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Spindles and turnings are found everywhere around us. You know, the ones found on parapets, balustrades, staircases and especially columns that stand outside, and support, many Greek Revival buildings. Sometimes I come across a turning I love and so I'll take a pic and obsess over it later. But now, with these little 3D printed jigs, I'll be far more likely to actually copy the turning so I can maybe try to understand why it's beautiful or make a physical copy at the lathe.
This technique for copying a turning isn't new. I learned it from Phil Lowe around 2005. I have copied dozens of turnings since then but my goal is to turn that to hundreds or thousands and document their origins and at least create a digital 3D drawing so I can enjoy them whenever my eyes need a vacation. This may sound like I'm going overboard but I can't tell you how many times I've missed an opportunity to retain spindles I find amazing.
These jigs mount the pattern material automatically aligning it with the centerline of the turning itself.
The jigs are secured to the turning with zip ties. The right size jig should be used so the zip ties have the best grip.
There is an elongated hole on the jig for a screw or bolt but I found using tape was just fine though I'd prefer double sided tape to blue tape. To make an accurate copy it may be necessary to use a level to plumb the pattern so that the edge you choose to square from is parallel with the centerline of the turning. I did it by eye in this case but wider turnings would amplify inaccuracy in this step.
I start by copying each horizontal that appears on the turning using a square. I'll do that all that up the pattern.
Onto each horizontal I mark the diameters as they relate to the centerline on the pattern. I divide the diameter by 2 and mark that length from the centerline on the pattern.
Once these parameters are copied to the pattern the next step is mostly visual and takes some practice. Drawing the shapes can be tricky and it may be helpful to know some of the basic shapes found on turnings: taper, fillet, cyma recta/reversa, scotia, thumbnail, urn, ovolo, ogee.... There are more but that's all I can think of at the moment. Do you know any?
The pattern needs more work and the lines refined but overall it's ready to be used to copy the turning at the lathe. So that's done. But follow on if you want to see how I create a digital 3D copy in Sketchup.
To create a digital drawing of a pattern I first take a photo of the pattern with a measuring tape visible. I take the photo from a distance to minimize distortion.