Why We Don’t Sharpen the Dividers
Posted on 27 July 2017
We’ve had a few comments about the fact that our improved-pattern dividers arrive unsharpened. And while we understand how that might cause a wrinkled brow or two, there are good reasons we ship them that way.
As I see it, there are two questions I need to answer to explain our rationale.
Question No. 1: Don’t All Other Dividers Come Sharp?
Most of you probably think that dividers are supposed to come sharp. Every other new pair of these tools comes with the same shape tips: a slightly fatter-than-average sewing needle.
My contention is that this has little to do with what is best for the woodworker and has everything to do with what’s easy to manufacture.
(I’ve prepared a detailed exposition on the Industrial Revolution’s shift from single-source to multiple-source craftsmanship – and why that led to dividers being abandoned, while rulers and other standardized measurement devices took over. I also discuss the shift to engineering and draftsman pattern-dividers, and away from the more robust versions previously found in most shops. And if you aren’t good girls and boys, I might still run through that entire rant on this blog.)
So for now, keep in mind that just because you’ve never seen dividers sharpened (or shipped unsharpened), that doesn’t necessarily mean that’s for your benefit. In my experience, it’s usually not.
Question No. 2: Wait. Is There More Than One Way to Sharpen Dividers?
We think there are plenty of ways to sharpen them. There is a huge range of possibilities in sharpening and tuning up dividers for different styles of work, different purposes and even different materials.
Let’s start by discussing divider schizophrenia. In most shops, dividers do the work of at least two instruments, dividers and compass. But dividers and compasses are not the same things.
Dividers are fundamentally a measurement tool. Don’t be fooled by the total absence of laser-etched graduations and a certificate of calibration – they were the fundamental measurement tools for builders right up until the Industrial Revolution made “interchangeable measurement” and “universal standards” critically important. Before that, the measurements that mattered were “internal” to a piece of furniture.
Rulers tell you how long something is compared to the National Inch Standard measure. Dividers don’t measure in relation to anything external. They’re just tell you how big one thing is compared to another. They are also spectacular at taking a measurement and dividing it into any reasonable number of parts. They’re much better, in fact, at both those tasks than rulers (even rulers with lasers and a built-in calculator). The downside is that you can’t just can’t tell your Southeast Asian production shop some arbitrary number of dividers steps via Skype and have them reproduce that measurement – that measurement is only good for as long as the dividers are set that way.
Compasses, on the other hand, aren’t for measuring at all (OK – oversimplification, but still mostly accurate). Compasses are for layout. A compass is for drawing circles and circular arcs. And that’s it.
In a shop, compasses don’t necessarily need a pencil on one end, though. Often, a scribing point is much better. Have you ever used your dividers to scribe a circle directly on a board? If not, give it a shot. Go ahead, I’ll wait.
Worked pretty well, no?
So here’s the first dip into alternate ideas for sharpening dividers: The tips for “walking off” distances are not necessarily the best tips for layout tasks. In fact, layout often works best with two different point-styles on the same pair of dividers.
In the next entry, I’ll discuss these different shapes for the points and how to create them.