# YikStik3

## Motivation

This is a "replacement" for Bdale's first L3 certification airframe, 
[YikStik](../YikStik), which was mostly lost... and a follow-on to
[2YikStik](../2YikStik), which had one and only one "way too exciting"
flight at LDRS 30.  We recovered the nose cone, tail cone, rail buttons, 
and all of the electronics from 2YikStik.  Everything else is new for this
build.

Robert is very interested in measuring the temperature of a nose
cone and a fin on a rocket at speeds above Mach.  This led Bdale to design
a [TeleMetrum](http://altusmetrum.org/TeleMetrum) companion board called
[TeleScience](http://altusmetrum.org/TeleScience) capable of hosting up to
12 NTC thermistors for temperature data collection.  
As was the case with 2YikStik](../2YikStik), the plan is to fly two
[TeleMetrum](http://altusmetrum.org/TeleMetrum)+[TeleScience](http://altusmetrum.org/TeleScience) 
setups, one mounted in the nose cone and one mounted 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.

We will again fly a custom 98mm nose cone with the temperature sensors
embedded in the glass layers made for us by Jeff Lane of 
[Shock Wave Rocketry](http://shockwaverocketry.com/).

## Design Details

* 98mm [Performance Rocketry](http://performancerocketry.com) G-10 convolute glass 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 3/16 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 
  fin alignment.

The OpenRocket design file is 
[YikStik3.ork](/rockets/airframes/YikStik3/YikStik3.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 1000 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 late 2011 and early 2012.  Built underway in early
March of 2012.

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.

We're moving from the Giant Leap Rocketry 98mm Magnaframe-based Dynawind to
G-10 glass tubing this time around.  Dynawind is lighter and strong enough,
but we want to use glass couplers this time around for more strength, and 
that leads to fit issues with the Magnaframe-based Dynawind tubing.  So even
though it's slightly heavier, we're going with an all-gladd build this time.
We'll lose a little bit of max velocity, but hopefully it'll all hang together
this time!

The tailcone is a no-longer-available Giant Leap 98-75mm Slimline tailcone
recovered from 2YikStik's wreckage.

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.

Will add a pointer to build photos here once they are available.

## Publicity

## Flights

The intended first flight of YikStik3 will be at NCR's Mile High Mayhem 2012
on an as-yet-unreleased [Cesaroni](http://pro38.com) Pro75 6xl Imax reload 
tentatively designated 9874M2245, which is a 92.7% M with approximately 
4.4 seconds burn time.  It's going to be one heck of a ride!