PDA

View Full Version : igniter pre-fire time in CSC



Mattp
01-03-2020, 02:29 PM
hey guys.. working on my script for a pyromusical..using cobra show creator .. i am going to be using initiators and poking everything.. what do you normally set the igniter pre-fire time for... its default at .5 for initiators... but i feel it should be 0.0 ... any advice would be helpful

Robbro097
01-03-2020, 03:08 PM
Thats a good ? Iv been working on a pyromusical script as well and Iv been wondering the same thing. I currently am using .1 for direct items like dominator 62mm shells mines commets. And .3 for quick matched things like dominator slices and cakes but i have no idea whats best am really interested in seeing what some the pros on here do thanks.

Mattp
01-03-2020, 11:59 PM
i downloaded what i did so far and played around with it on the audiobox and remote....leaving it at .5 prefire time it sure seemed like everything fired exactly when i wanted it to..watching the countdown on the remote you really get to see how long a .5 of a second actually is.. but it still seemed to fire right where i wanted it to... good thing i still have 6 months to play around with it...LOL

krayg
01-04-2020, 03:12 PM
I used pre-fire times of 0.01 and 0.02 in my pyromusical with a combination of MJG initiators, dominator pro, and other consumer poked cakes. They all worked fine and you could probably get away with 0.00. I also used a 2.25 in the lift delay for the 62mm which was perfect.

Rick_In_Tampa
01-05-2020, 10:07 PM
I use 0 for everything with an initiator and 2 or 3 for anything with a talon.

Arclight
01-06-2020, 03:25 AM
Do e-matches and firewires have a "time to fire" specification? For reference, the zero-delay blasting caps I use for commercial blasting state in the documentation that they will fire within 9ms (.009 second) of being energized.

esgrillo
01-06-2020, 08:18 AM
zero firewire/ematch

Mattp
01-06-2020, 01:22 PM
thanks guys.. thats what i was thinking it should be be too (0)... but on the csc it recommends .02 for initiators .... and even though .02 of a second seems like nothing.. it can def make a difference when trying to get it perfect

PyroGyro
02-11-2020, 05:33 PM
I used pre-fire times of 0.01 and 0.02 in my pyromusical with a combination of MJG initiators, dominator pro, and other consumer poked cakes. They all worked fine and you could probably get away with 0.00. I also used a 2.25 in the lift delay for the 62mm which was perfect.

I've measured the lift time of the Dominator 62mms and most come in between 2.2 and 2.3 seconds so I'm not surprised that the breaks were timed perfect for you. As for prefire, Scott from Cobra did a test with ignitors in a poked tube and ignition took .1 (100ms) which is almost a negligible amount of time. I can't see why anyone would want a prefire time greater than that.

Matt- If you're setting igniter pre-ignition to .5 (1/2 second) and it's lining up with hits in your music track you must be getting lucky because a 1/2 second is a huge amount of time. It takes nowhere near that amount of time to fire a poked tube.

PyroGyro
02-11-2020, 05:44 PM
thanks guys.. thats what i was thinking it should be be too (0)... but on the csc it recommends .02 for initiators .... and even though .02 of a second seems like nothing.. it can def make a difference when trying to get it perfect

Where did you get this number from? The default in CSC is .1 (100ms) (see the preferences dropdown list, it doesn't even use two decimal places) and further, in a video made by Scott from Cobra he measured the time of an ignitor to a poked tube and it was 100ms to fire. .02 is 2/100ths of a second or 20 milliseconds. 20 milliseconds isn't even perceivable to human eye or ear. It's pretty much equivalent to 0. Last, I've spoken to Joel Robinson from Cobra about this as well and he recommended 0 lol. Bottom line is I think 0 or .1 is fine. Anything over that and you're overcompensating for the tiny delay that does exist with ignitors. Anything under .1 and you shouldn't see any difference between .1 and 0.

