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Ignitor; No Joy

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Sluggo

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Today I had a rocket on the pad and when I hit the go buttons..... Nothing. So I waited a short while, took it off the pad and re-seated the ignitor. 2nd try no go again. Repeated..... 3rd try, nothing. F32-4T motor by AeroTech. It's obvious the ignitor would not fire. Everything looked fresh on the wires. When I got home I torched the ignitor with a bic and flash..... Fire. Any idea what was not working.?? The controller had new batteries and operated great. I set the motor and ignitor aside with a note, loaded up another motor and flash..... Lift off.
 

heada

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What controller, what battery, what wires from the controller to the pad (kind and size) and confirmed no short on the starter leads?

Starters need a minimum amount of energy to start and even with fresh batteries, if they're too low voltage, too high internal resistance, the wires too thin or too long, the controller can't deliver the minimum required energy.

You can mitigate some things like using thicker stranded wires, using higher voltage and/or a battery with low internal resistance. Some controllers allow this easier than others.
 

Sluggo

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What controller, what battery, what wires from the controller to the pad (kind and size) and confirmed no short on the starter leads?

Starters need a minimum amount of energy to start and even with fresh batteries, if they're too low voltage, too high internal resistance, the wires too thin or too long, the controller can't deliver the minimum required energy.

You can mitigate some things like using thicker stranded wires, using higher voltage and/or a battery with low internal resistance. Some controllers allow this easier than others.
In all due respect did you miss the part that I reloaded and the rocket went high. ??

The controller is an Estes Pro Series II. 6 New Duracell C batteries. No shorts. I had continuity on all 3 tries. 30ft. of wire. Don't know what size. I love the controller. Its actually quite nice. The additional 2 clips were rolled back and clipped onto the rubber/insulation. I had 5 flights on motors E and F in size. One bad ignitor. I think. What say you.??
 

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cerving

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Aerotech igniters take 12V and more current than those 6C batteries are going to put out, especially with the skinny wire on that controller. Aerotech makes a launch controller, you might want to see if your local hobby shop has it (if they carry Aerotech...)
 

Jay Rairigh

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Did you look closely at the wires immediately before the pyrogen? It could have been shorted out there and you would still get continuity.
 
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BEC

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Cris,

I have fired the infamous Copperheads with the PSII controller. The wire is at least 18 gage, possibly 16.

Granted, it’s even better with a 3s LiPoly in it, but 6 Duracells should be able to fire one Aerotech igniter of most any sort they currently make.

I like Jay’s thought.
 

Sluggo

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Aerotech igniters take 12V and more current than those 6C batteries are going to put out, especially with the skinny wire on that controller. Aerotech makes a launch controller, you might want to see if your local hobby shop has it (if they carry Aerotech...)
It's not skinny wire. It's heavy. Estes description is ''Heavy duty cable." I've had 1 ignitor not go. Not going out to buy another controller. Let's see how this controller performs down the road. As I said previously, I like this controller. The hobby shop has the controller you speak of. I've done a lot of soldering. I hate it.
 

Sluggo

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Did you look closely at the wires immediately before the pyrogen? It could have been shorted out there and you would still get continuity.
Like I said, no short. I'm real careful about that. I stripped all the wire once I got home to see if there were any gaps. In one spot the wire broke. Seemed like a weak spot but I can't be certain so I'll withhold judgement.
 

Sluggo

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Cris,

I have fired the infamous Copperheads with the PSII controller. The wire is at least 18 gage, possibly 16.

Granted, it’s even better with a 3s LiPoly in it, but 6 Duracells should be able to fire one Aerotech igniter of most any sort they currently make.

