-# RG-1
+# RG-2
Robert's second full-custom rocket, with TeleMetrum electronic-deployment.
After the success of [RG-1](../RG-1), Robert decided it would be fun to build
a similar rocket in smaller diameter to try and get more than a mile above
ground on a G motor. The timing coincided with the first prototype builds of
-[TeleMetrum v0.2](http://altusmetrum.org/TeleMetrum), so naturally he wanted
-to fly one of those as the electronics system.
+[TeleMetrum v0.2](http://altusmetrum.org/TeleMetrum), so naturally he insisted
+on designing the rocket to fly one.
+
+Bdale and Keith both liked the design and wanted to join in the fun, so the
+plan is to be ready for a 3-way drag race on Cesaroni Pro29 full-G motors
+at [NCR](http://ncrocketry.org) Mile High Mayhem 2010.
## Design Details
that hold the fins are notched for perfect fin alignment.
* avionics bay design similar to Bdale's Trick-o-Treat
+[OpenRocket](http://openrocket.sourceforge.net/)
+[RG-2 Design File](./RG-2.ork)
+
## Build
+The build began on 21 March 2010, cutting all the phenolic and fin blanks for
+4 "kits" of parts.
+
+The first step was to CNC machine all the rings and bulkheads, then clean them
+up and fit them by sanding carefully.
+
+Next, we cut out the fins using our radial arm saw, and beveled them by hand
+using sandpaper flat on a table surface, hand-holding the fins at the desired
+bevel angle. Bdale cheated a bit on his fins using his Dremel with sanding
+drum to quickly remove most of the material then finishing up with sandpaper
+on the table... but that requires a very steady hand with a Dremel! We
+beveled the leading and trailing edges for looks and to reduce drag, but
+since these rockets won't break mach on a G the exact profile isn't critical.
+
+Assembly started by sanding the outside of the 29mm phenolic motor mount,
+and using a piece of angle to mark a reference line along the entire length
+of the mount. We use this reference line to get the first fin aligned
+perfectly. Next, we put the two fin-locking rings on the MMT along with the
+HAMR retainer body, and used the fins to work out from the aft of the MMT
+exactly where the fin-forward ring needed to be, marking the aft edge of this
+ring's position on the MMT. The fin forward ring's position is the critical
+part of building a fin can the way we do, so we take extra time to get this
+right.
+
+We then smeared 5-minute hobby epoxy around the MMT at this mark, and
+pushed the fin-forward
+ring into place from the aft end of the MMT, pushing an epoxy fillet on the
+ring's leading edge, and leaving the aft side of the ring fairly dry. We
+align the ring so that one of the locking tabs is positioned with one edge
+on the line up the MMT, so that when we put the first fin in place we can use
+that line to ensure it's straight along the MMT. And we're very careful to
+make sure the ring is "square" to the MMT. While we have some spare epoxy,
+we also smear the front of the MMT and slide on the zipperless fin can ring
+from the front. Then we let the epoxy cure. Do *not* glue the aft ring to
+the MMT yet! That comes much later.
+
## Flights
projects / web / gag.com / blobdiff