Mattp
02-21-2020, 12:56 PM
Where did you get this number from? The default in CSC is .1 (100ms) (see the preferences dropdown list, it doesn't even use two decimal places) and further, in a video made by Scott from Cobra he measured the time of an ignitor to a poked tube and it was 100ms to fire. .02 is 2/100ths of a second or 20 milliseconds. 20 milliseconds isn't even perceivable to human eye or ear. It's pretty much equivalent to 0. Last, I've spoken to Joel Robinson from Cobra about this as well and he recommended 0 lol. Bottom line is I think 0 or .1 is fine. Anything over that and you're overcompensating for the tiny delay that does exist with ignitors. Anything under .1 and you shouldn't see any difference between .1 and 0.

i was never to good at math..lol..i meant to say .2 ... but now i cant even find where i saw that recommendation... but i know i saw it somewhere that it recommended .2 for initiators... and .5 for talons... and yes.. i just set it to 0 anyway.. or i could even just take that column away all together

displayfireworks1
02-21-2020, 03:38 PM
Not sure if anyone noticed the delay in my last video using the breakout boards. I'm suspect if you are using the Cobra boards you would see a similar delay if firing multiple match. I think it may be best to pick a number a go with it. I know on professional displays in the past, I heard the match pop in the leader , then I heard the leader burn down to the lift, then strangely there is a noticeable delay before the shell comes out of the mortar.
.
Here are some videos I slowed down using the breakout boards.
.
You can start to see the delay occurring at this speed.
.

https://www.youtube.com/watch?v=5_icZleGTS8
.
.
Now a little slower
.

https://www.youtube.com/watch?v=eWiFgeQw0Ao
.
.
Here is the 6 match simultaneous and the same type of delay.
.

https://www.youtube.com/watch?v=534Fm6_BnnI
.
Does all of this mean anything? Should you compensate for it? Do you need to compensate for it? Now that we are moving into breakouts it is probably is something to consider particularly with a long run of CAT 5 cable.
.
.
Still shots.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=4774&stc=1
.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=4775&stc=1
.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=4776&stc=1

Arclight
02-21-2020, 05:06 PM
Are those slats series or parallel firing? If you're running a bunch of e-matches, you might want to try them in series, especially if your firing system allows you to run a higher voltage battery pack, like 12,24 or 48V. This is what you'd normally do on a blasting circuit.

Also, I don't know if this applies to larger pyro shows, but when you're setting off rows of boreholes with dynamite, you can get an additive sound effect if the shots are timed to around the speed of sound (about 3ms per meter). So you can product a gradually building wall of blast noise if pieces, say 10' apart are going off at ~9ms intervals.

Birdman
02-21-2020, 06:22 PM
Are those slats series or parallel firing? If you're running a bunch of e-matches, you might want to try them in series, especially if your firing system allows you to run a higher voltage battery pack, like 12,24 or 48V. This is what you'd normally do on a blasting circuit.

I'm going to guess they are parallel because I didn't see a shunt.

displayfireworks1
02-21-2020, 07:28 PM
I'm not sure what they are in reference to series or parallel. I know they are numbered on the boards. You guys that know this sort of thing, if I posted close up pictures of a board would you be able to tell by looking at the circuitry? I'm currently rendering a video I'll post tonight. I tried to mix the 6 shot board with a 12 shoot board from another CAT 5 system out of the UK. Some of it did not go as planned and some of it did not.

Instead of me using electric match trying to figure these boards out on different systems, I need some LED lights. Can someone recommend an Ebay link to some LED lights I can use in place of electric match. I'll need about 50. I had some once and now I can't find them.

cptnding
02-21-2020, 09:08 PM
I'm not sure what they are in reference to series or parallel. I know they are numbered on the boards. You guys that know this sort of thing, if I posted close up pictures of a board would you be able to tell by looking at the circuitry? I'm currently rendering a video I'll post tonight. I tried to mix the 6 shot board with a 12 shoot board from another CAT 5 system out of the UK. Some of it did not go as planned and some of it did not.

Instead of me using electric match trying to figure these boards out on different systems, I need some LED lights. Can someone recommend an Ebay link to some LED lights I can use in place of electric match. I'll need about 50. I had some once and now I can't find them.

Cobra sells them:
https://www.cobrafiringsystems.com/bulb_test

I've got 20 of them around here somewhere that I don't need anymore. You can have them if you want. PM your mailing address and I'll send them your way.

Arclight
02-21-2020, 11:39 PM
If you post a closeup of the front and back of the circuit board, there should be several of us who can tell who what the circuit does.

Regarding the LEDs: The way to simulate a single cap or e-match is with a 2ohm resistor. So if you want to see how many e-matches you can set off in series, you would put those resistors and series, together with one real e-match and then fire. If the one e-match fires, you should be good to go.

