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Bitzan
10-30-2020, 05:39 PM
Friends,
What is the consensus lift time on these shells? Looks to me to be close to 2 seconds perhaps slightly less?
Thanks,
John

tmwjr
10-30-2020, 06:03 PM
I live by 2.25 seconds in cobra show creator. The effects hit pretty darn close. Watch the 3 shells at 1:09 for an example.

https://youtu.be/qlUM-ZTKgdU

https://www.youtube.com/watch?v=qlUM-ZTKgdU&feature=youtu.be

Salutecake
11-01-2020, 06:13 PM
Hey tmwjr, I'm just getting started with the cobra show creator, so you show above, which by the way is great!, 2.25 seconds for 3 inch shell in general or are you talking about 2.25 seconds for Dominator stuff?

tmwjr
11-01-2020, 09:25 PM
Thank you!

I apologize for putting 3 inch shells in the initial post. I will try and edit it. It should have said 62mm. I use 2.25 seconds (and 0 prefire) for 62mm and (3'') NOABs (poked). The nishiki shots in the into were from the NOAB Mother of All Bombs (poked on the third tube). It broke right when it was supposed to.

For 1.3 product I use the link below. Budget shells seem to break a bit earlier in my humble experience. The last shot in the video was a 10'' that broke pretty close to when it was supposed to but a slightly early.

https://www.skylighter.com/blogs/fireworks-information/aerial-shell-making-charts

Tom

Salutecake
11-02-2020, 11:28 AM
Thanks tmwjr the clarification! Do you find for the 1.3 stuff -- according to the charts from above and using cobra show creator that 3sec for 3" and 3.5 for a 4" is about right? .I know it's not going to be perfect but I will be doing some test shots soon and was just looking for a place to start, timing wise.

tmwjr
11-02-2020, 10:17 PM
I have not tried to perfectly time any 1.3 3'' or 4'' shells. Maybe someone else can chime in too.

For that show, I scheduled 4'' shells about .5 second behind other effects because I did not trust the lift times on the shells honestly. I used budget 4'' shells for that show. I shot them before and knew that they did not go the expected height. They look super low in the video because 1) they were cheap 2) they were set 500' back to save on runs of wire back to the 8'' and 10'' that were set at 700' away 3) the GoPro was on super wide.

I attached an excerpt from the script. The 4'' that is listed was supposed to break about .5 second after the brocade fan shot, but it broke at the same time. So that lift time was off by a whole .5 second. Which is what I tried to compensate for by delaying it a bit. I think that fancy shells would have been more accurate. I would like to hear other people's thoughts on this too. If you want to take a look, it occurs just after 2:25 in the clip of the show.

Testing and recording the exact product is a good idea. For exact timing, for me it is easier to time the 2'' cakes (about 2 seconds), 62mm (2.25 seconds), and slices/single shots. It is nice to hide timing issues of aerials behind fans cakes, slices, and single shots.

Next year I am going to try and time some 5'' pattern shells and 4'' fancy shells. We shall see how it goes.5308

joed2323
12-23-2020, 08:59 PM
Thank you!

It should have said 62mm. I use 2.25 seconds (and 0 prefire) for 62mm and (3'') NOABs (poked).
Tom

So you only use lift time and not prefire time? Sorry if I misunderstood

Why not use a prefire time?

What scripting software do you use, just wondering?

tmwjr
12-26-2020, 09:28 PM
So you only use lift time and not prefire time? Sorry if I misunderstood

Why not use a prefire time?

What scripting software do you use, just wondering?

With the 62mms I only use the lift time. I figure with the igniter right into the lift it doesn't matter that much. With the 1.3 shells I add a prefire (.1) because of the QM. I've just never tried to hit those perfectly on a note or anything. I timed 1 10 decently at the very end of the video. The 62mm lift is very predictable in my experience. I had a case of blue peony 62mms barely lift out of the tube, fall to the ground, and detonate after about 2.25 seconds.

I'm open to all suggestions for sure. I'm relatively newer to the timing world.

I use cobra show creator. I add the lift time to the product in the database.

Please tho, any suggestions are appreciated.

Birdman
12-27-2020, 12:17 PM
Prefire time is to allow for the time it would take to fire the shell, cake etc. For example if using talons, you need to account for the time it takes for the talon to light the fuse and the fuse to burn before the lift charge etc is ignited. Lift time is to account for the time it takes a shell to reach its apogee before the burst charge is ignited, firing the effect. So if you're scripting an unmodified (not poked, quick matched etc) single shot consumer tube and want that shell to burst at a specific time in your show, you would need to account for the time it takes for the fuse to burn after the cue is fired (prefire) and then the time it takes for the shell to get in the air (lift time) and then burst.

Lets say you want that shell to burst at 2:30 into your script and it takes 10 seconds (prefire) for the fuse to light the lift charge and then 1.5 seconds (lift time) for the shell to get in the air and burst, your cue would actually fire at 2:18:5 seconds into the script even though the the event was scripted in Cobra Show Creator at 2:30. If you didn't account for prefire or lift time the cue would fire at 2:30 but the shell would burst at 2:41:5, much later than you wanted it to. The CSV you load into the 18R will have the adjusted time that accounts for prefire and lift times. Of course a lot of this is all guess work and best you can hope for is getting close to that shell bursting at 2:30 as you want it.

Most people that instant fire (poke) cakes etc don't use prefire because there is none when instant firing. Lift time is a different story and I've heard of some people using lift time and others that just script the event in CSC a tad early to account for lift rather than putting in any lift time. I use lift time for shells but avoid even scripting these where I want precision because there are too many variations to get the timing exact. Where I want precision I prefer to script comets or something with tails and then hope to get lucky with shells firing when I want them. Like so many things pyro, there is no right or wrong way. It comes down to what works best for you.