You can never have too many
micro turning tools!
Sharpening Overview: It's no secret that I'm a big fan of micro turning tools. They are my favorite tools to use when I need to add fine details to projects, or when working in very tight quarters. The overall lightweight of the tool and the small bevel allows you to produce very elegant and glassy smooth cuts, whilst delivering excellent tactile feedback through the handle. While you could always turn fine details with larger tools, they do not offer the same level of tactile feedback or ease of use when turning in tight quarters.
When I first opened my studio more than thirteen years ago, a five-piece Henry Taylor Micro Turning Tool Set was one of my first tool purchases. Through the years I have worn out a few sets, so I now keep several on hand with different grind profiles. These five-piece sets cost about $100.00 and include a 1/4" micro spindle gouge, a 3/16" micro spindle gouge, a 1/4" micro skew chisel, a 5/32" micro parting tool and a 1/4" micro round nose scraper.
The Disappearing Micro Turning Tool
If you have a slow speed or a high speed dry
grinder, your micro turning tools will last longer
using my protocol
My first set of micro tools was sharpened on a high-speed (3,600 RPM) dry grinder, using a 120-grit Norton Aluminum Oxide white wheel. I quickly found out that my micro turning tools disappeared rather quickly on the high-speed dry grinding wheel. Not to worry, I bought another set and I set about trying to find a way to make them last as long as possible. This would be no easy task as I was using them on a daily basis in my production turning studio.
All of my early experiments centered around how to increase the life expectancy of my micro turning tools when using my 6" no-name high speed dry grinder. Switching to a low speed dry grinder would have helped quite a bit, but there was no money in the budget at the time for another grinder, so I starting looking for ways to make my high speed grinder less aggressive.
I was already using a fine grit wheel (120-grit), so getting a finer wheel was not an option. The jig I was using made it easier to keep a light touch on the wheel during grinding, but my tools were still disappearing too fast. These tools were seeing brutally heavy usage every day, but I still wanted to get as many trips to the grinder as possible out of each and every tool.
Various jigs can be used with micro turning tools.
From left: Kelton, Tormek, Woodcut, Oneway
As time went on, I experimented with honing in between trips to the grinder. This helped a bit; it was still a challenge at times to hand hone an Irish grind on a 3/16" spindle gouge without rolling the edge. I also experimented with a flat Arkansas stone for a few months, but ultimately decided against this method as well. The cheapskate in me wanted an easy, foolproof and most of inexpensive way to squeeze more life out of each tool using the equipment I already had in the studio.
One day I was at the grinder working on several of my micro turning tools and after a few minutes, I switched the grinder off so I could go eat dinner. As I hit the switch, I noticed one of my 3/16" spindle gouges was still waiting to be sharpened in the jig. The grinder wheel was still spinning very fast, so as the wheel began to spin down, I decided to grind the gouge… It worked beautifully! In no time, the Irish grind was sharpened and I was finished.
My 6" high-speed grinder had very good bearings and it took quite a while for it to come to a stop once you switched it off. The next day, I used the same technique of turning off the grinder before sharpening my micro turning tools. As the wheel spun down the RPM's decreased, effectively turning my high-speed grinder into a "slow" speed grinder. I used this technique for quite some time as I kept refining the protocol to make it even more efficient.
Turn On - Turn Off
Using this new protocol my micro tools were lasting much longer now, even though they were seeing even heavier usage. This protocol served me well for quite some time and became the standard way I ground my micro turning tools. I eventually modified the protocol from a "turn off and sharpen" to a "turn on, turn off and sharpen" sequence, since the grinder was not always running when I needed to grind my tools.
Turn your grinder on and let
it begin to speed up for 1-2 seconds
Then, turn your grinder off
As the wheel begins to ramp down,
start grinding your micro turning tool
Sweeping the right side
of the spindle gouge
Sweeping the left side of the
spindle gouge completes the process
as the wheel continues to ramp down
If you leave you grinder on all day like some turners do and you have a high speed grinder, all you need to do is turn it off and as the wheel spins down and refresh the edges of your micro tools. This technique works very well on the slow speed grinders in my studio as well.
If you only turn your grinder on when you need to sharpen a tool, use the "turn on, turn off and sharpen" protocol to grind your micro tools and see what a difference it makes in their life expectancy. Your tools will last much longer and you'll get the same quality edge. That's what I call a win-win situation! Give it a try and see what you think.
Wet grinding systems like this Tormek T7
remove a minimal amount of metal with
each sharpening and will make your micro
tools last significantly longer
Another option for extending the life of your micro turning tools is to use a wet grinder, like the Tormek. When I first opened my studio I did not have a wet grinder, only a 6" no-name dry grinder. As time went on, I added a few 8" dry grinders and a Tormek wet grinder. The Tormek wet grinder is without a doubt a superior method to sharpen micro turning tools when compared to dry grinders.
The finer 220-grit wheels on the Tormek slow speed (90 RPM) wet grinder take off much less metal with each sharpening than a fine 120-grit dry wheel on a slow or high speed dry grinder. Tormek's 220-grit wheel can also be graded to perform like a 1000-grit wheel using the stone grader for an even finer edge. The gouge jig allows precise relocation and repeatability of the bevel on the stone, for fast and efficient edge renewal.
You can also hone the bevel edge on the leather wheel if desired, producing a mirror polished bevel edge, with no danger of roiling the edge. Tormek also offers Japanese water stones to fit some of their wet grinders, in an ultra fine 4000-grit. These Japanese stones will make your micro turning tools last even longer than their traditional green stone.
For more information on Tormek Wet grinders, look here.
If you want the best option for extending the life expectancy of your micro turning tools, a wet grinder like the Tormek is worth considering. If you prefer to use a dry grinder, give my turn on, turn off and sharpen trick a go and you'll find that it will greatly extend the life of your micro turning tools when sharpening on dry grinders. Either way, your tools will last longer, helping to keep some of your hard earned money in your pocket!
Safety Note: Always follow all manufacturers safety instructions before working with your lathe, or any of the tools or products you may use. If you are unsure about any operation, obtain competent professional instruction before proceeding. Use and wear all necessary safety devices during turning and observe safe woodturning practices to prevent accident or injury.
Steven D. Russell is a professional studio woodturner, teacher and writer. He has written numerous articles for international woodturning magazines, which have been published in more than 78 countries around the world. Steve has demonstrated in numerous cities across the United States. His studio, Eurowood Werks, specializes in bowls, platters and hollow forms with unique visual and tactile treatments.
Steve is also the current and founding President of the Lone Star Woodturners Association, Inc., an AAW member chapter. The LSWA is a 501(c)3 non-profit educational organization dedicated to teaching and demonstrating the art and craft of woodturning.
Steve is also a featured writer for the Guild of Master Craftsman's "Woodturning" magazine, published in London England. Woodturning magazine is the world's leading magazine for woodturners. Look for his articles covering technical topics, or project based articles in an upcoming issue.