Estes Sonic Igniter Pro Series II Igniters suck!

[Rex R]

I think that safety of the onlookers is the main concern for installing igniters at the pad, there the rocket is pointed in the right direction .
rex

 

[luke strawwalker]

I think that safety of the onlookers is the main concern for installing igniters at the pad, there the rocket is pointed in the right direction .
rex

LIke it was when the folks on the 4-wheeler got burned by the two stager awhile back??

Just sayin'...

later! OL JR

 

[MarkII]

LIke it was when the folks on the 4-wheeler got burned by the two stager awhile back??

Just sayin'...

later! OL JR

Explain? Which stage lit prematurely (if that's what happened), and why? (I'm not familiar with this incident.) Let me repeat: I have no problem with people following this procedure (waiting until the rocket is loaded onto the pad before installing the igniter in the motor), and as we know, it is required when using high power motors. I am not challenging it at all. I am just trying to understand what the realistic risk is for certain motors. Can a Copperhead, an Estes Solar igniter (i.e., the traditional kind) or a simple loop of nichrome wire "fire" spontaneously in the absence of a launch system? I understand that there are risks involved and precautions that are needed when one is using ultra-low current e-matches; they aren't what I am talking about. Nor am I talking about accidental firings of deployment charges or upper stage motors. Those situations do present fairly obvious increased risks and it is easy to see why they would require extra careful handling.

 

[DAllen]

LIke it was when the folks on the 4-wheeler got burned by the two stager awhile back??

Just sayin'...

later! OL JR

You mean this incident here? Really? So you know exactly what happened there? My understanding is none of the information pertaining to exact cause has been released.

 

[Nerull]

Depends on the motor and igniter. It takes a lot of current to fire a Copperhead; a stray static discharge isn't going to set it off. Same is true for an Estes Solar igniter, a Quest MicroMaxx igniter or one made from a loop of 30ga nichrome. The instructions for small RMS hobbyline reloads call for the igniter to be installed during the motor assembly; you don't want to wait until you are at the pad to put your motor together. I assemble them the evening before the launch. But in the case of ultra-low current e-match igniters, like those used in many CTI reloads, sure. The leads of CTI's igniters are insulated until the time of clip hookup for safety reasons.

Has there ever been an incident of a motor (not a deployment charge, but an actual motor) being spontaneously ignited anywhere away from the pad (and away from any ignition system leads) due solely to the presence of the igniter in the motor? Have there ever been any incidents of igniters spontaneously going off while still in the packaging? (They should be just as likely to be set off when they are outside of a motor as they would be when they are installed in it.)

With all of this being said, though, I don't see anything at all wrong with doing what you describe. In the case of high power motors, it is the required procedure.

I don't know the details, and I wasn't there, but one of the classic stories that gets told about NARAMs is the incident where a K motor lit in the hotel while someone was prepping it.

 

[mwtoelle]

It was an Aerotech I65 single use at a hotel in Danville, IL back in the early 1990s. I have not heard all of the details, but that room required substantial repair work. Fortunately, no one was injured and the only damage was to the hotel room. I don't know what type of igniter was used.

 

[rbeard2]

I'm Baaa-aaack!!!

Well I just got a super nice response from Mike Fritz over at Estes Corp.! I will copy it below so that all can peruse but I do have to say, those guys are the best customer service hounds in the kennel! They are on it as you will see. I will also post my response to Mike's email - sorry for the volume but I think this discussion has legs so here is Mike's response-

HI Ron…I saw your posting on TRF the other day and forwarded to our engine guys (I usually pick up those comments that start with “Estes” and end in the word “suck”). Quite honestly, I’m not sure what the problem is that you experienced. The formula for the tips was developed over time and thousands were tested before these went to market. We’ve produced millions of the Solar Igniters over the years, so it isn’t like we don’t know how to make them and these are basically just longer versions of the Solar Igniters. That’s not to say that we haven’t experienced a no fire condition every once in a while when test flying one of the PSII rockets...but it does happen now and then…mostly because we didn’t insert it all the way or that we didn’t make good contact with the propellant…or once when the AA batteries we so low that it wouldn’t light either. But our experience has been positive…but we need to find out what happened to cause your 0/4 failure rate. I also checked with customer service and the only complaint we’d had so far was for a pack of Sonics that had the ends bent during shipping. We have had good success with these so far, so we’re a little confused about what you experienced.



As for if you’re doing something right or wrong…I can’t say unless we were at the pad together…but it sounds like you’ve been launching a while so it’s not like you’re a newbie. What I would suggest is that if you haven’t done so already, put a slight kink in the end of igniter and make sure that you are getting the igniter all the way in and that good contact is made with the propellant. To help you with this task, let me send you 2 packs of igniters and if all of these fail…well then…I’m not sure what would mean.



