Meet the Eggtimer Quasar
The Eggtimer Quasar is a barometric altimeter-based flight computer with an integrated GPS and
telemetry transmitter. Its job is to properly deploy your parachutes and bring your high-powered
rocket safely to the ground, and to record flight information for later analysis. When used with
an Eggfinder LCD receiver, it will track your rocket using GPS technology, and send your
rocket’s location to your receiver on the ground. It will also give you its real-time altitude, and
tell you when key events such as deployment channel firing has occurred. If you install the
optional LCD-GPS Module in your LCD receiver, it will point you in the direction of your
rocket and tell you how far to go… long recoveries are easy.
It has three high-current output channels: a drogue channel, which is typically fired near the
apogee of the flight, a main channel which fires at a somewhat lower altitude that you can
choose, and an AUX channel that can be set to act as a secondary drogue or main, or it can be
used as an airstart channel to fire on the way up based on a timer. The idea is that the drogue
parachute is much smaller, so your rocket comes down at a controlled but relatively fast rate,
typically between 50-100 ft/sec. This relatively high rate of descent helps minimize the rocket’s
drift due to wind, and for you impatient types it also helps it come down faster too. The main
parachute is typically opened somewhere between 500’-1000’, slowing the rocket down so that it
lands gently but preventing it from drifting excessively. The AUX channel can be used for
igniting a second stage motor in airstart mode, but it can also be used for things such as air
brakes or as a second main chute for three-way deployments.
It’s nice to get your rocket down in one piece, but it’s also nice to know how the flight went.
The Quasar can record your last 15 flights, and you can easily view and/or download both
summary statistical information and detailed time vs. event information. Data can easily be
downloaded into the standard CSV format for analysis using Excel or other programs.
What makes the Quasar different from other flight computers is that it has a WiFi/browser
interface. Instead of using switches, jumpers, or a data cable to your laptop to program it, you
simply connect to it with your phone, tablet, or computer using WiFi and a browser like Safari,
Firefox, Internet Explorer, or Chrome. You remotely arm it at the pad using your handheld
device too, so for many applications you do not need a mechanical switch… it won’t turn on
until you tell it to. Optionally, you can override remote arming, so it will arm like “other”
altimeters when you power it on. Flight data is downloaded to your handheld device using
WiFi, and with the installation of an appropriate spreadsheet or other data analysis program you
can actually get a flight graph within seconds of recovering your rocket.
Since one of the tenants of successful electronic deployment is ground testing, the Quasar
incorporates a ground-test feature so that you can check YOUR battery with YOUR igniters to
make sure that they are compatible and will work in flight. This is done remotely over WiFi, so
you can even test with “live” pyro charges, standing up to 100’ away from your rocket.
The deployment channels are capable of triggering just about any ematch that you’re likely to
encounter. You can set the output on-time from 1-9 seconds, so it’s ideal for use with a hot-wire
non-pyro deployment. It uses special current-limiting drivers to ensure that a deployment glitch
will not cause your Quasar to “brownout” due to low voltage. You can also use standard PWM
hobby servos with the Quasar, for non-pyro parachute deployments. This makes it ideal for use
To Next Page
Loading...