5 This is a "replacement" for Bdale's first L3 certification airframe,
6 [YikStik](../YikStik), which was mostly lost. The name was suggested by
7 Bdale's wife Karen to imply that it's in homage "to YikStik". The project
8 sat as just a simulation file for a long time, until Ed Shibadeh from
9 [Giant Leap](http://www.giantleaprocketry.com/) admitted at Airfest 16 that
10 he had one last 98-75mm Slimline Tail Cone in his personal collection that
11 he would be willing to let Bdale have. It's silly how much the little things
12 matter sometimes! The tailcone wasn't even part of the early YikStik design,
13 but once it was added it somehow became an important element of the overall
14 design that Bdale wasn't willing to do without on this project...
16 Meanwhile, Robert became interested in measuring the temperature of a nose
17 cone and a fin on a rocket at speeds above Mach. This led Bdale to design
18 a [TeleMetrum](http://altusmetrum.org/TeleMetrum) companion board called
19 [TeleScience](http://altusmetrum.org/TeleScience) capable of hosting up to
20 12 NTC thermistors for temperature data collection. The plan is to fly two
21 TeleMetrum+TeleScience setups, one mounted in the nose cone and one mounted
22 in the fin can. The one in the fin can will be responsible for apogee
23 deployment, and the one in the nose cone will handle main deployment.
25 Jeff Lane of [Shock Wave Rocketry](http://shockwaverocketry.com/) expressed a
26 willingness to fabricate a custom 98mm nose cone with the temperature sensors
27 embedded in the glass layers, as he is also interested in the data we hope to
32 * 98mm [Giant Leap](http://giantleaprocketry.com) Dynawind air frame
33 * 75mm [PML](http://www.publicmissiles.com) phenolic motor mount
34 * [Shock Wave Rocketry](http://shockwaverocketry.com/) fiberglass 98mm Von Karman 6:1 nose cone
35 * custom fins, using 6/16 inch birch plywood laminated with carbon fiber
36 and a fibreglass sanding veil
37 * 3/8 inch birch plywood centering rings and bulkheads, CNC milled, the two
38 that hold the fins are double thickness (3/4 inch) and notched for perfect
41 The OpenRocket design file is
42 [2YikStik.ork](/rockets/airframes/2YikStik/2YikStik.ork).
46 The temperature sensors chosen are 0.8 mm diameter glass bead NTC thermistors
47 made by EPCOS, model B57540G0303F000. These were chosen because of their
48 small size, and turn out to have a very fast response time to changing
51 The leads were extended with 30 gauge wire wrap wire using twisted pairs of
52 black plus a color. The colored lead was insulated from the bead back over
53 the solder joint using 1/16 inch heat shrink tubing. The epoxy used for the
54 nose cone and fin was tested and confirmed to have essentially no
59 The airframe geometry led us to decide to build two electronics bays, one in
60 the airframe immediately aft of the nose cone, and the other in the fin can.
61 Each bay holds a production
62 [TeleMetrum](http://altusmetrum.org/TeleMetrum), a prototype companion
63 board called [TeleScience](http://altusmetrum.org/TeleScience), a 900 mAh
64 LiPo battery, and a power switch.
66 The TeleScience board supports connection of up to 12 NTC thermistors along
67 with other capabilities.
69 Installing the electronics in the fin can bay was .. interesting. More later.
73 Parts gathered during October 2010. Built mostly during April and May 2011.
75 The nose cone was custom fabricated by Jeff Lane at
76 [Shockwave Rocketry](http://shockwaverocketry.com), with thermistors embedded.
78 The fins are 3/16 inch birch ply, tapered on the leading and trailing edges,
79 then covered with one layer of 5.7 oz 2x2 twill carbon fiber and a layer of
80 6 oz glass as a sanding veil, all vacuum bagged with West Systems laminating
81 epoxy using a kitchen food saver appliance.
83 The airframe tubing is Giant Leap Rocketry 98mm Magnaframe-based Dynawind,
84 except for a short section behind the nose cone that uses the older phenolic
85 based Dynawind because of the slightly larger inside diameter being a better
86 fit for the glass nose cone shoulder.
88 The tailcone is a no-longer-available Giant Leap 98-75mm Slimline tailcone.
90 All rings and bulkheads were cut using a CNC milling machine from 3/8 inch
91 birch plywood. The fin forward and leading edge rings are made from 3/4 inch
92 thick assemblies made by laminating two such rings with wood glue, to provide
93 sufficient depth for milled fin slots.
95 Assembly techniques were "nothing special" except for the electronics... but
96 I kept a [log](/rockets/airframes/2YikStik/buildlog) that may be of interest.
98 [Photos](http://gallery.gag.com/rockets/2yikstik/)
104 The original objective of flying 2YikStik at NCR's Mile High Mayhem 2011
105 was not met due to weather conditions unfavorable for a high altitude launch.
107 We flew 2YikStik at [LDRS 30](http://ldrs30.org/) on Friday morning. The
108 first couple seconds were glorious! Unfortunately, we hit a wind shear layer
109 just as we were approaching mach, and the side pressure on the nose cone
110 apparently snapped the coupler behind the nose bay, causing the remainder of
111 the propellant to be expended sky-writing instead of going up. Way
114 The airframe didn't get going fast enough before the incident to log any
115 interesting skin temperature data, but the sensor in contact with the motor
116 casing showed the anticipated rise as the motor burned, so we believe the
117 TeleScience boards were working fine.
119 [YikStik3](../YikStik3/) will be our next attempt.
projects / web / gag.com / blob