last updated: 21st october 2023 - Day 226 to Day 230 - Various Experiments

Safety First


Site Index



Rocket Gallery


Where To Buy

10 Challenges




Contact Us


Construction - Basic


Ring Fins

Flat Fins



Construction - Advanced

Robinson Coupling

Splicing Bottles #1

Splicing Bottles AS#5

Reinforcing Bottles

Side Deploy #1

Side Deploy #2

Mk3 Staging Mechanism

Multi-stage Parachutes


Construction - Launchers

Gardena Launcher

Clark Cable-tie

Medium Launcher

Cluster Launcher

Launch Abort Valve

Quick Launcher

How It Works

Drop Away Boosters

Katz Stager Mk2.

Katz Stager Mk3.


Dark Shadow Deployment


Recovery Guide


How Much Water?

Flying Higher

Flying Straight

Building a Launcher

Using Scuba Tanks


Video Taping Tips

MD-80 clone

Making Panoramas


Burst Testing





Servo Timer II




V1.3, V1.3.1, V1.3.2


Deploy Timer 1.1

Project Builds

The Shadow

Shadow II


Polaron G2

Dark Shadow

L1ght Shadow

Flight Log Updates

#230 - Tajfun 2 L2

#229 - Mac Uni AON

#228 - Tajfun 2 Elec.

#227 - Zip Line

#226 - DIY Barometer

#225 - Air Pressure Exp.

#224 - Tajfun 2

#221 - Horizon Deploy

#215 - Deployable Boom

#205 - Tall Tripod

#204 - Horizon Deploy

#203 - Thunda 2

#202 - Horizon Launcher

#201 - Flour Rockets

#197 - Dark Shadow II

#196 - Coming Soon

#195 - 3D Printed Rocket

#194 - TP Roll Drop

#193 - Coming Soon

#192 - Stager Tests

#191 - Horizon

#190 - Polaron G3

#189 - Casual Flights

#188 - Skittles Part #2

#187 - Skittles Part #1

#186 - Level 1 HPR

#185 - Liquids in Zero-G

#184 - More Axion G6

#183 - Axion G6

#182 - Casual Flights

#181 - Acoustic Apogee 2

#180 - Light Shadow

#179 - Stratologger

#178 - Acoustic Apogee 1

#177 - Reefing Chutes

#176 - 10 Years

#175 - NSWRA Events

#174 - Mullaley Launch

#173 - Oobleck Rocket

#172 - Coming Soon

#171 - Measuring Altitude

#170 - How Much Water?

#169 - Windy

#168 - Casual Flights 2

#167 - Casual Flights

#166 - Dark Shadow II

#165 - Liquid Density 2

#164 - Liquid Density 1

#163 - Channel 7 News

#162 - Axion and Polaron

#161 - Fog and Boom

#1 to #160 (Updates)



Each flight log entry usually represents a launch or test day, and describes the events that took place.
Click on an image to view a larger image, and click the browser's BACK button to return back to the page.

Day 48 -  J4 IIIb Crash and Foam Flights with Altimeter
Setting up J4IIIb for a water only, altimeter flight to compare to foam.
The kids did a great job of helping with the experiments.
We were only flying the rocket at 110psi to make sure it stayed within the park. Here it reached 89m (292') Mostly because it did not go directly vertically.
Second launch with camera and foam. Again the rocket went a fair way from the pad and not straight up.
Although the parachute deployed just past apogee at 99m (324'), it did not blossom until 25m (84') above the ground.
Third launch of J4IIIb left a great foam trail.
The parachute failed to open in flight and the onboard camera failed to record the launch.
Flight computer in the nosecone was destroyed by the battery behind it. The servo was also destroyed, the camera separated and went flying a few meters from impact site and the altimeter is hanging out.
The altimeter recorded this data. It lost power on impact and so did not properly store the remainder of the flight.
max altitude reached: 107m (350')
Graviton launched without a gravity experiment payload just for fun.
Last landing for the day landed on the car park about 10 m from the road.
Date: 28th October 2007,      7:30am - 9:00am
Denzil Joyce Oval
 18 degrees C, Westerly at 12km/h, cloudless sky
Team Members at Events: GK, PK, Paul K, John K

Well finally the weather cleared up and we were able to get a few launches in this weekend. We were going to be testing water vs foam flights using the altimeters, but one thing lead to another and we just ended up launching them for fun. Here are the details of the flight day.


  • As we arrived at the launch site we discovered that there was a plague of flies. With the warm weather we have been having lately they must have all emerged at the same time. After 5 minutes of spending more time swatting them away than setting up the launcher, dad jumped in the car and went home to pick up insect repellent. It's good to live within 2 minutes of the launch site. As I sprayed myself head to toe with repellent I began to wonder if I should take fly-induced drag into account in the rocket calculations.
  • Although the first flight pitched over a bit after take off it came down well under parachute. Max altitude reached was 89m. We were only flying the rockets on relatively low pressure to keep them within the park. We also set the parachute deploy delay to half a second later than normal to minimise drift on the way down.

    The only damage was when the nosecone hit the ground and the servo motor popped off its mount. We tried to fix it, but one of the screws stripped the thread where it was attached and so we decided to simply swap the entire payload section we brought as a backup. This payload also had an altimeter already mounted and the weight of the entire section was identical to the one we replaced.

