Hubb's Improved Spark Strip
Posted: Sun Jul 27, 2008 10:02 am
Some of you may remember seeing my spark strip design under my combustion launcher. I'm in the process of redesigning the launcher and one of the things I wanted to improve was the spark strip, making it more user friendly.
The way it's designed is to allow a spark in the rear, the middle, and the front of the combustion chamber. It has three gaps and each gap is fully adjustable (depending on screw length). The gaps can also be closed, allowing for just one or two sparks (for piezo igniters). It also has a built in fan, which is held in place by a zip tie, allowing it to be removed if necessary.
Here is a parts list:
(2) 10-32 x 3" machine screws
(5) 10-32 x 1" machine screws, including fan electrodes
(8 ) #10 flat washers
(4) small rubber washers
(8 ) wire connectors (I used the ring type and not the fork type)
(13) 10-32 nuts
(1) fan, smaller than chamber (I used a 20mm in a 3" chamber)
(1) zip tie, long enough to go around fan
(1) half piece of 1" pipe, as long as chamber
(1) drill and bit the size of the screws
(1) hacksaw or dremel (dremel works better)
About an inch from one end, cut a notch in the sliced piece of pipe the same size as the fan. Drill a hole under each side of the notch. This is to attach the fan to the strip with the zip tie.
About an inch in front of the fan, drill a hole. Drill another about a half inch in front of that. Move up to where the center of your chamber is and drill another set of holes, then repeat about an inch from the other end of the sliced pipe.
Measure the length between the first and last hole drilled, and drill two holes through the chamber wall. Drill two more through the end of the chamber for the fan electrodes.
Make two pieces of wires with the wire ends. Assemble and shape screws as displayed in diagrams.
To adjust the spark gap lengths, simply tighten or loosen the appropriate screws. To close the gaps, tighten the screws until it touches the adjacent screws.
Try to make gap approximately 1/8". This should allow for any type of ignition source to be used.
I may have left something out (besides pictures; my camera crapped out on me. I'll post when I can).
If there are any questions, please ask.
Oh, and be sure to check out my hybrid spark system.
The way it's designed is to allow a spark in the rear, the middle, and the front of the combustion chamber. It has three gaps and each gap is fully adjustable (depending on screw length). The gaps can also be closed, allowing for just one or two sparks (for piezo igniters). It also has a built in fan, which is held in place by a zip tie, allowing it to be removed if necessary.
Here is a parts list:
(2) 10-32 x 3" machine screws
(5) 10-32 x 1" machine screws, including fan electrodes
(8 ) #10 flat washers
(4) small rubber washers
(8 ) wire connectors (I used the ring type and not the fork type)
(13) 10-32 nuts
(1) fan, smaller than chamber (I used a 20mm in a 3" chamber)
(1) zip tie, long enough to go around fan
(1) half piece of 1" pipe, as long as chamber
(1) drill and bit the size of the screws
(1) hacksaw or dremel (dremel works better)
About an inch from one end, cut a notch in the sliced piece of pipe the same size as the fan. Drill a hole under each side of the notch. This is to attach the fan to the strip with the zip tie.
About an inch in front of the fan, drill a hole. Drill another about a half inch in front of that. Move up to where the center of your chamber is and drill another set of holes, then repeat about an inch from the other end of the sliced pipe.
Measure the length between the first and last hole drilled, and drill two holes through the chamber wall. Drill two more through the end of the chamber for the fan electrodes.
Make two pieces of wires with the wire ends. Assemble and shape screws as displayed in diagrams.
To adjust the spark gap lengths, simply tighten or loosen the appropriate screws. To close the gaps, tighten the screws until it touches the adjacent screws.
Try to make gap approximately 1/8". This should allow for any type of ignition source to be used.
I may have left something out (besides pictures; my camera crapped out on me. I'll post when I can).
If there are any questions, please ask.
Oh, and be sure to check out my hybrid spark system.