I’ve got your shipping info from the email contact so I’ll put an order in for some 2 packs Sonic Igniters and get them shipped to you right away. After you received them and have a chance to use them, please get back to us with your experience and if you go 0/8…well, we’ll have to have another conversation about “how” you use them…but let’s try these replacement igniters first…and just as an FYI…these are production igniters…not hand-picked or “select” igniters…just everyday product igniters that you’ll be receiving so you can have a straight up comparison.



Ron, have a great Memorial Day weekend and we’ll get these shipped early next week and look for a more positive reply from you regarding the Sonic Igniters.

Regards,

Mike Fritz

Estes-Cox Corp.

 

[rbeard2]

and here is my response -

Mike,

I will, regardless of how the new igniters test out, be posting another thread about the superior customer service of Estes inc. My son and I cracked up our Big Daddy last year and instead of selling us a replacement nose cone which was what we asked for, you guys sent us a whole new kit - no cost and no questions asked. I have re-told that story personally and will make sure it gets out there about your response to my current situation as well.

I think the tone of my post may have seemed a bit harsh and if so I apologize. My club - the excellent TORC703 out of Dayton Ohio - had just finished 2 consecutive community outreach/volunteer programs. The first was "Space Days" at the U.S. Airforce museum where we launched over 100 demonstration flights for over 1000 visitors and answered questions, helped the gift shop sell kits, and picked up several new BARs as club members. I had 2 Sonic igniter failures at this event in front of crowds. The second event was the Boy Scouts "Funboree" at Camp Birch in Yellow Springs Ohio. We built, launched and recovered aprox. 480 Gold Chrome Domes and AlphaIIIs all on the old reliable Estes B6-4s. The boys had a great time and again model rocketry was showcased at a demo flight that evening. I personally launched 6 rockets including my personal "and crowd" favorite "The Star Chip Enterprise" made from Pringles potato chip cans but again - 2 more sonic2 failures. We obviously want all of our flights to go off as planned but especially when we're introducing kids to the hobby or trying to get their dads back into it. Spectators will understand of course but when it's your bird on the pad and you've been hyping it all day and the LCO has just finished the count-down over the loud-speaker . . . you get my drift . . so if I sounded a little douchey in my post, that's where it came from.

I love rockets and rocketry and I love the Estes Corp. My Dad bought me my first kit - a Big Bertha - in 1979 and I have logged well over 1000 flights since then. The reliability of the standard Estes black powder engines and igniters is legend. They are literally a perfect product/system. Evidence the recent scouts launch - can you guess how many launch failures out of 480 attempts we had with the B6-4s that were not our fault? - zero. That's amazing and it's what I have come to expect from you folks. I want that legacy of perfection and "the gold standard by which all others are measured" to continue for you guys!

Aerotech, IMHO, is an excellent comapny but I do not hold them up to the same esteem as I do Estes. Their motors, when lit, are fantastic. I use the singles and the reload kits with great success BUT the missing link is that crap copperhead ignitor. I've heard all about not using the toothed clips and some people melt the end with a lighter and separate the leads - ya-da ya-da. I don't think I should even have to think about that when a perfectly reliable component exists already! In my experience, the only igniter I have used that would give that "perfect system" grade to the awesome new mid-power line up from Estes is a "First Fire Jr. igniter" or clone there of. I have had the same 100% no-fail, no-fiddle, simple-to-use and reliable-as-hell experience with those igniters in mid-power engines as I have with their smaller Estes cousins. Why fix it if it's not broke? Even if we were to do a side-by-side comparison test of the SonicIIs vs. FirstFire Jr.s and the FFjrs came out only 5% more reliable - isn't that worth it to remain the worlds undisputed, leader in both quality of design and reliability of product?

I will be glad to test some more of your igniters and will honestly report back to you on how they fare. But I will also stuff an FF Jr. into any motor that the Sonic2s fail to light, just as a control to the experiment!

Thanks for your sincere consideration
A life-long Estes fan-atic (and wordy too!)
Ron Beard

 

[Rex R]

flew my ventris today, on an Estes F50-6(Estes did their homework on motor suggestions), used a sonic igniter too. I did put a slight bend in the wire just below the head (which I note that AT suggests for both the copperhead AND the first fires). used a 12v controller. everything worked like it was supposed to.
rex

 

[Tom Swift]

Flew a Leviathan three times on Saturday. This was my first time using composite motors (F23-4FJ), but I was guided by two folks with plenty of experience. First try, the igniter went in easily and we checked SEVERAL times to be sure it went in ALL THE WAY. The launch controller was a 12 volt system with plenty of juice, but... fizzle. Next try, I bent the ignitor slightly just below the head to help get good contact with the propellant and inserted it all the way, but no luck. Third try, the ends of the bridge wire on the sonic ignitor were too long so the tip would not fit into the motor. I began bending the tips back slightly but the pyrogen started to crumble away. I was able to shove the igniter into the motor only about 1 inch. But this time the motor lit, and the Leviathan had a great maiden voyage.

