Measuring Tools Overview: Woodturning is for the most part, a very fluid process. Many turners create designs on the fly and rarely if ever, work from pre-drawn plans. However, from time to time all of us need to be able to accurately measure our projects before or during turning. You may need to mark the major transitions on spindles, or perhaps you need to size a tenon, or a recess for an inlay, or the lid of a box.
Having the right tool on hand makes everything so much easier. No matter what you turn, a few basic measuring tools are always good to have on hand. If you enjoy creating your designs on paper first, or if you're working from a pre-drawn set of specs for a commission, you'll no doubt need a much more comprehensive set of measuring tools.
Through the years, I've accumulated various measuring tools and jigs in my studio that I use regularly for all sorts of measuring tasks both on and off the lathe. The following tools are the ones I use the most, and would not want to be without when designing projects, or whilst turning at the lathe.
Measuring Tools: Calipers
Essential calipers for woodturners (from left to right):
inside caliper, outside caliper, small and medium dividers
Calipers are one of the most ubiquitous tools in a woodturner's studio. Useful for both faceplate and spindle turning, you need a good set of calipers to measure tenons, check the size of recesses, measure lids for boxes, mark major transitions for spindles and a hundred other tasks.
Manual (upper) and electronic (lower) calipers are
great tools to use when precise measurements are
necessary and are accurate to 1/1000"
If you don't have any calipers now, look for a good 6" or 8" three piece set that contains a straight, inside and outside calipers. These will be necessary for a variety of projects around the lathe. If you are turning larger projects, look for longer versions of these tools for greater measuring capacity.
These calipers can easily measure the
thickness of bowl and hollow form walls
Measuring Tools: Angle Gauges
I use angle gauges frequently when setting up jigs on the lathe, or if I'm making critical beveled cuts with my bandsaw. The angle gauges sold for measuring the bevel angles on woodturning tools (like the Tormek Pro Angle Master) are always great to have on hand to check the accuracy of your woodturning tool bevel angles. Even if you don't own a Tormek, the Pro Angle master is a great tool to have next to your dry grinder to check your bevel angles.
The Tormek Pro Angle Master is a great jig to have by your grinder for checking bevel angles on your woodturning tools
These tools are used when I need to
determine or replicate specific angles
Measuring Tools: Centre Finders
If you turn spindles at all, a good centre finder helps you to measure the correct centre on your blank, reducing waste when roughing out your projects. If you turn pens, these tools can be a big help when working with some exotics, or alternative material pen blanks that are quite often very small, offering little room for error.
Centre finders are an easy way to accurately locate
the centre on spindles prior to mounting on the lathe
If you like to plan your projects on paper first, a good compass/divider set will be invaluable to you as you create your designs. I use a professional set that is almost 45 years old, but they still serve me well.
Dividers can also be used to check the distance between the transitions on your projects, when the lathe is off.
Measuring Tools: Profile Gauges
Metal or plastic profile gauges are a great way to check the profiles on your projects when turning. I use them frequently when doing spindle production runs as a quick way to check the profile before stopping to use my story stick, or custom cut profile gauge. If you need to make multiple copies of a project, this tool is very handy to have on hand.
If you're making multiple copies of a spindle, a profile jig
is a quick way to check the accuracy of your profile
Measuring Tools: Parallel Rulers
Parallel rulers allow you to draw accurate parallel lines when designing projects, or when measuring plans for a commission or a bid. These rulers are one of my prized possessions, as I used them when I was in the Navy Junior Reserve Officer Training Corps in high school, for homework assignments when I needed to draw navigational maps, or plan Naval convoy routes. Today, I use them for creating design layouts of complex projects, before giving it a go on the lathe.
Parallel rulers are a great tool to use when
designing woodturning projects in advance
Measuring Tools: Layout Templates
Layout templates are one of my favorite measuring tools in the studio. While there are numerous ways to draw a circle on a blank before cutting it, few offer the versatility of clear plastic layout templates. Since the template is clear (as opposed to plywood or cardboard disks), it's very easy to move the template around to find the best overall figure, or to eliminate defect areas on a blank.
This clear layout template is my favourite way for drawing
circles on bowl blanks prior to cutting on the bandsaw
When I started many years ago, I always wanted to turn the biggest project the blank would support. As I gained more experience, I preferred to turn the best project that each blank would support, regardless of the original size of the blank. While this results in some waste, the resulting blank offers the best and highest concentration of figure possible.
This is a personal decision of course, but I much prefer to turn the best section out of each blank these days, instead of simply turning the largest project possible. Layout templates allow me to make these cutting decisions quickly and accurately.
Measuring Tools: Circle Drawing Rulers
The Acu-Arc ruler allows you to draw accurate circles from 6.5" to 50"+ in diameter. This circle ruler is great for marking round circles on bowl or platter blanks, or when designing new projects on paper. While dividers or a compass might work well for drawing smaller circles, if you need to go big, this is a great tool for the job. These rulers offer a very compact and extremely accurate way to draw circles.
With the Acu-Arc ruler, you can draw
accurate circles from 6.5" to 50" or more
Measuring Tools: Flexible Curves
Flexible curves feature a series of thin plastic segments that slide against each other, allowing you to move the curve to experiment how various curves would look on your vessels.
You can also use them to check work in progress against a pre-determined curve that you want to achieve on your project. When used in this way, the flex-curve acts much like a template, or profile gauge and is very useful for not only designing projects, but also as a guide when finish turning a piece.
Whether or not you need one or more of these tools really depends on what you're turning and how you approach the turning of your projects. If you plan everything at the lathe as the wood is spinning, there is little need for drafting tools. You will still need things like calipers and normal rulers of course, as well as a good set of dividers.
When I first opened my studio, I did very little pre-planning of my projects. One of the things that appealed to me about woodturning was the ability to create projects on the fly. There is a certain freedom offered by the fluid and dynamic nature of free-style turning. However, I have returned to my love of drafting recently to assist me with the layout of complex projects and those that have not progressed beyond the conceptual stages.
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.