User`s manual

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OUTSIDE of the AV bay, away from the allthreads. To do that, you will need to install an RP-
SMA connector instead of the wire antenna, and you may need to get a short RP-SMA male-
female cable to bring the connector outside. Simply use the cable to bring the connector outside,
screw your antenna into it (rubber duckies work well for this…), and wrap the cable/antenna
around your shock cord with some duct tape. You need to strain-relieve the cable so that it can’t
get pulled, leave a little slack and zip-tie the end to the shock cord mount.
Alternatively, you can get a long RP-SMA female edge connector, one that’s designed for
bulkhead mounting, and screw it to the AV bay bulkhead. You’ll need to rigidly mount the sled
on that bulkhead, you don’t want it moving, but if the bolts on the allthreads that hold the AV
bay together are removed from the other side then that won’t be a problem. If you go this way,
make sure that the antenna can’t be damaged by the shock cord whipping around; it’s probably
better if you mount the antenna on the drogue side, since there’s invariably a lot more room to
work with, and the deployment of the drogue is usually somewhat softer than the main.
Batteries can be mounted in several ways. Small zip ties work well, so does double-sticky foam
tape for LIGHT batteries (like 200 mah LiPo batteries, for example). If it’s a rechargeable
battery and you don’t expect to remove it, a dab of epoxy works too. Do NOT use double-sticky
Velcro, it WILL come loose in flight and is a magnet for static electricity.
No matter how you mount the batteries, make sure that they can’t work loose during flight. That
would be bad… you could lose your deployment power AND your GPS feed.
Multiple Deployment Hints
1) ALWAYS weigh your completed rocket with all batteries and the motor that you plan on
using, determine the CG, and run it through a program like RocSim or Open Rocket to check the
stability and predicted flight path of your rocket. Google to see if there is a RocSim file for your
rocket, and/or modify it accordingly if you have made changes or have a custom build.
Yes, this IS rocket science…
2) Similarly, use RocSim/Open Rocket to determine the best delay time for the drogue
deployment. Ideally, it should be within +/- one second of predicted apogee, when your rocket is
moving at a relatively slow speed (< 20 ft/sec is ideal). If you are going to use the motor’s
ejection charge to fire the drogue, and the motor has a fixed delay time (i.e. one that you cannot
“drill out” to adjust), it might be a good idea to do this before you buy your motors, so you can
purchase them with the correct delay time. Of course, if you’re using the Eggtimer for drogue
deployment you don’t need to worry about this.
3) Prior to flight, perform a Ground Test procedure with a test load and your ignition battery.
We recommend using miniature Christmas Tree lights, they work very well for testing with just
about any battery that would light up an igniter. You should perform at least one Ground Test
with the pyrotechnic charge that you are going to be using to be absolutely sure that it will fire
with the battery that you choose, and that it’s strong enough to kick out your parachute. This
obviously should be done OUTDOORS in a well-ventilated area. If you have an Eggfinder
LCD receiver, this is easy. There may be local regulations that prohibit pyro testing where you