You can probably do the same with a parallel circuit, although it's not completely the same as using real initiators.

If you want LEDs to light up, we need to know the firing voltage first.

Mattp
02-22-2020, 10:56 AM
I don’t know but I would think unless otherwise specified they would be made in parallel.. to me that just makes more sense.. and with those vids in slo mo.. that is really cool your actually seeing the speed at which electric is traveling through the wires.. I get that in my living room with my LED recessed lights... the ones closer to the power source go on first... it’s all within a second of each other.. but is visibly noticeable

PyroGyro
02-23-2020, 02:13 PM
There's a clear delay in the videos between the ematch/breakout boards but the question is, is the delay perceivable but the naked eye when the video is played full speed?

Arclight
02-23-2020, 04:29 PM
The delay between boards is probably because:

1. The voltage drop between each slat is different due to there being a CAT5 cable in between. So it's actually a series-parallel circuit at that point. The electric match bundle on each board is in parallel, but each board is fed by a length of 22-28ga wire that adds a different series resistance to it than the previous one.

2. As the matches fire, more current is available to heat up and fire the later ones.

Analyzing a circuit where all of the items are in series is pretty easy. The voltage drop across each is the same and they all get the same amount of current. Parallel and series-parallel can get complex fast. They make you learn all of this for the blaster's exam here, and then they tell you to just use series whenever possible unless you are firing from a big power source like a generator.


There's a clear delay in the videos between the ematch/breakout boards but the question is, is the delay perceivable but the naked eye when the video is played full speed?

displayfireworks1
02-23-2020, 06:29 PM
Here are some pics of one of the boards, front and back.
.
.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=4784&stc=1
.
.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=4785&stc=1
.
.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=4786&stc=1
.
.
http://www.pyrotalk.com/bulletin/attachment.php?attachmentid=4787&stc=1

Arclight
02-24-2020, 12:12 AM
Okay, this board gives you (6) separate firing circuits. The red/positive terminals are all wired together and fed by (2) wires out of the 8-wire CAT5 bundle. The other 6 are individual circuits. If you hook up another one of these from the second jack, you will have the same 6 cues, place in parallel with the ones on the first board.

So two boards daisy chained with CAT5 cable gives you 6 cues that fire two items per cue, one at the first board and the other at the second one, in a parallel circuit.

esgrillo
02-24-2020, 10:49 AM
Okay, this board gives you (6) separate firing circuits. The red/positive terminals are all wired together and fed by (2) wires out of the 8-wire CAT5 bundle. The other 6 are individual circuits. If you hook up another one of these from the second jack, you will have the same 6 cues, place in parallel with the ones on the first board.

So two boards daisy chained with CAT5 cable gives you 6 cues that fire two items per cue, one at the first board and the other at the second one, in a parallel circuit.

Cobra sells series and parallel versions of this board

pyrobeef
02-25-2020, 11:01 PM
Instead of me using electric match trying to figure these boards out on different systems, I need some LED lights. Can someone recommend an Ebay link to some LED lights I can use in place of electric match. I'll need about 50. I had some once and now I can't find them.

I have used these LED's from Lighthouse (sold on Ebay). I have tested a few shows now and they work great. I tried some cheaper ones originally, but they would burn out after one or two uses. I have not had any issues with these LED's yet, and I have probably completed 30 total dry runs with them. They come in a variety of colors and package sizes. I would recommend them for sure!

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=led+12v+5mm+internal+resistor

Arclight
02-26-2020, 01:18 AM
Those come with a built-in resistor, so should be good for many uses. Regular LEDs don't want more than about 3V without a resistor.

displayfireworks1
02-27-2020, 09:31 PM
I have used these LED's from Lighthouse (sold on Ebay). I have tested a few shows now and they work great. I tried some cheaper ones originally, but they would burn out after one or two uses. I have not had any issues with these LED's yet, and I have probably completed 30 total dry runs with them. They come in a variety of colors and package sizes. I would recommend them for sure!

https://www.ebay.com/sch/i.html?_from=R40&_trksid=m570.l1313&_nkw=led+12v+5mm+internal+resistor

Thanks for that advice on the ones with resistors. I just purchased some to give them a try.