Eggtimer Builds

Eggtimer Rocketry ( has been around for a long time and offers a wide range of flight computers and tracking components specifically designed for use in rocketry. Cris Erving is the owner and mastermind behind Eggtimer and continues to innovate new products all the time. His offerings provide an incredible amount of power at very low costs (compared to other rocketry electronics manufacturers). For only $15 you can get an apogee deployment device and, remarkably, for $20, you can get a fully functional dual-deploy flight computer (the Quark) that not only has a full menu of deployment settings, but is also small enough to fit in a 24mm tube! On the high end, you can get the Proton with both an accelerometer and a barometric sensor and a whopping 6 highly programmable event channels all for $70. To compare, I am not aware of any other flight computer on the market that can match the Proton for under $300. On the tracking side of the fence, you can get started with an LCD receiver kit and a GPS mini-tracker for $130. That is stupendously low compared to anything else on the market. And, Cris offers a dizzying array of modules to allow you add functionality to both the flight computers and tracking systems. 

Okay, now you are saying – “This sounds too good to be true.. what’s the catch?” There is one significant catch – Cris only sells you the kit. You need to solder everything yourself. I can hear a collective “Yikes!” let out! I understand completely. You look at some of those devices on the Eggtimer website and are thinking “What? You’re crazy. I don’t have the soldering skills for that!”

This page is designed to help you out with the build side of the equation. Cris provides amazingly good instructions with his kits. Far better than the normal 2-3 page “guide”. He shows you, in detail, how to build each of his kits. If you follow his instructions to the letter, you will be successful. However, words and pictures in a document are only so good. Here, I will provide you with videos of all the Eggtimer products and show you exactly how to follow the instructions in the real world. I am 100% confident that you will only need to complete one or two of these builds and then you won’t ever need the help again. But, starting out can be really daunting.

So, buckle up, put on some eye pro, fire up the soldering iron, turn on the vent fan and let’s get building!

Setup and tips

This section will contain tips on soldering and setup.

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Eggtimer Proton (New Version - Rev c14, Fall 2023)

The Eggtimer Proton is one of the most advanced flight computers that you can buy.   It combines SIX deployment channels with a 120G accelerometer, perfect for those really ambitious projects.  It’s also WiFi-enabled, so you don’t need to mess with any cables or special software to configure, download, or perform depployment tests.   In addition to the “standard” Drogue, Main, and Airstart modes  you can also configure the channels to trigger on almost any condition that you can think of, and there are no dedicated channels… any channel can perform any function.   It has lots of safety features, including our exclusive dual-switched outputs that essentially leave the outputs “dead” until you’re in flight.  There is also servo support on the way down… do you want to go Falcon 9 and have landing gear deploy using servos after the Main chute opens?   You can do it with the Proton!

Eggtimer Quasar

The Eggtimer Quasar combines a 3-output WiFi-enabled flight computer with an Eggfinder-compatible GPS tracker.  On the altimeter side, it has 3 outputs: Drogue, Main, and a configurable AUX output that can act as an airstart timer or a backup Drogue or Main. Like the Eggtimer Quantum and Proton, it’s WiFi enabled… all functions are remotely configured via a WiFi/browser interface (no Internet or apps needed): changing settings, arming/disarming, downloading flight data, and performing deployment tests.  

On the telemetry side, it sends out GPS and altimeter telemetry once per second. It uses the same tried-and-true Eggfinder LCD receiver, and displays your real-time altitude and deployment channel status, and apogee after landing.   It’s available in the license-free 900 MHz band, the EU/UK 869 MHz band, and the 70cm Ham band.

Eggtimer Quantum

The Eggtimer Quantum is the  first WiFi-enabled flight computer.  Using just about any WiFi/browser enabled device, you can program,arm/disarm, and download data without any cables, apps, or Internet connections.  It’s the easiest full-function alltimeter that you’ll ever use!  Features include two high-current deployment channels, airstart capability with velocity/altitude/breakwire tests, remote deployment testing, and lots more.

Eggtimer Classic (Deprecated, July 2023)

The Eggtimer Classic Flight Computer is a full-function barometric two-channel flight computer that can be used to deploy parachutes, airstart second-stage engines, and log flight profile data.    It supports standard main-drogue  multiple chute deployment, or you can use your motor’s ejection charge to deploy the drogue chute and configure the drogue channel in airstart mode to support a two-stage multiple deployment rocket.  It can be used to modulate  standard hobby servos too, so if you’re a water rocket enthusiast this is the least expensive  solution on the market that can be used for non-pyro multiple deployment.  With all through-hole assembly, it’s also the easiest altimeter to assemble that we offer.


Eggtimer Quark

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.   It’s also one of the smallest units available, at only 1.8″ x .75″ it fits comfortably into a 24mm (BT50) tube.   Just because it’s inexpensive doesn’t mean you give up features… there are two drogue settings, four main altitude settings, you can perform deployment channel tests (can YOUR basic altimeter do that?), and it beeps out the apogee after landing

Eggtimer Apogee Deployment Controller with Easy Mount

The Eggtimer Apogee is the easiest and least expensive deployment altimeter on the market. In a tiny 1.75” x .9” package that fits into a 24mm motor mount, the Apogee deploys your parachute at apogee and beeps out your altitude, with no programming of any kind. It has a built-in NAR/TRA-approved screw switch, and an on-board JST-PH battery connector for small 1S LiPo batteries. It’s the ideal companion for a Jolly Logic Chute Release™ because it does the things that the JLCR cannot… get the parachute out and tell you how high you went.

