Let's Make Robots!

Second flight with a hexaphenox rocket motor (Success)

Flies now:)

***Update 2011/8/19***

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.

 

***Update 2011/8/16***

Successful static test firing of another 50g hexaphenox, using epoxy as a binder and isopropyl alcohol as a solvant. See first video. 

 

***Update 2011/8/15***

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...

 

***Update 2011/8/13***

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 propellant

 

Removed filter paper. It is now much easier to completely dry the propellant

 

3.1g are residual moisture from the solvent methanol

 

***Update 2011/8/11***

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.

 

***Update 2011/7/31***

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.


TBC

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Thanks, testing the second rocket now:D

MarkusB; What ever you do: Please never stop posting your rockets here. It is so cool!!! So awsome :D

I promise, Frits. And may you not experience the same with your hexacopter :P

Saw your video and remembered my experiements a couple of years back.

We used hair spray aerosol cans, sugar and saltpeter (KNO3) to build rockets or rocket powered boats.

Our problem was to get the diameter of the hole (nozzle) right. Too big and there was not enough thrust and too small the rocket exploded since the melted (caramelized) sugar stuffed the nozzle and the pressure of the still burning motors caused in an explosion.

 

Hi lumi,

Have you casted the R-Candy or just used a powdered mixture?

No, we did not cast it. We just mixed the sugar and the saltpeter together and filled it into the spray can. Then we ignited it with a "wunderkerze" or a bengal fire stick going through the "nozzle" hole in the bottom.

 

Hello just a question .

I have been watching you experimenting with rocket fuels and rocket motors and I wanted to make experiments my self too .

So can you make a tutorial on how to make a simple rocket ?

Hi flokos,

If you want to make a rocket by yourself, the best way is to start with sugar/KNO3. Just google "sugar propellant". There are many tutorials out there:)

If you have never flown a rocket before I recommand to start with a kit, just get familiar with all these things and the theory behind. It is not for nothing called "rocket science":)