Stand In, Stand Out

*WARNING - technical chair nerdery ahead*

 I think if you were to ask me to demonstrate the process that I learned in 2008 for undercarriage joinery, two things would happen. First, I would probably take a deep breath, and explain that reaching back in my frayed memory was not going to get us closer to that explanation. Second, I would proceed to lay out how using numbers and math and protractors and strings and averages and mirrors and judgement was frustrating; how none of it seemed to consistently add up to results that could be relied on. It always felt like some amount of luck was involved. I know that was operator error, but I could never pin down the variable that would hang me up. Like the staircases of Hogwarts, the culprit seemed to shift with each chair.

 For a time, I utilized a system developed by Pete Galbert which worked quite well. It removed numbers and math from the system, and was a huge step in the right direction for me and likely countless others. There were still mirrors and applied planes and plenty of places for me to screw it up. At this point, I consider it a good system to be aware of. It has applications that crop up from time to time; situations that require a fabricated reference that can be relied on to make an accurate mortise. 

 Fast forward to 2019. I flew to Tennessee to build a Birdcage side chair with Curtis Buchanan, who had sent a customer to me. The fledgling version of direct drilling he was using at the time was something he and Elia Bizzarri had worked out, and it worked pretty well, even if elements of the process remained ripe for development. The use of a 1/2" drill extension was there, as well as the propping up of the extension at a certain height in order to mimic the axis of the stretcher. It was **almost there** but it still felt like it could be made to be more consistent and repeatable. As I was still in the shadows trying to get up the confidence to teach my first student(s), I needed to know that I could make the process dependable.

​ The Stand-Out jig is a direct descendant of early, clunky attempts to mimic some of what Curtis was doing. One thing I knew I wanted to do was to take the plane of the worksurface out of the equation. With the seat propped up to allow leg tenons to pass through and be proud, using the benchtop as a reference to set the height of the contraption never seemed accurate enough.

 Thinking about how I had seen some chairs with through-mortises for stretchers, and how that was really ideal in terms of really nailing the angle of the mortise, I have landed on a couple of fixtures that really work well, and sometimes work well in conjunction. 

 To background the thinking behind the way these fixtures really work, let's start with what we are trying to accomplish when we bore a mortise in a leg to accept a stretcher, or in a back post to accept an arm. In order that the mortise "points" in exactly the right direction, in the case of a stretcher with coaxial tenons (not crinoline; more on that in a bit if I remember to cover them here) that means it needs to "point" directly at what I call the "origin" of the axis. This requires three bits of information about the location of the origin: 1) The distance from the seat (up/down), 2) The angle of the axis with relation to the origin and the mortise location (left/right), and 3) The distance from the origin to the mortise being bored (in/out) which is especially important whenever the stretcher isn't meant to run parallel to the bottom of the seat. This last one can be the result of design, or errors in reaming or measuring the depth of legs into the seat.
 
 Once those three elements are identified, a jig like the ones shown here will help hold a 1/2" drill extension in the right axis. The StandIn jig replaces the leg that hosts the axis origin, and is set to a height that mimics the origin mortise height, with respect to the target mortise. The StandOut jig can be used for all the situations that the StandIn jig can be used, and then some. I still use both and teach with both because the StandIn is easier to control when the mortises are for a leg-to-leg stretcher. 

 Finally, my reasoning for drawing up these jigs has to do with my sensibilities. If I have the tools and skills to create something, it is just in my nature to build it rather than buy it. For a fraction of the cost of commercially available jigs, I can make as many as I need, with no hesitation to modify them on the fly. This, and the understanding of exactly what they are trying to help me accomplish and how, is a very liberating feeling. While other jigs are on the market, they are either too rich for my blood, or too polished to feel like I have the freedom to destroy one if I have to modify it to fit my circumstances. These plans I am offering are geared towards those folks that feel similarly, but maybe don't know where to start fabricating a simple setup.
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If you made it this far, you can shop jig plans by clicking here and from now through 10/31 you can apply the code TRICKORTREAT25 at checkout for 25% off.

​Happy making!