Average lift time for 60g cans?

[Birdman]

I know this must be posted out there somewhere but I just can't seem to find it. I know it won't be exact because every shell could be slightly different....but what should I estimate for the lift time of the typical 60g canister shell? Looks to be in the 2-3 second range from the time the lift charge fires until they break. Anybody have an average time they use?

As of right now the plan is to replace the green visco with fast fuse. If I account for fuse burn rate in my lift time (using CSC BTW), I'm thinking 3 seconds might be the closest...thoughts?

[tonyr]

I would say 2 seconds from lift charge firing to break but total time will be dependent upon your fusing and obviously the shells so really just comes down to the burn rate of your replacement fuse. Good estimate IMO. I am just an amateur though so take my words with a grain of salt.

[Jay_]

1.8 is what I use, but that’s poked not fused.

To be completely honest, if you are requiring precise timing...you are just not going to get there with fuse.

Speaking from lots of trial and error experience here.

[Birdman]

Thanks for the responses. I don't expect precision but something relatively close and from there hope to get lucky. Next year I will be using 1.4g Pro single shot tubes where I want it to hit at just the right time. Maybe I'll poke and go with the 1.8s lift time instead. I have to admit that poking a can makes me a little nervous.

[PyroKing31]

Thanks for the responses. I don't expect precision but something relatively close and from there hope to get lucky. Next year I will be using 1.4g Pro single shot tubes where I want it to hit at just the right time. Maybe I'll poke and go with the 1.8s lift time instead. I have to admit that poking a can makes me a little nervous.

It's not any more risky than poking a cake. You have 2 seconds to toss the live grenade if anything goes wrong.

[Jay_]

The cans used to bother me, but after doing several hundred of them over the last few years I don’t sweat it anymore.

That’s certainly not to say that I don’t respect what could happen, but I also understand that if I do things the right way with the right tools the risk is very slight. If you have a good setup, 1.8 seconds is plenty of time to swipe it away from you, take your escape route, and take cover should something happen.

[rfgonzo]

I go with 1.2 but that's poked and MJG fired.

[N.E. Pyrotechnics]

Sorry if it has been discussed elsewhere, but why are you poking cans? I only have experience with a handful of different brands, but every can or ball shell that I have e-fired, I have introduced the initiator to the lift by a small hole, or cut in the disc, or whatever construction on the bottom of the shot. Is there some benefit in poking vs. my method?

[Jay_]

Doubt that anyone is literally poking cans. Just a short way to say that you are shooting your cans off an igniter placed in the lift rather than using fuse.

[rfgonzo]

https://youtu.be/TZthkPvKrDY

https://www.youtube.com/watch?v=TZthkPvKrDY&feature=youtu.be

[topshelfpyro]

It seems more like 1.5 seconds from lift to break for most of the cans that I shoot. I wish it was 2+ seconds, I prefer higher bursts.

[Birdman]

I did a test this past weekend with a wired can. I pulled the visco and poked it on the bottom. Inserted my MJG and taped it up. I didn't tape the wire to the can like in Dave's video. I'm not sure why that would be needed (other than making sure you don't confuse top from bottom?). I think one would want the wire to separate as cleanly as possible and taping it to the can would mean you would need to use energy from the lift charge to rip the wire/tape from the can. I assume the energy needed to rip the wire from can is minimal with the forces at play but it seems unnecessary to me. Any thoughts?

After reading suggestions of 1.2 and 1.8 seconds I decided to use 1.5 seconds for my test and that was close enough for me.

[rfgonzo]

I always use tape. There is so much force and pressure coming out of the mortar tube a piece of tape and wire isn't going to slow it down.

[displayfireworks1]

I did a test this past weekend with a wired can. I pulled the visco and poked it on the bottom. Inserted my MJG and taped it up. I didn't tape the wire to the can like in Dave's video. I'm not sure why that would be needed (other than making sure you don't confuse top from bottom?). I think one would want the wire to separate as cleanly as possible and taping it to the can would mean you would need to use energy from the lift charge to rip the wire/tape from the can. I assume the energy needed to rip the wire from can is minimal with the forces at play but it seems unnecessary to me. Any thoughts?