I prepped her for another launch, the igniter fit perfectly and lit on the first try. Great flight.

For the third launch (second pack of igniters, purchased from a different vendor) I again found that the igniter wouldn't fit into the motor (Estes F26FJ this time). Again some pyrogen started to come off during my efforts to insert it. Ultimately I was able to insert it only about 1/2 inch into the motor. Not recommended, but it was enough to do the job. Another very nice flight and recovery.

 

[Art Upton]

I don't know the details, and I wasn't there, but one of the classic stories that gets told about NARAMs is the incident where a K motor lit in the hotel while someone was prepping it.

Hummm.. I was there and saw the smoke from the motel window, I-65 lit when someone tested the installed ignitor with an ignitor tester, and it was a Tripoli Danville Dare launch not a NARAM.

On the topic at hand, I have tried 4 of the sonics so far on F26-FJ and G40 Estes motors, none ignited so far. I had to use Aero-Tech first-fire Jrs taken out of Aerotech motor packs I had to get the Estes motors to lite. In a few weeks I will try the F50s out with the sonics and see if they work. My note would be if a bend is needed to the propellant, not just the nozzle end, lets put it in the Estes Instructions, not the AT website.

I am glad to see the AT motors sold by Estes at the box stores, and bought and built one of the new kits already. Just hope the ignitor issue can be solved with simple instruction changes as Fred points out.

Art

 

[Zonie]

Sooo, perhaps dipping the sonic's in igniterman pyrogen would help?

FWIW, I have never had a copper head fail. Never in 12 years as a BAR.

Technique and attention to detail are key.

Ensure the tip of the igniter is touching the BOTTOM of the DELAY Grain. You can mark the depth of the wire with a sharpie while building the motor, so when you are at the pad, you know it is all the way in and not stuck partway. Especially helpful in 24mm and 29mm C-slot motors.

Notch the closed edge of the red nozzle cap-plug for venting, and ensure that when you slip the cap on, it doesn't pull the igniter out a bit. I bend the lead over the nozzle manually to prevent this.

Use tape and smooth clips. I make little stickers like on the old Quest tiger tails with masking tape and a single hole puncher I keep in my range box.

The copperhead clip is a waste of time, and melts easily.

 

[JPVegh]

The copperhead clip is a waste of time, and melts easily.

I just gotta speak up for the copper head igniter clip. It has been my experience that the clip works very well in its intended purpose and I have yet to melt one. Clean the contacts after every use and don't forget to pick it up and it will last for many years as mine have. No separating copper foil, no taping, just clip it on and your good. I've never used one on anything bigger than an I motor though so I can't speak to its use on larger motors.

 

[Wayco]

I'm gonna back up Jeff on this topic Chris. I have had great success with this clip also, I modified mine by soldering it to a length of two strand copper wire. It doesn't get lost that way if you tie it off on your launch pad. I clean mine with a piece of emery cloth after each use and it works every time. I used two of them when we launched Sharons Starburst cluster, the only time we had both E18's light.....

 

[rbeard2]

Guess what??

In the last 5 days I have received 2 boxes from Estes containing 2 packs of SonicII igniters for a total of 16 testable subjects! I am inclined to conduct a backyard, side-by-side comparison of the current leaders in Mid-power igniter tech!

The contenders:

- Estes Sonic II
- Aerotech Copperhead
- Aerotech First Fire Jr.
- Quest Q2G2 Long 8s

I think a slew of 24mm Aerotech E20-4Ws will be the standard test engine, yes? "White" propellant is notoriously finicky so it should be the bench mark don't you think?

Please post any suggestions for how to make this a fair/more complete test and I will video/post the whole thing on youtube and here (with perm from the mods)!

We can settle this stinker once and for all!!!
What say you brothers?!?

 

[jpummil]

So...Estes sent you a couple of boxes free of charge? If so....:clap: Estes!!!

Yes, I would be interested in seeing that data. Hope the original igniters were just a fluke. Not a Copperhead fan, but have always had great success with First Fire JR and Q2G2. Would be grand if Estes is comparable!

 

[Rex R]

wrap mega mosquito or a super neon xl around those motors .
rex

 

[Shamous]

Guess what??

