wheel versus the number of PSA disks that will do the equivalent amount of grinding, but even if the PSA disks are a little more, itís worth it to not have to dress them.
For each touch-ups with fine grit no cooling is needed. For heavier grinding I find lubricant cooling to be helpful. I donít have to worry about overheating the tool, and I donít have to breathe fine steel particles and silica dust. I started out using water, but adding a machinistís coolant additive reduces the problem of rust and seems to clog up the abrasive less.
Because the abrasive can easily be changed you can suit the degree of edge refinement to the task. If you are cutting green wood with edge destroying dirt in the bark you may want to use a moderately coarse abrasive for quick edge restoration. On the other hand if youíre working a dry hard to sand wood youíll want to take the time to work up to fine abrasive for the best surface off the tool. If for some reason your turning club has a cosmetic bevel contest, with a little extra time on a honing disk you can have a mirror bevel you can shave in or with.
The sharpening system and the plans are not copyrighted. You can copy and distribute the plans as you wish. If you come up with improvements to the system I hope you will feel morally bound to freely share them, but as I do not wish to copyright the plans I cannot require it.
There are some obvious safety considerations. I use an electric tool in a fashion it was not designed for. Adding liquid lubricant to a system without special electrics adds some shock hazard. The on-off switch ends up upside down. There is some potential for the abrasive disk holder to be launched Frisbee fashion. I do not feel unsafe using the tool, but certainly I would not suggest using the tool if your spouse is an OSHA inspector. You, however, may have different work habits and different concepts of risk, and will have to make your own determination and take responsibility for it.
It is possible to modify the plans to reduce the appearance of risk. You can relocate the on-off switch and shroud the motor to shield it from lubricant, or alternately forgo using lubricant. You could forgo some speed of abrasive change in exchange for a more secure disk attachment. If you do not wish to use the quick-change disks, simply buy extra extra Aluminum Grinding Disks from WoodCraft. Do not add setscrews on the rim. Adjust the fit of the ĹĒ drive shafts so that all are of exactly equal length. Put you abrasive disks directly on the commercial grinding disks and change the whole unit as needed. Making an extension for the chuck key will make change-over go more smoothly.