Newbie pyro with some questions on timing

[ajmikola]

Hello all,
I am currently doing my 3rd straight fireworks show for my neighborhood. The past 2 years my budget has been 1500$ and looks to be the same this year. Over the past two years i have created cake boards and a few mortar racks, but like everyone else, I am trying to step it up.
It is too late this year to buy an E-firing system, so I am going to be hand firing my boards this year.

Last year I had a real problem with timing because i randomly wired everything up using slow fuse. There was quite a bit of time between cakes.
As such, this year I have really been researching timing and have come to find (at least from what everyone is saying) that it is a crap shoot.

With that said,
This year i have perfect fuse, fast artillery fuse, and medium cake fuse. If i want to have a show with minimal down time i need to:
1. Watch the videos for timing
2. Measure and test fuse speed

However, how do i know how far to distance the cakes on the board and how much fuse do i put between cakes. For example, if cake 1 is 24 seconds and cake 2 is 28 seconds, how do I know how much fuse between them so cake 2 is starting as cake 1 is ending?

I hope I don't sound too much like an idiot. Its not really specific timing I am looking for as much as it is the cakes are coming off the back of each other for continuity. Thanks in advance.

[Mississippipyro]

I did all fused cake boards for many years. The key for me was:
1. Test the fuse, lots of variability between lots)
2. Watch lots of video as new as possible, timing can change year to year.
3. Measure out the fuse for timing, (for example if a cake is 30sec I measured I used 3’ of perfect fuse @ 10 sec a foot) I also overlapped a bit to eliminate black sky
This should work well

[BeerGuyEd]

When I run out of ques for my firing system and have to resort to fusing cakes together I always just poke the last tube of a cake and run fuse to the first tube of the next cake. That has worked well for me in the past.

[PyroGyro]

The different fuse types burn at so many inches per second so this will be part of your calculation and you will need to know the burn rate (inches per second) of your connecting fuse in order to properly calculate how much of this fuse you'll need between cakes.

Furthermore, the green visco fuse built into the cake needs to be factored into the calculation as well because this itself needs to be counted. When I used to fuse cakes together I would assume it took 5 seconds for the green visco on the cakes to burn before the cake would fire. So use 5 seconds as a number for all your cakes built in cake fuse.

Here is an example of how to calculate how much fuse between cakes you need.

Let's assume that you have 2 cakes fused together and the first is 30 seconds long and you want the next one to fire right after the first one. Let's also assume for example purposes that the burn rate of the connecting fuse between the cakes is 1ft of fuse for every 10 seconds. This means that this fuse burns at 1.2 inches per second or (12"/10secs)= 1.2 inches of fuse per second.


Since your first cake takes 30 seconds to shoot you need 30 seconds of connecting fuse - 5 seconds of 2nd cake built in fuse to have the 2nd cake start at the right time. So you need a total of 25 seconds of connecting fuse between cakes. In the above example the connecting fuse burns at 1.2 inches per second. You need 30 inches of connecting fuse run between your 2 cakes in order to be around 25 seconds, and then when you add in the 5 seconds for the built in cake fuse you're now at 30 seconds between cakes.

[ajmikola]

The different fuse types burn at so many inches per second so this will be part of your calculation and you will need to know the burn rate (inches per second) of your connecting fuse in order to properly calculate how much of this fuse you'll need between cakes.

Furthermore, the green visco fuse built into the cake needs to be factored into the calculation as well because this itself needs to be counted. When I used to fuse cakes together I would assume it took 5 seconds for the green visco on the cakes to burn before the cake would fire. So use 5 seconds as a number for all your cakes built in cake fuse.

Here is an example of how to calculate how much fuse between cakes you need.

Let's assume that you have 2 cakes fused together and the first is 30 seconds long and you want the next one to fire right after the first one. Let's also assume for example purposes that the burn rate of the connecting fuse between the cakes is 1ft of fuse for every 10 seconds. This means that this fuse burns at 1.2 inches per second or (12"/10secs)= 1.2 inches of fuse per second.


Since your first cake takes 30 seconds to shoot you need 30 seconds of connecting fuse - 5 seconds of 2nd cake built in fuse to have the 2nd cake start at the right time. So you need a total of 25 seconds of connecting fuse between cakes. In the above example the connecting fuse burns at 1.2 inches per second. You need 30 inches of connecting fuse run between your 2 cakes in order to be around 25 seconds, and then when you add in the 5 seconds for the built in cake fuse you're now at 30 seconds between cakes.

Exactly what I was looking for. Thank you.

[N.E. Pyrotechnics]

It's time to learn how to "chain fuse" your cakes. You will not be disappointed. It would be a lot easier, and I recommend poking and fusing before glueing them up. There are other discussions here, and our wonderful host, Dave, has an excellent tutorial on his channel. Make sure you are using a non-ferrous metal for your poke (brass, bronze, copper ). You can purchase a device made for this job. I'm not sure if they advertise here or not, so you will have to employ your Google skills, or maybe someone who knows here in the forum could pass it on. I made my pokes with materials I bought at my local hardware. I used .250" & .375" brass round stock. I found with the hardware, in the threaded rod display. Found handles for files that had a similar sized opening to accept the tang of the file. Cut the rod to length, work one end to a point, it doesn't need to be sharp. Glue the piece into the file handle.
Learning this technique will up your game, in my opinion. This if done properly, will eliminate any "dark sky" moments. I'm only shooting my second show this Fourth, but one thing I learned long before ever shooting a show, was how unintended dark sky can ruin the flow of an otherwise good shoot. Just my freshman opinion here.
Be safe, and have a great show, and a great Fourth!

[rfgonzo]

Like other have said. If your comfortable poking cakes it takes a lot of the guess work out. You can use quick fuse leading from first tube with visco then poke the last tube and run quick fuse to next cake. Lots of videos on youTube.

[ajmikola]

It's time to learn how to "chain fuse" your cakes. You will not be disappointed. It would be a lot easier, and I recommend poking and fusing before glueing them up. There are other discussions here, and our wonderful host, Dave, has an excellent tutorial on his channel. Make sure you are using a non-ferrous metal for your poke (brass, bronze, copper ). You can purchase a device made for this job. I'm not sure if they advertise here or not, so you will have to employ your Google skills, or maybe someone who knows here in the forum could pass it on. I made my pokes with materials I bought at my local hardware. I used .250" & .375" brass round stock. I found with the hardware, in the threaded rod display. Found handles for files that had a similar sized opening to accept the tang of the file. Cut the rod to length, work one end to a point, it doesn't need to be sharp. Glue the piece into the file handle.
Learning this technique will up your game, in my opinion. This if done properly, will eliminate any "dark sky" moments. I'm only shooting my second show this Fourth, but one thing I learned long before ever shooting a show, was how unintended dark sky can ruin the flow of an otherwise good shoot. Just my freshman opinion here.
Be safe, and have a great show, and a great Fourth!

Very interesting.....will look into it. Thanks!