I like Jay’s thought.
Thanks for the confidence in the controller. Like I've said, I like the controller. A lot. We'll see how it holds up.
 

heada

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Ignigters have an all-fire rating (will always ignite) and a no-fire (will never ignite) rating. You want to be at or below the no-fire for continuity circuit and at or above the all-fire when hitting the "go" button. You're obviously somewhere between them for an AT igniter using your setup. Tip the scales to your side by swapping the 6x 1.5v C batteries for 1x 4s 50c lipo battery. The C batteries can only deliver a few amps at 9v whereas the lipo battery will be able to deliver more than 20 amps at 14.4v. The higher voltage lowers the losses due to the thin wire (and it's thin for HPR type uses) You could also use a 12v SLA battery but they're much bigger and heavier than a lipo.

Good luck.
 

llickteig1

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Sometimes ignitors are bad, even if not burned. Get another and move on. The best test is with an ohmmeter, not a lighter. Bad pyrogen is generally not the problem, short or open circuit is. It varies between types, but somewhere around 1.5 ohms is typically good. Zero or infinity is bad.
 

David Schwantz

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Actually, it sounds like you got some of Aerotech bad ignitors. There have been several that have come with no compound, broken wiring, shorted out wiring. I did a thread a while back about this. Several others came forward with the same problems. If you do a search, take a look at the pics and see if yours look like any of them. Good luck with future flights,
 

RalPh8

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Ignigters have an all-fire rating (will always ignite) and a no-fire (will never ignite) rating. You want to be at or below the no-fire for continuity circuit and at or above the all-fire when hitting the "go" button. You're obviously somewhere between them for an AT igniter using your setup. Tip the scales to your side by swapping the 6x 1.5v C batteries for 1x 4s 50c lipo battery. The C batteries can only deliver a few amps at 9v whereas the lipo battery will be able to deliver more than 20 amps at 14.4v. The higher voltage lowers the losses due to the thin wire (and it's thin for HPR type uses) You could also use a 12v SLA battery but they're much bigger and heavier than a lipo.

Good luck.
Excellent answer.
 

Sluggo

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I like David's reply above. Thats what I did. I grabbed another ignitor and the rocket went high. In all due respect, anyone can speak numbers and get all rocket science over it. It was a bad ignitor. So honestly, numbers mean nothing to me. I'm not buying that theory. The controller set up is NOT failing on every other flight. It works. Just not on 1 ignitor. If your toilet doesn't flush on the first try are ya gonna buy a new toilet.??

Heada...... How many amps does 6 C batteries produce.?? How many amps does an ignitor need to fire.?? And you say "a few amps at 9v." Can you put a number on that the same way you did with a LiPo.??
 

ThirstyBarbarian

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Was this the only igniter of its type (brand and model) you used? If your controller can light other igniters of this type, then it’s not the controller, it’s the igniter. On the other hand, if your controller can‘t light any igniters of this type, then it’s the controller.

The fact your controller can light some kinds of igniters doesn’t mean it can light all kinds of igniters, even if the igniters are perfectly fine. My first composite motors I flew on my own launch equipment were Aerotech E20s that came with First Fire Jr igniters, and my Estes E controller would not light those. I had to use Estes PSII igniters for those E20s when I used my own controller. But the First Fire Jr igniters that would not work with my equipment were actually perfectly fine, and I used those at club launches on their big 12-volt equipment.

Also, just because you get a continuity light, does not mean the igniter is good. Even if there are no shorts on your leads and setup (clips not touching, etc.) the igniter can have an internal short you cannot always see. If there is a bridge wire or chip covered in pyrogen, you might never see that there is a short between the lead wires underneath the pyrogen. Some kind of manufacturing defect with stray solder or something similar bypasses the bridge wire under the pyrogen, and you never see it. Even though it looks good, and the continuity light comes on, it’s never going to light. Toss it out, and use another.
 
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Sluggo

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Was this the only igniter of its type (brand and model) you used? If your controller can light other igniters of this type, then it’s not the controller, it’s the igniter. On the other hand, if your controller can‘t light any igniters of this type, then it’s the controller.

