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Bbq Lighter?
Posted: Fri Sep 26, 2008 2:25 am
by Reaper1232
Hi,
I am currently constructing my first potato cannon and am having some difficulty. I purchased a standard BBQ Lighter to act as the igniter in the chamber. My chamber is very large so i thought it would be best to have it set up to spark at 3 different points. I drilled in 3 pairs of screws and i tested the pairs individually, each time they set off a spark inside the chamber.
However once i connected the 3 pairs into a sequence, none of the points ignited. Is this because the BBQ lighter is not strong enough to do a triple spark? How would i go about giving it extra power?
Cheers..
-Reaper
Posted: Fri Sep 26, 2008 2:31 am
by Hubb
The points need to be closer together. Check out spark strips in the wiki.
Posted: Fri Sep 26, 2008 2:07 pm
by jimmy101
Hubb is correct.
The total gap length needs to be less than the maximum length of a single gap.
If one 1/4" gap fires consistently then each of the three gaps will need to be 1/12" gap or less. Add a bit of windage, and figure the individual gaps need to be 1/16" or less.
Posted: Sat Sep 27, 2008 3:28 am
by Reaper1232
Ah k thankyou.. This is a problem though seeing as I would need to unscrew the screws then screw them all back in. Probably weakening the pipe in the mean time by doing it. Oh wells..
Cheers
Posted: Sat Sep 27, 2008 9:18 am
by starman
Unless you're prepared to do some more precision work getting these gaps narrowed, it will not work properly. Maybe you should consider scoping down to 2 or even a single gap. It also may require a chamber rebuild to do correctly and safely.
Posted: Sat Sep 27, 2008 12:15 pm
by Eddbot
just disconnect the other two gaps from the circuit, you can just leave the other screws in, that shouldn't affect performance or safety
Posted: Sat Sep 27, 2008 1:22 pm
by nibbler125
ya youre gaps need to be closer no biggy just add some soder or a hunk of wire to the end of the screws to make them closter together
Posted: Sat Sep 27, 2008 1:47 pm
by explsvcookie257
You could try wrapping tin foil around the ends I did that it also keeps the screws from getting gunked up but I use carb cleaner now in my combustion and dont have that problem. Also I have had the same peice of tinfoil there for like over 50 shots and its doing fine.
Posted: Sat Sep 27, 2008 5:22 pm
by Reaper1232
The tinfoil or wire idea sound good.. Although as this was just my first cannon i got lazy and didnt cut the pipes down. It was just an experiment till I build a more advanced one. So the chamber is about 1 metre long. Might have trouble reaching down to the front screws to wrap foil around them haha
But I shall try that. Thanks heaps.