First experiment using white wood glue (polyvinyl acetate) as a binder for the propellant hexaphenox. The advantage is that polyvinyl acetate emulsify very well with a 50:50 ratio of water/methanol and hexaphenox is completely solveable in water/methanol which gives the propellant a high density and therefore a good performance. See last video.
Successful static test firing of another 50g hexaphenox, using epoxy as a binder and isopropyl alcohol as a solvant. See first video.
First experiment by using epoxy as a fuel and KClO3 as an oxidizer. Any shape, any solid fuel or oxidizer or even explosive is possible. See second video how it works...
Another 50g motor casted.
This time I wrapped around filter paper at the inner surface of the PVC tube. This makes it easy to remove the casted propellant from the tube after it is hardened
Removed filter paper. It is now much easier to completely dry the propellant
3.1g are residual moisture from the solvent methanol
Another test firing with 50g hexaphenxo has been done (see third video). Binder: Rosin, solved in methanol, casted into a ID 30mm PVC pipe with 10mm dia core, 48h hardened at 30 ºC.
Second flight was successful and the rocket reached an altitude of 136m. See fourth video!
Since a few month I am exploring the possibility to use hexamine as a rocket fuel. The oxidizer I am using currently is KClO3. I call the mixture Hexaphenox. Hexa stands for hexamine, phen for the catalyst and ox for the oxidizer. After many static test firings I built a small model rocket for the maiden flight. The weight of the rocket was 30g, the weight of engine, containing 10g of hexaphenox, 23.5g. The grain had a continuous core with a dia. of 4mm, the nozzle throat dia. was 4.8mm. Unfortunately the motor had a CATO shortly after lift off. For those who don't know what a CATO is, it stands roughly for a catastrophic motor failure.
I was told, rocketeers call this kind of CATO "crowd pleaser". The motor was chuffing, something that happens when the propellant is ignited near the nozzle instead of at the head of the core. The second video shows a static test firing with ignition on the head of the core - no CATO.
Fortunately I still have some of these Chinese 30 RMB model rockets so I can re-try it tomorrow.
Launch pad and rocket for the second attempt
Single frame image converted from the launch pad camera.