X-Git-Url: https://git.gag.com/?a=blobdiff_plain;f=rockets%2Fairframes%2FRG-2%2Findex.mdwn;h=7290bd6eda14edf4b84afc2bf6495911b2bbccf7;hb=9c94d1d8ec07f20d995b6d06638236a46b82fdec;hp=212cbe14f7c3ddf55990467f1d87a2d7dedb2f4c;hpb=1b116422c87b65852cb182cd3e9e2e51ce3e2b64;p=web%2Fgag.com diff --git a/rockets/airframes/RG-2/index.mdwn b/rockets/airframes/RG-2/index.mdwn index 212cbe1..7290bd6 100644 --- a/rockets/airframes/RG-2/index.mdwn +++ b/rockets/airframes/RG-2/index.mdwn @@ -1,4 +1,4 @@ -# RG-1 +# RG-2 Robert's second full-custom rocket, with TeleMetrum electronic-deployment. @@ -7,8 +7,12 @@ 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 @@ -20,7 +24,46 @@ to fly one of those as the electronics system. 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