mguerra
12-06-2013, 03:32 PM
The Sequencefire 32 system allows you to set a different time delay between every cue. You push one button to start the sequence and all the cues fire in order automatically with your defined time delays between cues. So I set up a show that alternated cakes with mortar racks. The cake timing is easy to get from videos. To time the mortar racks I simply measured the length of fuse and multiplied it times the seconds per minute fuse speed. So for example for a ten shot mortar rack that uses a 24 inch piece of fuse that burns at 30 seconds per foot should take 60 seconds to burn. So I programmed all my cues according to this concept. All the mortar racks went off much faster than I calculated, and not from pre-ignition. Watching Dave's videos of how black match becomes quick match when encased in a paper tube, I got an idea. I wondered if the visco fuse would speed up like this when wrapped in masking tape to the shell fuses. This was all Excal cans by the way. So i just went out side and took some 30 second per foot visco fuse and masking taped it to some pieces of the Excal fuse exactly like I fuse up a rack. When I lit it, the first part of the visco burned at normal speed until it hit the first masking tape junction to the shell fuse. As soon as the fire got in to the masking tape, it shot forward like quick match! Then when it got to the end of the tape it burned normal speed until it hit the next taped junction and flashed ahead at light speed through the tape, as before. So the visco fuse burned along the 24 inch segment at about double speed. So my ten shot, 24 inch mortar rack that I thought would take 60 seconds to go off, went off in about 30 seconds roughly. So in my show, every time a mortar rack went off, it went off way faster than I calculated and there was a huge delay before the next cue went off! If you are shooting your show by pushing one button per cue as soon as the previous cue finishes this is no problem. But if you are programming a timed sequence using Sequencefire or Cobra or any other programmable device, you need to know exactly how fast your fused racks are going to fire. It won't be the fuse length times the seconds per foot! You might want to go out and fire a test rack of every type of rack you will shoot in your show, using the fuse you will use in your show; and time it. Alternatively you can set up a test piece of fuse, tape it to pieces of shell fuse, at the exact spacing of your mortar tubes and exactly the length of your rack(s), and fire that off and time it. My show timing was totally screwed up by this phenomenon. So yes, visco fuse taped to shell fuses speeds up a lot like quick match. Be aware.