SpudFiles

This is basically version 1.5 of my mini. In the end I would like to increase the length of the barrel and mount it onto a wooden frame in the shape of an an old hunting rifle, it will fire plastic BBs with a bit of cotton wool as wadding, and I will fashion a scope for it (just for looks!). As you can see its all ready to be mounted since I measured the wire length with my design for the frame before cutting.

However, it just seems extremely under-powered right now, even with the very short barrel ( modified pen tube). I decided to post it before I started work on the frame, so that if it is unsalvagable I won't be wasting any more time on it. It uses adidas deodorant as fuel, cotton wrapped BBs as ammo and a black peizo ignitor (with the copper tube) as a source of ignition. Also it does not have a very high success rate when it comes to firing, but thats probably just me putting in too much fuel.

Any ideas?

maybe the barrel is too short? I have a coke bottle gun and the barrel is only as long as the bottle and it sucks

Edit:ya, didnt think of that(different fuel as mentioned below) try using the butane from the lighter you got the piezo out of (although it might take alot of butane)

try a drifferent fule

I did try the butane however it is even harder to get the right amount and when I did the flame wasnt even visible but I will definately try again now that you mention it.

Also is it possible that my spark is not in a good position for ignition?

I believe your barrel is definitely too short as has already been said. I would
make it one and a half times your chamber or longer. This is not based on
any formula just what I have found to work ---in my humble opinion. I have a
1/2" barrel with 1 1/2" chamber mini with those figures; it uses -uh- body
fragrance spray (I don't want to hear any snickers please) and spuds. I can
get 100' to 150' with this combo. It's great for varmint chasing and just plain fun. I don't see any fault with the placement of your spark but I do agree you
don't need much fuel; err on the side of too little rather than too much. Take
this from a 63 year old who keeps spudding away. BTW-I love this forum and the many fresh ideas I encounter-one is never too old to learn new things!