Not only is it easy to use, but it’s also easy to build.   With almost all through-hole parts, it’s designed to be easily built by just about anyone.

Also available is a special 3D-printed Easy Mount for the Eggtimer Apogee (designed by Chris Bender of Lab Rat Rocketry), it makes it a snap to install an Apogee into most 38mm or larger nose cones. It can be easily interchanged from one rocket to another, and includes a built-in charge well and terminal screws. It’s designed to use a tiny 110 mAH 1S LiPo battery, which Eggtimer Rocketry will also be sourcing.

Eggtimer WiFi Switch

The Eggtimer WiFi Switch is the answer to the question, “How to you turn on something in an AV bay when it’s 8 feet off the ground?”   Using ANY WiFi/browser enabled device, you can turn your electronics on and off, over 100′ away.  Have a two-stager and don’t want to stick your face next to a K sparky motor to turn on the altimeter while standing on a ladder?   No problem… with the WiFi switch, you can stand back and turn it on remotely.   Not only that but it has two continuity checking circtuits, that can connect to ANY altimeter… not just Eggtimer products.   You can remotely check continuity, and battery voltage too.

Eggtimer Telemetry Module

The Eggtimer Telemetry Module is an add-on for the Eggtimer Quark, Quantum, and Proton altimeters.   It transmits flight data to an Eggfinder LCD receiver on the ground, giving you real-time visibility into what your rocket is doing.   Typical real-time data can include altitude, velocity, acceleration, elapsed flight time, flight phase, deployment channel status, voltage, and temperature.   You also get “historical” data such as apogee, maximum velocity, and maximum acceleration.   (Actual data is dependent on device)   This is a great companion to an Eggfinder GPS tracker… the GPS tells you where you rocket is located, and the telemetry tells you what it’s doing.   Have you ever lost sight of a rocket and wondered how high it was, if the deployment charges fired, or how fast it was descending?   Well, now you’ll know!

Eggtimer Voice Module

The Eggtimer Voice Module is an add-on for the Eggfinder LCD receiver, when used with the Eggtimer Telemetry Module it will speak out your real-time altitude, apogee, and deployment events (depending on which Eggtimer altimeter it’s used with).   This gives you instant feedback as to the performance of your rocket, and also confirms that your ejection charges have fired.   It can be used with standard 3.5mm earbuds, or you can attach a 3.5mm AUX cable to it and use an amplified speaker, your car stereo, or your club’s PA system to let everybody know how awesome your flight is.

Eggfinder TX Transmitter

The Eggfinder TX transmitter is our “basic” transmitter, designed to be mounted in the nose cone of most hobby rockets.  It measures about .9″ x 3″, and the antenna adds about another 3″.   It can easily fit in the nose cone of a 38mm or 54mm rocket, and can fit into a 29mm coupler if you have enough length.   The Eggfinder TX will also take an OpenLog datalogger module, so you can save your NMEA-formatted data to a micro-SD card so you can import the data into a program like Google Earth and get a really cool track of your rocket’s path.   You can program it to any one of 72 frequency/ID combinations using the  included pairing cable with an Eggfinder LCD receiver (non-US frequncies/ID’s may vary).

Eggfinder Mini Transmitter

The Eggfinder Mini is the smallest GPS transmitter available, a mere .7″ side x 3.25″ long INCLUDING the antenna.  It will even fit into an 18mm body tube, and it uses a special stubby antenna to make it even smaller.   It’s so small that you can easily wrap it up in a Nomex “burrito” and attach it to your shock cord… no special sled necessary.   There are some 3D-printed mounts available specifically to mount it in a 29mm or 38mm nose cone.   It is functionally identical to the Eggfinder TX transmitter, except that there’s no place to add an OpenLog datalogger (just no room…)

Eggfinder RX "Dongle" Receiver

Our “basic” receiver, the Eggfinder RX plugs into your laptop (with the USB cable option) and can be used with software such as MapSphere to track your rocket in real time.    With the Bluetooth option, you can send the GPS data to an Android device and get the coordinates and the track of your rocket using programs such as GPS Rocket Locator or Rocket Tracker.   It’s ideal for setting up a “ground station” receiver with a laptop/tablet to get a real-time track of your rocket.

Eggfinder LCD Handheld Receiver & Black Aero Case v3 Pro

The Eggfinder LCD receiver has a display that shows you the GPS coordinates, GPS altitude, and some fix quality informtion, and can be easily taken with you to retrieve your rocket so you have the most current GPS location as you approach it.   In addition, we make a GPS module add-on for the LCD receiver, which gives you a single-device tracking solution.   You get the the distance to your rocket, its compass direction in relation to you, your track (the compass direction that you’re moving), and the best part… an arrow and bearing to your rocket.   You follow the arrow and it literally takes you to your rocket.   It’s about the easiest tracking solution there is.  You can also add a Bluetooth module to it so you can use it for real-time tracking with an Android device, as well as having the GPS coordinates displayed. 

Eggfinder LCD-GPS Module

The Eggfinder LCD-GPS Module is an add-on for the Eggfinder LCD receiver, it gives you a single-device tracking solution… no phone/tablet/laptop required.   In addtion to the standard GPS coordinate and GPS ASL altitude display, you also get the distance to your rocket, its compass heading in relation to you, your track (the compass heading that you’re moving at), and (the best part…) an arrow and bearing to your rocket.   You just follow the arrow and it will literally take you right to your rocket.   It’s the easiest tracking solution around!

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