Hi guys, I have holidays coming up and if I have any spare time (Which I doubt), Id like to build an orange gun. For those of you who dont know, Im talking about some pvc pipe with an orange/potato shoved up it. Spray some hair spray down there and spark away. Anyway, instead of just hacking one together, I was thinking about actually designing one properly. ie Combustion chamber size, barrel length etc. I reckon it would be interesting to measure how far one could shoot. Anyway, has anyone made these before and any tips?