The fact your controller can light some kinds of igniters doesn’t mean it can light all kinds of igniters, even if the igniters are perfectly fine. My first composite motors I flew on my own launch equipment were Aerotech E20s that came with First Fire Jr igniters, and my Estes E controller would not light those. I had to use Estes PSII igniters for those E20s when I used my own controller. But the First Fire Jr igniters that would not work with my equipment were actually perfectly fine, and I used those at club launches on their big 12-volt equipment.

Also, just because you get a continuity light, does not mean the igniter is good. Even if there are no shorts on your leads and setup (clips not touching, etc.) the igniter can have an internal short you cannot always see. If there is a bridge wire or chip covered in pyrogen, you might never see that there is a short between the lead wires underneath the pyrogen. Some kind of manufacturing defect with stray solder or something similar bypasses the bridge wire under the pyrogen, and you never see it. Even though it looks good, and the continuity light comes on, it’s never going to light. Toss it out, and use another.
Right. All the ignitors are the same. Aerotech E through G's. There's no doubt in my mind that it was a bad ignitor. I had 1 bad ignitor. I replaced it and the rocket went high. They all went high.!! It was a great day to fly.
 

ThirstyBarbarian

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Right. All the ignitors are the same. Aerotech E through G's. There's no doubt in my mind that it was a bad ignitor. I had 1 bad ignitor. I replaced it and the rocket went high. They all went high.!! It was a great day to fly.
That’s great. It sounds like a fun day, and I’m totally envious.

When you mentioned you replaced the motor, and the rocket flew well, I wasn’t sure if you were using another with the same kind of igniter. Usually, I would not swap out the motor for an igniter failure — I just pull the igniter out with the rocket still on the pad and insert a new igniter.

If you are flying on your own, it’s not such a big deal, and you can afford to fiddle around with checking a failed igniter and trying it again, but at club launches, igniter failures are one of the biggest annoyances, and can really disrupt your whole day. Sometimes you can lose almost an hour doing a recycle if the launch is busy enough or has a lot of pads. If one doesn’t go, I replace it, even if it doesn’t look bad. When I go to a club launch, I always have extra igniters of various types in my pockets.
 

Sluggo

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That’s great. It sounds like a fun day, and I’m totally envious.

When you mentioned you replaced the motor, and the rocket flew well, I wasn’t sure if you were using another with the same kind of igniter. Usually, I would not swap out the motor for an igniter failure — I just pull the igniter out with the rocket still on the pad and insert a new igniter.

If you are flying on your own, it’s not such a big deal, and you can afford to fiddle around with checking a failed igniter and trying it again, but at club launches, igniter failures are one of the biggest annoyances, and can really disrupt your whole day. Sometimes you can lose almost an hour doing a recycle if the launch is busy enough or has a lot of pads. If one doesn’t go, I replace it, even if it doesn’t look bad. When I go to a club launch, I always have extra igniters of various types in my pockets.
Looking back on it I should have used the motor. But, I tucked it away and now I have it for the next time I fly. Interesting points on a club launch. I've never done that but I hope to this spring down in Colorado.

Nice reply. Thanks.
 

heada

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Heada...... How many amps does 6 C batteries produce.?? How many amps does an ignitor need to fire.?? And you say "a few amps at 9v." Can you put a number on that the same way you did with a LiPo.??
Under ideal, laboratory conditions, 2A. Under normal conditions, 0.2A to 0.6A. Now also consider the internal resistance of each cell of 0.2 ohms to 0.6 ohms but since you have 6 in series, that adds up to 1.2 ohms to 3.6 ohms. Internal resistance is how much the battery wants to hold on to the power and not release it.

Compare that to the lipo I mentioned which I called out at 4s 50C but didn't list a capacity. So let's make it small at 2000mAh(C cells are normally 6000mAh) That 50C rating is the continuous discharge rate and you multiply it by the capacity so 50C time 2000mAh gives you 100 amps. But let's not stop there. The internal resistance of a lipo is typically 0.002 ohms so add 4 cells and you get a whopping 0.008 ohms or almost non-existent. That's why it's so dangerous to dead short a lipo.

