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+# 8" V-2
+
+## Motivation
+
+The [V-2](https://en.wikipedia.org/wiki/V-2_rocket) has a significant place
+in the history of rockets, and Bdale always thought it would be cool to build
+and fly a model of one.  After learning how to make APCP research motors and
+experimenting with Everclear (which has visible flame characteristics 
+reminiscent of the LOX and ethanol fuel used in the original V-2) the 
+idea became even more appealing.
+
+And then, [Composite Warehouse](http://compositewarehouse.com/) put their
+[8 inch V-2 kit](https://www.compositewarehouse.com/index.php?route=product/product&path=18_70&product_id=158)
+on sale during their Black Friday sale in 2020... and it was just impossible
+to resist buying one!
+
+## Design Details
+
+This 8-inch diameter kit is all filament-wound fiberglass, with an 
+aluminum-tipped nose cone and 98mm motor mount.  A short coupler section is
+provided to attach the pre-slotted tail transition section to the main 
+airframe tube, and a longer coupler section is provided to double as the 
+nose cone attachment and electronics bay.  Beautiful, thick, stepped glass
+bulk plates with central 1/4-inch holes were included to enclose this bay.
+
+When the kit finally arrived in mid February 2021, the parts all seemed to be
+of outstanding quality, and the coupler sections in particular showed up in
+thick-wall glass that seems really robust.  An hour or so of fun involving
+a bathtub, a couple shop towels, warm water, and dish soap cleaned everything
+up and eliminated the residual fiberglass dust on all the parts in the kit.
+
+Further examination showed that there was one minor problem.  The aft 
+centering ring's inside diameter was fine, but the outside diameter was 
+smaller than the opening at the aft end of the fin section.  It wasn't a
+grossly un-usable part, and the gap could have been addressed by using some 
+small balsa shims to center the ring in the opening and sufficient epoxy with
+fiber filler to close the gap.  But, since a CNC router was available, the
+decision to fabricate a custom replacement aft ring with precisely positioned
+mounting holes for an 
+[Aeropack 98mm retainer](https://aeropack.net/motorretainers.asp)
+was easy to make.  The ring was cut from 1/2-inch birch plywood, stepped with
+about a 1/8" lip to the outside diameter of the glass, and 12 holes the 
+correct size to directly tap for a #8 screw thread.  The point of the lip 
+was to make assembly easy.  With the machined lip, the ring could be epoxied
+in place by itself but still assuring axial alignment.  The part was designed
+in [FreeCAD](https://www.freecadweb.org/) and cut on Bdale's 
+[Probotix](https://www.probotix.com/) Comet CNC router.
+
+## Design / Simulation File
+
+## Construction Log
+
+2020.11.22
+Kit ordered during Black Friday kit-buying spree.
+
+2021.02.17
+Kit arrived!  Fun in the tub cleaning up all the kit parts.  Dry fit various 
+bits to get a feel for how it should all go together.  Discovered aft 
+centering ring OD too small, reported to kit seller not asking them to take
+any action since I want to make a custom replacement anyway.
+
+2021.02.19
+Built up an [OpenRocket](http://openrocket.info/) model of the airframe, 
+except that using the latest released version, 15.03, it's not possible to 
+model the fins correctly.  The fundamental issue is that this version of
+OpenRocket doesn't support fins on transition sections.  Several work-arounds
+were explored, but the net effect is that Bdale needs to package a fresher
+version of OpenRocket for [Debian](https://debian.org) despite the lack of
+a new upstream release, since it appears this deficiency got addressed sometime
+since the 15.03 release.
+
+2021.02.21
+Designed and machined replacement aft ring, located the unused 98mm Aeropack
+retainer already on hand.
+
+## Photos
+
+## Flight Log
+