a few updates

[web/gag.com] / rockets / airframes / 2YikStik / index.mdwn

diff --git a/rockets/airframes/2YikStik/index.mdwn b/rockets/airframes/2YikStik/index.mdwn
index c1a85ae854b59ad550d5576f06dd9035cb72644e..ccfba26e5722dacfda80e57df2f8dfbfc53deca1 100644 (file)
--- a/rockets/airframes/2YikStik/index.mdwn
+++ b/rockets/airframes/2YikStik/index.mdwn
@@ -32,7 +32,7 @@ collect.
 * 98mm [Giant Leap](http://giantleaprocketry.com) Dynawind air frame
 * 75mm [PML](http://www.publicmissiles.com) phenolic motor mount
 * [Shock Wave Rocketry](http://shockwaverocketry.com/) fiberglass 98mm Von Karman 6:1 nose cone
 * 98mm [Giant Leap](http://giantleaprocketry.com) Dynawind air frame
 * 75mm [PML](http://www.publicmissiles.com) phenolic motor mount
 * [Shock Wave Rocketry](http://shockwaverocketry.com/) fiberglass 98mm Von Karman 6:1 nose cone

-* custom fins, using 1/8 inch birch plywood laminated with carbon fiber 
+* custom fins, using 6/16 inch birch plywood laminated with carbon fiber 

   and a fibreglass sanding veil
 * 3/8 inch birch plywood centering rings and bulkheads, CNC milled, the two 
   that hold the fins are double thickness (3/4 inch) and notched for perfect 
   and a fibreglass sanding veil
 * 3/8 inch birch plywood centering rings and bulkheads, CNC milled, the two 
   that hold the fins are double thickness (3/4 inch) and notched for perfect 


@@ -45,6 +45,57 @@ The OpenRocket design file is
 
 Parts gathered during October 2010.  Built mostly during April and May 2011.
 
 
 Parts gathered during October 2010.  Built mostly during April and May 2011.
 

+The nose cone was custom fabricated by Jeff Lane at 
+[Shockwave Rocketry](http://shockwaverocketry.com), with thermistors embedded.
+
+The fins are 3/16 inch birch ply, tapered on the leading and trailing edges,
+then covered with one layer of 5.7 oz 2x2 twill carbon fiber and a layer of
+6 oz glass as a sanding veil, all vacuum bagged with West Systems laminating
+epoxy using a kitchen food saver appliance.
+
+The airframe tubing is Giant Leap Rocketry 98mm Magnaframe-based Dynawind,
+except for a short section behind the nose cone that uses the older phenolic
+based Dynawind because of the slightly larger inside diameter being a better
+fit for the glass nose cone shoulder.  
+
+The tailcone is a no-longer-available Giant Leap 98-75mm Slimline tailcone.
+
+All rings and bulkheads were cut using a CNC milling machine from 3/8 inch
+birch plywood.  The fin forward and leading edge rings are made from 3/4 inch
+thick assemblies made by laminating two such rings with wood glue, to provide
+sufficient depth for milled fin slots.
+
+Assembly techniques were "nothing special" except for the electronics...
+
+[Build Photos](http://gallery.gag.com/rockets/2yikstik/)
+
+### Thermistors ###
+
+The temperature sensors chosen are 0.8 mm diameter glass bead NTC thermistors
+made by EPCOS, model B57540G0303F000.  These were chosen because of their
+small size, and turn out to have a very fast response time to changing
+temperatures. 
+
+The leads were extended with 30 gauge wire wrap wire using twisted pairs of
+black plus a color.  The colored lead was insulated from the bead back over
+the solder joint using 1/16 inch heat shrink tubing.  The epoxy used for the
+nose cone and fin was tested and confirmed to have essentially no 
+conductivity.
+
+### Electronics ###
+
+The airframe geometry led us to decide to build two electronics bays, one in
+the airframe immediately aft of the nose cone, and the other in the fin can.  
+Each bay holds a production
+[TeleMetrum](http://altusmetrum.org/TeleMetrum), a prototype companion 
+board called [TeleScience](http://altusmetrum.org/TeleScience), a 900 mAh
+LiPo battery, and a power switch.
+
+The TeleScience board supports connection of up to 12 NTC thermistors along
+with other capabilities.  
+
+Installing the electronics in the fin can bay was .. interesting.  More later.
+

 ## Publicity
 
 ## Flights
 ## Publicity
 
 ## Flights


@@ -52,5 +103,4 @@ Parts gathered during October 2010.  Built mostly during April and May 2011.
 The original objective of flying 2YikStik at NCR's Mile High Mayhem 2011 
 was not met due to weather conditions unfavorable for a high altitude launch.
 
 The original objective of flying 2YikStik at NCR's Mile High Mayhem 2011 
 was not met due to weather conditions unfavorable for a high altitude launch.
 

-While it's possible we might be able to attend another NCR launch this summer,
-at this point we likely won't fly 2YikStik until LDRS 30.
+We currently hope to fly 2YikStik at [LDRS 30](http://ldrs30.org/).