So the 6x C cells can only give an ideal maximum 2A but never actually will because of absolutely horrible internal resistance and crappy chemistry at most 9v so you'll lose tons of power heating the wires but the lipo will deliver 100A at 14.4v (16.8v fully charged) all day, every day. That's why I recommended switching to the lipo.

This is part of rocket science. Get used to dealing with numbers and the like. You've now been ignored. Goodbye.
 

Sluggo

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Glad you got to fly. You know that you ARE making everyone jealous :)
It was a great day, 30 degrees but the rather short walks to retrieve the rockets allowed me to wear just a thermal and heavy sweatshirt and a ballcap. I loved this..... It's soo quiet up there on the field. I think I saw just 1 truck roll by. The silence allowed me to hear the ejection and the chute filling with air. Pretty cool stuff. I love the outdoors. I love this moon shot.
 

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Sluggo

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Under ideal, laboratory conditions, 2A. Under normal conditions, 0.2A to 0.6A. Now also consider the internal resistance of each cell of 0.2 ohms to 0.6 ohms but since you have 6 in series, that adds up to 1.2 ohms to 3.6 ohms. Internal resistance is how much the battery wants to hold on to the power and not release it.

Compare that to the lipo I mentioned which I called out at 4s 50C but didn't list a capacity. So let's make it small at 2000mAh(C cells are normally 6000mAh) That 50C rating is the continuous discharge rate and you multiply it by the capacity so 50C time 2000mAh gives you 100 amps. But let's not stop there. The internal resistance of a lipo is typically 0.002 ohms so add 4 cells and you get a whopping 0.008 ohms or almost non-existent. That's why it's so dangerous to dead short a lipo.

So the 6x C cells can only give an ideal maximum 2A but never actually will because of absolutely horrible internal resistance and crappy chemistry at most 9v so you'll lose tons of power heating the wires but the lipo will deliver 100A at 14.4v (16.8v fully charged) all day, every day. That's why I recommended switching to the lipo.

This is part of rocket science. Get used to dealing with numbers and the like. You've now been ignored. Goodbye.
Oh boo hoo. I am sooo broke up and in tears. Crying. Man, I wouldn't want to be around this guy when real things go bad.
 

BEC

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My first composite motors I flew on my own launch equipment were Aerotech E20s that came with First Fire Jr igniters, and my Estes E controller would not light those. I had to use Estes PSII igniters for those E20s when I used my own controller. But the First Fire Jr igniters that would not work with my equipment were actually perfectly fine, and I used those at club launches on their big 12-volt equipment.
The Estes E controller is an Electron Beam controller with 30 feet of heavier wire than the ”regular” one, but it still just uses 4 AA cells for power. Not surprised you couldn’t get a FirstFire anything (except the new FF Micros that come with Q-Jets) to work on that.

The PSII controller uses six C cells...half again the voltage and quite a bit more current capability.

Also, just because you get a continuity light, does not mean the igniter is good. Even if there are no shorts on your leads and setup (clips not touching, etc.) the igniter can have an internal short you cannot always see. If there is a bridge wire or chip covered in pyrogen, you might never see that there is a short between the lead wires underneath the pyrogen. Some kind of manufacturing defect with stray solder or something similar bypasses the bridge wire under the pyrogen, and you never see it. Even though it looks good, and the continuity light comes on, it’s never going to light. Toss it out, and use another.
This is very true and was suggested by David Schwantz a little higher up in this thread.

Thanks for the confidence in the controller. Like I've said, I like the controller. A lot. We'll see how it holds up.
I have two and one of them is my ”daily flyer” when I am going out to fly outside the club setting. That one has a 3s 1250 mAh Li-poly pack in it and it will light anything I ask it to. I flew all last year and never had to charge the pack.

