Lathes Part 4:

Building a Portable Spring Pole

 
While I generally find rotational lathes (such as flywheel and Great Wheel) easier to work on, the truth is that prior to the 17th century, most woodturning was done on springpole lathes. Their simplicity and low cost made them ideal for a trade that could little afford the more complex forms used mostly by metalworkers such as pewterers and bell founders.


In theory, a springpole is quite simple: all you need is something springy overhead, such as a tree branch. If a tree isn't conveniently located, you can approximate one by standing the branch up on a tripod of sticks. If you work indoors, you just attach said branch to the rafters of your shop and have at it.


Unfortunately, reality is not always as simple as theory.


In my case, I needed a springpole that would be portable, would work both indoors (with low ceilings) and out, and didn't involve toting about a whole forest of poles. A common configuration uses a sturdy forked tree branch to serve as a base, such as this one on display at the Globe Theatre in London:




A very workable design, but not very compact.


Unfortunately, many period illustrations of springpole lathes neglect to show the springpole itself, or at least what it is attached to. One that does is from the Mendel Housebook, which shows a springpole mounted on an upright post:




This gave me an idea for mounting the springpole on top of a post (a common 4x4). To make the post portable, it would need something to hold it upright. For that, I used an old section of cutoff walnut that a friend had given me after slabbing some boards. I cut a square mortise the size of the post, and keyed it with a wedge to make it snug.


For the springpole itself, I experimented with various woods and found that English Beech made a nice springy pole that didn't crack. Instead of a round pole, I used a long lath of beech about 1/3-inch thick and 2-inch wide, more like a leaf-spring than a pole. It gives a nice compromise, with enough stiffness for a crisp return, but not so stiff that it wears out my leg. It works nicely for spindle turning, though I suspect if I were bowl turning I would want something with a lot more strength.


I puzzled a bit over how to attach the springpole to the post. In the Mendel illustration, the pole is mortised through the top of the post. This seemed to me to make the top of the post very weak. I decided instead to use nails (two on each side), and a cage of wire. Okay, I admit it's not the most elegant or attractive solution, but it works well and allows me to change my mind after I've used it awhile, and also conveniently avoids the task of cutting a narrow mortise through a 4x4.