4. Connect to the flight computer, tap “Thrust Vectoring”, then “Advanced”
5. Get your head close to the top of the rocket on one axis(in line with a TVC servo, X or Y)
and look down the length of the rocket to the bottom. The motor tube sticking out might
not be perfectly centered.
a. If there’s a bit of play or slack in the mount’s position, that’s okay in small
amounts. Gently push the mount back and forth to estimate where the center of
the slack is, and use that position to judge the alignment of the mount.
6. Use the + and - buttons on your iPhone or Android device to move both the X and Y axis
to their center positions
7. Once everything is centered, the long motor tube should look like a straight extension
from the airframe.
8. Remove the long motor tube, and you’re all set!
10. Parachutes and pyros
Your rocket still needs parachutes, and a way to get them out of the vehicle in time. You can’t
use a motor ejection change, so you’ll need to wire up those pyro channels to black powder
charges. If you’re unfamiliar with how to build a piston based parachute deployment system, or
the required ejection charges,
check out this part of the “Build Signal Alpha” series.
11. Tuning
Before you launch your newly built rocket, you’ll need to tune it for flight. This involves finding
the inertia of the vehicle and running it through a flight sim to generate safe P, I, and D gains.
The methods used here are the same used by NASA to tune many of their experimental aircraft!
The Signal app has the steps and tips for tuning your rocket. You can click the “?” button in the
tuning section. That said, it’s easier to follow along on a computer, and the steps are all here:
12. Flight tips
With your tuned PID values loaded into Signal R2, you’re ready to fly! Here are a few tips to
help the first flight work well.
● Because thrust vectoring keeps the rocket stable, you do not need to launch from a rail
or rod. If you want, you can build your own launch pad without them. That said,
launching from a short rail is usually best to ensure the vehicle stays upright before
launch.
● Do not use a launch rod, use a launch rail.
○ Because the rocket can roll around the launch rod, any type of correction
maneuver in the TVC will induce roll on the vehicle while it is still connected to
the rod. Launch rods are also a bit more flexible, and may whip the rocket around
as it leaves the rail, which can be bad for stability
Copyright © 2019 Barnard Propulsion Systems, LLC
Version 1.8, Jan 1, 2019
