This is yet another customizable parametric fin alignment tool for building model rockets. This version is most useful for larger rockets, or those with through-the-tube mounted fins.

I (foolishly) designed this before searching Thingiverse, and I was shocked to see just how similar my design was to Justblair's (see http://www.thingiverse.com/thing:695599). Other than his being one piece and mine being multiple pieces, they are nearly the same, right down to the glue clearance arc. Great minds must truly think alike, huh? After seeing his, I initially wasn't going to post mine, but then I realized there are a few corner cases where mine may work better and it prints a bit faster.

I am building an Estes Big Daddy: This rocket has a 3" diameter body tube and fairly large through-the-tube fins. The large size makes it difficult for me to print Justblair's design (it doesn't quite fit on my printer), and actually I believe my multi-part design may be simpler for through-the-tube fins anyway. (On the other hand, his looks much more convenient and useful for fins that are glued directly to the outside of the rocket body, assuming the tool you need is small enough to fit on your printer bed).

Print at low infill (15%). You will need one copy for each fin on your rocket. Then use clothespins to hold it all together while the glue dries, as shown in the photos. It's a bit fiddly getting it all together -- make sure you have a minute or so to work before your glue dries.

Dimensions can be entered in mm or inches. If you choose inches, a scale of 25.4x will be applied to all axes, so that the output should work in most 3D printing software without the need to change anything. If for some reason you actually want inches (or yards, or whatever) in your output file, then just don't choose inches.

(NOTE: The customizer doesn't seem to like trailing zeros in parameters. Don't enter values like 1.230 -- use 1.23 instead. Weird.)

BTW, the values in the file are preset to work for the Estes Big Daddy.