in the fin can. The one in the fin can will be responsible for apogee
deployment, and the one in the nose cone will handle main deployment.
-Jeff Lane of [Shock Wave Rocketry](http://hockwaverocketry.com/) expressed a
+Jeff Lane of [Shock Wave Rocketry](http://shockwaverocketry.com/) expressed a
willingness to fabricate a custom 98mm nose cone with the temperature sensors
embedded in the glass layers, as he is also interested in the data we hope to
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
-* 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
The OpenRocket design file is
[2YikStik.ork](/rockets/airframes/2YikStik/2YikStik.ork).
+### 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.
+
## Build
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... but
+I kept a [log](/rockets/airframes/2YikStik/buildlog) that may be of interest.
+
+[Photos](http://gallery.gag.com/rockets/2yikstik/)
+
## Publicity
## Flights
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 flew 2YikStik at [LDRS 30](http://ldrs30.org/) on Friday morning. The
+first couple seconds were glorious! Unfortunately, we hit a wind shear layer
+just as we were approaching mach, and the side pressure on the nose cone
+apparently snapped the coupler behind the nose bay, causing the remainder of
+the propellant to be expended sky-writing instead of going up. Way
+too exciting!
+
+The airframe didn't get going fast enough before the incident to log any
+interesting skin temperature data, but the sensor in contact with the motor
+casing showed the anticipated rise as the motor burned, so we believe the
+TeleScience boards were working fine.
+
+Jeff Lane took this [video](m1545.mov) of the flight.
+
+[YikStik3](../YikStik3/) will be our next attempt.