db5086 Posted December 22, 2014 Posted December 22, 2014 If I split my time fuse for cross matching should the length of the cut be added to the length of the fuse in order to get the correct delay before the shell breaks. This is in consideration that fuse, lift and shells are finally consistent. I think my shells are breaking a bit soon.
calebkessinger Posted December 22, 2014 Posted December 22, 2014 (edited) Yes, measure your delay and then add whatever depth of cut you like to use to that. Whatever fuse is past the cross-matching is just used to hold the black match into place and theoretically the shell has already burst before this lights. Edited December 22, 2014 by calebkessinger
dagabu Posted December 22, 2014 Posted December 22, 2014 Indeed, the timing is maintained between the cross matching, in the drawing below, the distance from match to match determines the timing. http://www.pyrouniverse.com/crossmatch.gif
Arthur Posted December 23, 2014 Posted December 23, 2014 Yes it's the closed column of powder that times.
fish7days Posted January 10, 2015 Posted January 10, 2015 If you use a razor blade with a reinforced back, the cut will be half an inch from blade edge to the reinforced edge. Half an inch either side - just add an inch to your timed length. Makes the math easy.
AldoSPyro Posted January 10, 2015 Posted January 10, 2015 Indeed, the timing is maintained between the cross matching, in the drawing below, the distance from match to match determines the timing. http://www.pyrouniverse.com/crossmatch.gifHey Dagbu great graphic! I think I saw you at the pgi 2014 convention in mason city, you are David Gustafon right? I saw you at the sign up desk at the manufacturing area at the pgi.
db5086 Posted January 10, 2015 Author Posted January 10, 2015 I do indeed use a single edge razor blade to split the time fuse. I put up several shells on NYE with the longer fuse but I'm only cross matching the lift end. The shell side is feeding into a pass fire tube filled with strands of black match. I think the breaks looked much more symmetrical and very close to apogee so I thank you all for the input. Out of curiosity, why cross match the inside end of the time fuse. Does this speed up or aid in the distribution of fire to the break charge? I would put up a video for critique but I'm not comfortable with youtube.
Shadowcat1969 Posted January 15, 2015 Posted January 15, 2015 You cross match the inside for basically the same reason as the outside, but in reverse. The fire taking (outside) of the fuse because the face of exposed powder in the core just isn't very large, even with a diagonal cut, and can fail to take fire. By the same token, the fire giving (inside) face is also small and MAY not always spit enough fire to ignite the strands of match you have in the tube. It's just an insurance policy.
dagabu Posted January 15, 2015 Posted January 15, 2015 Hey Dagbu great graphic! I think I saw you at the pgi 2014 convention in mason city, you are David Gustafon right? I saw you at the sign up desk at the manufacturing area at the pgi. Indeed I was! I had a table and served as the co-chair for the Super String as well. Funny lookin face nowadays but I'm still kickin!
FlaMtnBkr Posted January 17, 2015 Posted January 17, 2015 ...I'm still kickin!That and your great attitude are what matters. Well, that and a loving family and friends. Most other things are minor details.
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