    The nosecone also head a removable camera mounted in it, so it weighed a little more and had a bit more drag but we were going to fly it anyway. We wanted to at least get some footage with foam, and then remove the camera for the next flight and fly a foam comparison mission with an identical setup to the first water-only flight.
  • After the rocket landed everything looked fine, but we discovered that the camera did not record anything. I was pretty sure it was recording when we launched, so I wasn't too sure what had happened.
  • We launched it again with the camera and altimeter. This time the rocket took off at quite a bit of an angle and headed straight for the river. The parachute failed to open and the rocket heavily crashed through some trees and on the other side of the river. It took us a few minutes to find it.

    The flight computer was totally obliterated mostly by the battery that was located just underneath it. The altimeter was hanging out the side and the camera had completely detached and was lying a few meters away. We checked the camera and although it turned on, we saw that nothing was recorded again. Arrrgh! I tried doing a record test and half way through a recording the camera just shut itself off. I am not sure yet if the camera is damaged or perhaps the battery might be low. Although we did replace the batteries recently. We will have to do a few more tests.

    The altimeter survived, and despite having its power cut on impact still managed to record almost the entire flight with the exception of the last few samples. A couple of the connector pins were bent on it, but that's all. The servo motor was also destroyed as the gears are locked together and you can no longer turn the arm. One of the fins was also destroyed, and we only found the base part of it.
  • We do not know why the parachute failed to deploy. It is just one of those things I guess.
  • We then launched the Graviton rocket a couple of times since J4IIIb could now easily fit in the car's glove compartment. We didn't have a gravity experiment in the payload but instead just flew it with foam for the kids. Both flights went well without incident. We taped the other video camera to the side of the rocket and ended up with a semi decent video although the rocket had a bit of a spin to it.

(If the video does not play, try the latest Flash player from Macromedia)

What's next?

We are now going to seriously look at a new nosecone design. We have been designing the payload section as lightweight as possible and with the view that all landings would be gentle. Figuring if we had a hard landing there wasn't much we could do anyway, and we would just rebuild the broken ones. We are now going to change things quite a bit and allow the nosecone to come down hard without destroying anything valuable. With padding and crumple zones it should be able to protect the rest of the payload better. It should be relatively simple to then replace just the outer skin.

The flight computer is also going to get an upgrade and will be integrated with the altimeter. Currently I have my hands full before a launch in setting up the flight computer to the right time, arming, zeroing the altimeter, starting the recording, turning on and starting the onboard video camera and finally video taping the whole launch from a distance. A lot of this happens just before pressurising and the camera start happens after pressurising so there is always a danger the rocket could go bang on the launch pad, when starting it..

If we can get the camera open and gain access to the switch contacts, I will try to get the flight computer to switch the camera to the right mode and start recording, automatically.

I would like to start the entire process remotely with an infrared remote control, so that no one needs to be near the rocket after it is pressurised. Everything on board the rocket will be automated. Although this might take a bit of time to set up, it will be essential once we start using higher pressures in our rockets.

Once the nosecone is redesigned we will get back to comparing the water and foam flights.

Recording Flights

We are now using a standardised form for recording all flights. We used to just write down the details as they happened, but sometimes forgot to include everything. The form also allows us to record the info quickly and consistently. Although it might seem like overkill for the hobby, we find it very useful to go back and refer to previous flights when we are trying to analyze performance or when something goes wrong.

We also capture weather data from the internet for the closest weather station to get the environmental data over the course of the launch day.

Flight Details

Launch Details
Rocket   J4 IIIb
Pressure   110 psi
Nozzle   9 mm
Water   1500 mL
Flight Computer   V1.3.2 - Setting: "9"
Payload   Altimeter
Altitude / Time   89 m / 20.4 s
Notes   Parachute deployed after apogee as expected. Good descent and landing. Servo motor popped off mount, otherwise no damage.
Rocket   J4 IIIb
Pressure   110 psi
Nozzle   9 mm
Water   1.25 L + foam, using Jet Foaming.
Flight Computer   V1.3.2 - Setting "9"
Payload   Altimeter, camera
Altitude / Time   324 feet ( 99 m ) / 14.8 seconds
Notes   Parachute deployed past apogee as expected but tangled, and opened 25m above the ground. Camera failed to record.
Rocket   J4 IIIb
Pressure   110 psi
Nozzle   9 mm
Water   1.25L + foam, using Jet Foaming.
Flight Computer   V1.3.2 - Setting "9"
Payload   Altimeter, camera
Altitude / Time   350 feet ( 107 m ) / 10.6 seconds
Notes   Tipped over quite a bit after launch, failed to open parachute. Heavy crash, nosecone destroyed, altimeter recorded flight, camera failed to record again.
Rocket   Graviton
Pressure   110 psi
Nozzle   9 mm
Water   850mL + foam, using Jet Foaming.
Flight Computer   V1.3.1 - Setting "7"
Payload   Camera
Altitude / Time   Unknown / 14.3 seconds
Notes   Good flight, almost vertical. Parachute opened at apogee. Good landing.
Rocket   Graviton
Pressure   110 psi
Nozzle   9 mm
Water   850mL + foam, using Jet Foaming.
Flight Computer   V1.3.1 - Setting "7"
Payload   None
Altitude / Time   Unknown / 20.9 seconds
Notes   Excellent flight, Good foam trail, parachute opened at apogee. Good landing

<< Previous       Back to top      Next >>

Copyright © 2006-2023 Air Command Water Rockets

Total page hits since 1 Aug 2006: