The Eggtimer Quark is a simple and inexpensive dual-deployment controller. It is ideal for those just getting into electronic deployments or for those who want something the “just works” out of the box. At $20, it’s far and away the least expensive deployment controller on the market. Like our other products, it’s a kit that you have to solder together, but we’ve done our best to make it as easy as possible to assemble. It’s also one of the smallest units available, at only 44mm x 17.75mm it fits comfortably into a 24mm (BT50) tube, and can even fit in an 18mm (BT20) tube if you leave off the terminal blocks and headers. It weighs about 7 grams. It will work with a wide variety of batteries, from 6V up to 15V… a 2S/7.4V LiPo is ideal.
The Quark has two deployment channels, a Drogue channel that fires a small parachute near apogee, and a Main channel that fires a larger parachute at a pre-set and somewhat lower altitude. Main deployment altitudes can be set to 300′, 500′, 800′, or 1000′. The Drogue channel can be set to fire at nose-over (1 second after apogee), or it can be delayed by an additional second for use as a backup drogue channel. Programming is done with simple jumpers; if you leave them all out, the Drogue fires at nose-over and the Main fires at 500′, which are good settings for probably about 80% of all sport rocketry dual-deployment flights.
After landing, the on-board buzzer “beeps” out the apogee of your flight continuously so you can find out how high your rocket went. The apogee of the previous flight is also beeped out when your first power on the Quark, and a deployment channel continuity test is performed before it will start the flight sequence. A series of very distinct tones alerts you to any problems so you can fix it before you fly.
The Quark is fully “mach safe” so you don’t have to worry about premature parachute deployments ocurring due to mach-transition pressure buildup. We use the same code base as the tried-and-true Eggtimer Flight Computer. Also, it features optoisolated bipolar power transistor outputs, which provide inherent current-limiting to prevent dead-shorts from causing “brownouts”. We’ve intentionally dead-shorted the outputs in testing, with no loss of functionality during flight.
Despite its low cost, it has a few features that you’d only expect to see on more expensive units. You can peform a deployment ground test using your battery and your igniter, to make sure that you’re not going to run into any problems during flight. By adding a simple switch and a little bit of wire, it’s possible to perform these tests at a safe distance away from the rocket, so you can actually do a live-charge test using the actual hardware you’re going to fly.
The Quark has a serial output port that’s designed to be used with the standard Eggtimer Rocketry USB-TTL serial data cable, so you can test the output of the barometer chip to make sure that it’s working properly. It also sends out the real-time altitude once per second during flight. With the Eggtimer Telemetry Module (available soon), you can get real-time altitude and status data during flight, streamed to your Eggfinder LCD receiver.