My Gun Won't Spark

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jjjd
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Wed Nov 29, 2006 12:51 pm

I just Built a swall potato gun out of abs piping and just ude some old skrews in my baesment as conductos but inside the gun it want spark, all the wires are hooked up fine and the sparker still works, could the abs be condicting it?
Tshylea
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Wed Nov 29, 2006 1:13 pm

Well through the terrible spelling I'm assuming you said that you don't have a spark passing between the screws. Make sure they aren't touching or too far apart. Depending on what you are using to make a spark, they should be between around 1/4 inch apart and 1/32 inch apart. Also, make sure the wires aren't touching anywhere else, such as where they attach to the bbq sparker or ignition coil or whatever you used.

EDIT: Also, make sure the screws are clean. If they are dirty that could affect your spark too. Use sand paper to make them nice and shiny.
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jjjd
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Wed Nov 29, 2006 2:56 pm

iv tried all that can it be going through the abs?
Tshylea
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Wed Nov 29, 2006 3:10 pm

I'm not sure where it would be going. Electricity travels in a loop. It comes out the positive side of the source, and goes back in the negative side. It isn't like you can just disperse 100,000 volts into the gun. There is a small possibility that the gun is grounded via the stand that is holding it, but if that is the case you just have to either hold it with your hands when you fire it, or put the stand on a piece of wood or rubber. ABS is a pretty poor conductor, so I'm fairly sure the current wouldn't flow through the ABS between the 2 screw holes, but I suppose it is possible. Try putting the tips of the screws closer together if you think this is happening. Experiment with the gap, because as long as the wires aren't touching anywhere else, and as long as your source is working, you should get a spark.
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jon2680
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Thu Nov 30, 2006 11:53 am

jjjd wrote:iv tried all that can it be going through the abs?
abs doesnt conduct electricity, its plastic.
what kind of screws are you using certin low grade metals dont conduct elec very well.
Try some different screws
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jjjd
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Sat Dec 02, 2006 9:38 pm

k i got it working thanks guys
thedub88
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Sun Dec 10, 2006 3:18 pm

jon2680 wrote:
jjjd wrote:iv tried all that can it be going through the abs?
abs doesnt conduct electricity, its plastic.
what kind of screws are you using certin low grade metals dont conduct elec very well.
Try some different screws
Not true. static does build up on the plastic and your spark can arc to the gun itself.

the most common problem is the spark arcs to the ignitor itself. Use a good quality heat shrink and make sure everything is insulated
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paaiyan
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Wed Dec 27, 2006 10:54 pm

Tshylea wrote:I'm not sure where it would be going. Electricity travels in a loop. It comes out the positive side of the source, and goes back in the negative side.
Just a note, electricity actually travels from the negative to the positive.
ABS shouldn't have any sort of conductive properties that would interfere with the flow of electricity. Like they said, check the screws. Maybe change the screws, not all metals have good conductive ability just because they are metal. try the same size screw made of a different metal.
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Insomniac
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Wed Dec 27, 2006 11:08 pm

@thedub88
Yes static builds up on plastic, but that is the plastic getting either a positive or negative charge. That is different to conducting electricity. A balloon can get a static charge, but doesn't conduct. Copper conducts, but because of this, it will rarely get a static charge.
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