I've never liked the Estes Fin Alignment jig (even though they seem to be much sought after on eBay!) because, like Craig, I've found them finicky and somewhat imprecise; and being vertical, I don't like the potential for glue runs and sags. For a number of years, I've been using the tried & true matte board method. I've been picking up 8"x10" and 11"x14" matte boards at Michael's (in their framing department - you can usually get leftovers on the cheap). I've made up a family of templates (eg: BT-60/3 fin/3/32"; BT-60/4 fin/1/8"; etc, etc) that I use to hold the rocket and fins in a horizontal position (this by itself is not a new idea).

I layout the template as precisely as I can with compass and straight edge; I cut out all three (or four) fins, and then chamfer the points where the fin cutouts interface with the body tube (this allows the template to slide over the assembly without interfering with any glue alongside the fin joint). It's a method that's worked very well over the years and usually provides me with very precisely aligned, equally spaced fins. Since I like to surface my fins with tissue and dope before I glue them to the airframe, I find that the fin slots in the template have to be just a slight tad over-size so that the template will slide on without any binding.

I said all of that to say this: it would seem to me that Carl could generate an extremely accurate and comparatively inexpensive family of fin alignment templates with his laser cutter; with a bit of ingenuity, these could be setup on a horizontal bed with sliders, making the whole fin alignment process very fast and accurate; being horizontal makes it much easier to manage the glue (of whatever type one chooses to use). This setup allows the modeler to tailor his alignment jig to his liking (more or less sophistication), while keeping the whole thing inexepensive.

I'll offer up a couple of photos of my usual setup once I manage to get home to my shop.

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John
YORF #003
SAM #004