Latest Update:6th July 2018 - Day 199 - Phoenix 3D d78 Nosecone and UNSW Visit

Day 194 - Toilet Paper Roll Drop

Date: 27th January 2018
Location: Whalan Reserve, Australia
Conditions: Cloudy, wind 5-10km, 32C
Members: PK, John K, and GK

Toilet Paper roll drop experiment

While we work on the horizon rocket, we took a quick break this weekend to do a couple of fun flights. A few months ago we saw one of Tucker Gott's videos where he drops a roll of toilet paper from 2000 feet from his paramotor. This was pretty cool so we thought we'd have a go to see if we can drop a roll from one of our water rockets.

The mechanism for dropping the roll is pretty simple. We screwed a tornado tube to the top of the nosecone, and then we screwed in a PET bottle preform to the top of it. The toilet paper roll then just slides over the top of it to keep it in place on the way up. One of the things Tucker mentioned was to unwind some of the roll so that it would create drag and get the whole thing unwinding. So for this we unrolled a couple of feet but then folded that up and pressed it against the roll. In order to prevent it from coming loose on the way up we added a rubber band and attached it at the bottom of the tornado tube. This was threaded through the roll and over the loose end of the paper. The other end of the rubber band was then hooked onto the same servo motor that the parachute was connected to. This also stops the roll from drag separating on burnout.

After the rubber band is released, to get the roll to come off the nosecone we tied the parachute cord a little bit behind the center of gravity of the rocket so the nose would point down when under parachute, and gravity would do the rest. In order to make it a little more aerodynamic on the way up we also added a simple nosecone that would just slide off with the roll.

Unfortunately we didn't have blue skies on this launch which made it a little harder to see the white paper against the white clouds. So here are the highlights from a couple of flights.

We used our reinforced Axion G6 rocket for this flight as it can lift a heavier payload. We also mounted a camera on top of the rocket looking up so that it would try to film the roll as it released and came off the rocket.

The two flights went well and released the roll just after apogee. The roll unwound fairly quickly and then proceeded to drift down gently. From the on-board video you could see that as the rubber band over the roll was released while there was some airflow over the rocket the roll started spinning while still on the rocket before sliding off. The paper must have caused enough drag to cause it to start unwinding.

On the second flight after the roll was fully unwound, the rocket managed to find its way back to the paper and catch it in its shroud lines. The two then landed together in a low tree. In both cases we were able to recover the toilet paper.

Flight Details

 

Launch Details
1
Rocket   Axion G6
Pressure   200psi
Nozzle   9mm
Water   1500mL + foam
Flight Computer   STII - 4 sec
Payload   Roll of Toilet Paper, HD Cam #16
Altitude / Time   ? / 28.8s
Notes   Good straight flight with parachute deployment just before apogee, roll released just after apogee. Good landing..
2
Rocket   Axion G6
Pressure   200psi
Nozzle   9mm
Water   1500mL + foam
Flight Computer   STII - 4 sec
Payload   Roll of Toilet Paper, HD Cam #16
Altitude / Time   ? / 29.7
Notes   Good straight flight with parachute deployment just before apogee, roll released just after apogee. Shock cord caught the toilet paper roll again on the way down. Good landing in a low tree..