I bring them both with me when I go to score TARC flights and have lent them to teams who had other setups (such as that Aerotech Interlock) that weren’t working. It is in that context that I’ve had the one with the C cells in it fire a couple of Copperheads over the years, as well as numerous other Aerotech igniters. Of course CTI motors are no problem....but that’s a different discussion.

I’d be a little worried about going 4s as heada suggests not knowing how much voltage the LED and the buzzer can tolerate above the stock 9V of the six C cells. It would have to be a pretty small 4s pack to fit inside anyway....but it might be doable.
 

UhClem

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Ignigters have an all-fire rating (will always ignite)
That isn't quite true. The all fire current is the current where most (99.9%) will fire. Standard practice is to include some margin on either time (all fire current should have a pulse duration as well since it is energy that really matters here) or current.

In addition, the all fire current is an estimate. So even more reason for some extra margin.
 

Sluggo

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BEC .... I agree that a 4s LiPo would be overkill or, kill. That's a big battery. Thanks for your post. I have full confidence in the PSII controller.
 

heada

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That isn't quite true. The all fire current is the current where most (99.9%) will fire. Standard practice is to include some margin on either time (all fire current should have a pulse duration as well since it is energy that really matters here) or current.

In addition, the all fire current is an estimate. So even more reason for some extra margin.
Agreed. I simplified it, just hope I didn't over-simplify it. I've normally seen it as either mA for 1 second or just mA and I assumed the 1 second.
 

Pete.D

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A short circuit inside the igniter would cause this.
Or, a high-resistance connection between the clips and the igniter, due to dirty contacts.

A 12V battery with high capacity could "possibly" overcome either case, but it's not guaranteed to do so; short circuits and dirty contacts are very unpredictable. I used to have a heavy-duty controller with 12 gauge wire that connected to my car battery and the igniter. It was more reliable (overkill, really), but it didn't work 100% of the time, mainly because of dirty contacts at the igniter, and bad igniters. Once I got a short at the igniter and there was so much power available that the insulation on the wire melted.

Your controller is probably fine 90% of the time, as long as the batteries are fresh and the battery contacts are clean. You like it, so definitely keep it. Even the big boys (NASA) don't get everything to work 100% of the time.

If you get a misfire no big deal, it's not like it's a critical air-start. Don't mess around with resistance measurements; they're unreliable too. Just toss the igniter and try another.
 

g.pitts

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This thread has elements of "how to win friends and influence people". Some say that they want to learn, yet they resist the knowledge offered and poke fun at those who try to help. I'm out, too.
 

Sluggo

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A short circuit inside the igniter would cause this.
Or, a high-resistance connection between the clips and the igniter, due to dirty contacts.

A 12V battery with high capacity could "possibly" overcome either case, but it's not guaranteed to do so; short circuits and dirty contacts are very unpredictable. I used to have a heavy-duty controller with 12 gauge wire that connected to my car battery and the igniter. It was more reliable (overkill, really), but it didn't work 100% of the time, mainly because of dirty contacts at the igniter, and bad igniters. Once I got a short at the igniter and there was so much power available that the insulation on the wire melted.

Your controller is probably fine 90% of the time, as long as the batteries are fresh and the battery contacts are clean. You like it, so definitely keep it. Even the big boys (NASA) don't get everything to work 100% of the time.
Great post. Thanks for that.
This thread has elements of "how to win friends and influence people". Some say that they want to learn, yet they resist the knowledge offered and poke fun at those who try to help. I'm out, too.
I don't see it that way. I see it that there are 2 groups of people here. One saying it's the controller and the other saying it's simply a bad ignitor. Because I'm siding with the bad ignitor side and you're not, you've become 'sensitive about it.' When you say "I'm out" I'm jealous. I love the outdoors too.!!
 

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David Schwantz

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I don't think he is saying "I'm out", meaning outside.

I too love being outside. Just got done moving a couple tons of snow again :)
 

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