After reading suggestions of 1.2 and 1.8 seconds I decided to use 1.5 seconds for my test and that was close enough for me.

I tape the wire next to the fuse path to stabilize it and use the wire to drop the shell. You do not need to unravel the fuse , just drop it. Assuming you are using a Cobra , you still need to tie off the match wire on the rack so it does not pull at the Cobra when it lifts. You can do it your way also but its an awkward drop into the mortar and necessitates unraveling the fuse to hold during the drop.
As far as fuse timing/reaching apex etc, remember Consumer Fireworks are not built to exacting specifications for timing. This is where AP products come in to play , when timing is critical. For Consumer product just go with an average

[Salutecake]

The other point about taping, is that you are going into the lift charge, and if by chance you spill any of the lift out you are going to have low breaks or perhaps even a flowerpot.

[Birdman]

I tape the bottom where I poke to seal in the match and lift charge. I didn't tape the wire to the side of the can like Dave does. I don't think it matters much one way or the other. My only concern was having it taped at two points means your using lift energy to pull the wire off at two spots. I had no problem loading them but I guess everything would be more stable when loading with the wire secured at two spots (bottom and side) like Dave says. I've been meaning to do a side by side test with one can taped only where it's poked and one with the wire taped to the side as well to see if there is any difference in height. Honestly I think the differences are trivial. Like Dave says....you need to tie off your wire in either case to keep the wire from pulling on your module.

However, I'm thinking twice about not pulling the fuse out because I had one can not fire. To make a long story short, I ended up pulling the fuse and lighting it that way. It would have been much better if I didn't have to pull the fuse out to light it. So from now on I may pull the fuses in the event this should happen again.

[BMoore]

I poke the bottom of the lift. It's easier and quicker since you are going through thinner material than the side. I use a little piece of tape to seal the hole. I don't worry about tying off the wire since the bottom of the lift cup blows out entirely leaving nothing to drag the wire up. I'd also think this method allows the shell to go a bit higher since momentum isn't being lost pulling out the wire. Depending on how much time I have I like to go ahead and unravel the visco just to have an easily accessible light point if a match fails.

[topshelfpyro]

I poke the bottom of the lift. It's easier and quicker since you are going through thinner material than the side. I use a little piece of tape to seal the hole. I don't worry about tying off the wire since the bottom of the lift cup blows out entirely leaving nothing to drag the wire up. I'd also think this method allows the shell to go a bit higher since momentum isn't being lost pulling out the wire. Depending on how much time I have I like to go ahead and unravel the visco just to have an easily accessible light point if a match fails.

I personally don't like poking the bottom. If your removing the safety shroud from the match as you see in videos, but is warned against by almost everyone including the manufacture, it may not matter. With that being said, you run the risk of surrounding the time fuse with the match shroud accidently and not lifting at all, where as from the side that would be impossible.

[BMoore]

I personally don't like poking the bottom. If your removing the safety shroud from the match as you see in videos, but is warned against by almost everyone including the manufacture, it may not matter. With that being said, you run the risk of surrounding the time fuse with the match shroud accidently and not lifting at all, where as from the side that would be impossible.

I leave the shroud on. Never really thought about it before but I go in at kind of an angle to keep from forcing the match through the BP of the inverted shell. So once done the match is basically laying sideways on the bottom of the shell.

[Birdman]

I angle the shroud too. When I first tested poking cans (bottom) I didn't tie the wires off and there was no noticeable pulling on the module. I also showed my son how to poke a can and fired it with a 9v battery. I did feel a slight tug on the wire I was holding. This made me decide to tie the wires off for my show even though I didn't think there was enough force to effect the module. Not worth taking the chance of ruining a module or a show.

[topshelfpyro]

I leave the shroud on. Never really thought about it before but I go in at kind of an angle to keep from forcing the match through the BP of the inverted shell. So once done the match is basically laying sideways on the bottom of the shell.

Yea makes sense. I just poke where the fuse is, like a cake I guess. Whatever works best for you I think.