Mentos/Coke RocketCar

[Dr Mordrid]

http://www.youtube.com/watch?v=i-hXcRtbj1Y

[Jammrock]

That was funny. Not a clean break from the wall but still pretty good considering the propellant.

[MultimediaMan]

Problem #1 A significant portion of the Mentos get ejected from the bottles during launch. The reactants need to stay in closer contact. Simply putting the mentos into a central "dip tube" chamber, and manufacturing a T fitting with a simple atomizing filter to lead the product of the reactants from the bottle would be more than sufficient to double efficiency: it would also allow the bottles to be oriented upside down.

Problem #2: There is no pressure metering system to allow the reactants to attain a significant (but safe...) pressure before release: a small metal accumulator (Beer keg) and a pressure relief valve would allow the supply side to build a decent head of pressure before releasing it through a common metering nozzle (like a 3" fire hose nozzle).

Problem #3: the vehicle is way too heavy. It could have been built to take less than 50% of the volume and perhaps reduce overall by over 25%.

What says the MURC congnoscenti?

[Dr Mordrid]

I say let's make it using aluminum tubing and power it using a paraffin or acrylic fueled hybrid rocket, something my sons and I have experience building