In the last 5 days I have received 2 boxes from Estes containing 2 packs of SonicII igniters for a total of 16 testable subjects! I am inclined to conduct a backyard, side-by-side comparison of the current leaders in Mid-power igniter tech!

The contenders:

- Estes Sonic II
- Aerotech Copperhead
- Aerotech First Fire Jr.
- Quest Q2G2 Long 8s

I think a slew of 24mm Aerotech E20-4Ws will be the standard test engine, yes? "White" propellant is notoriously finicky so it should be the bench mark don't you think?

Please post any suggestions for how to make this a fair/more complete test and I will video/post the whole thing on youtube and here (with perm from the mods)!

We can settle this stinker once and for all!!!
What say you brothers?!?

Sounds great. I suggest using both 6 and 12 volt systems because Estes recommends using the blue E launch controller. Also compare straight verses bent tips.

 

[accooper]

Even with my home made igniters I give the head a very slight bend. But here is something else to consider:

1. To ignite a composite motor you need a VERY strong 12volts and as many amps as possible.

2. A great launch controller.

3. Absolutely clean igniter clips.

I have seen guys make there own igniters with twice or three times the necessary magnesium hoping that their marginal battery will ignite the motor.

Andrew

 

[jadebox]

Sooo, perhaps dipping the sonic's in igniterman pyrogen would help?

FWIW, I have never had a copper head fail. Never in 12 years as a BAR.

Technique and attention to detail are key.

Ensure the tip of the igniter is touching the BOTTOM of the DELAY Grain.

Some motors have a gap between the bottom of the delay and the top of the propellant. So, the tip of the igniter should touch the propellant near the top of the propellant, not the bottom of the delay. Otherwise you run the risk of igniting the delay without igniting the propellant. That happened to me once.

-- Roger

 

[jadebox]

The comments from Estes mentioning their experience with Solar Ignitiers and their recommendation of using the Estes E Launch Controller makes me wonder if the Sonic Igniters work better with lower voltage/current launch controllers. Maybe the 12V systems we tend to use for larger rockets are causing the igniters to burn too quickly and that's causing some of the reported problems.

-- Roger

 

[shreadvector]

NO.

The compostie motor does not see the current supplied to the igniter. It sees the heat created by a properly ignited igniter.

Different igniters need different current. Copperheads need lots of current. Estes Solar or sonic igniters do not need a huge amount of current and should not fail if extra current is supplied.

IF the igniter bridge wire is blown to bits without properly igniting the pyrogen on the tip, the pyrogen will not completely burn and the propellant will not get the heat it needs to ignite. I have seen this on the Aerotech igniters supplied with ValueRockets motors in past years - the ones that look like Q2G2 igniters, but are allegedly different. Top was popped off igniter but rest of pyrogen remained unburned.

I have not really noticed a problem with BP motors using Q2G2 igniters, but if the top is blown off the igniter by using a car battery for power, it is blown directly against the propellant face inside the BP motor, so as long as the straw is holding it in place, it will ignite the motor.

For composite propellant, you want a hot flame that starts at the top and extends down a bit and keeps burning for a while. Perhaps the Sonic igniters need a second dip or a slightly heavier single dip? They will still fit through the nozzle throat and core, but they will then burn longer and hotter.

Even with my home made igniters I give the head a very slight bend. But here is something else to consider:

1. To ignite a composite motor you need a VERY strong 12volts and as many amps as possible.

2. A great launch controller.

3. Absolutely clean igniter clips.

I have seen guys make there own igniters with twice or three times the necessary magnesium hoping that their marginal battery will ignite the motor.

Andrew

 

[jadebox]

NO.

There's no need to shout.

Estes Solar or sonic igniters do not need a huge amount of current and should not fail if extra current is supplied.

I suspect that it's possible for the additional current to cause the igniter to not properly ignite. Sort of like...

IF the igniter bridge wire is blown to bits without properly igniting the pyrogen on the tip, the pyrogen will not completely burn and the propellant will not get the heat it needs to ignite.

The bridge wire must also be hot long enough for the heat to ignite the pyrogen. If it heats up and breaks, opening the circuit too soon, there may not be enough time for the pyrogen to ignite.

BUT ... I've seen a lot of rockets using Solar igniters launched using relay systems with large batteries near the pads. I don't think I've seen any fail because of the more powerful controllers. So, there's no evidence that it could be the problem with the Sonic igniters (if there really is a general problem with them).

-- Roger

 

[rbeard2]

So OK, I think we will go with a 12Volt system as this is the standard club launch voltage in the US and I happen to have a fresh 12V truck battery I can use in the backyard test.

I will be buliding a simple test rig and testing all of the igniters out on Aerotech E20-7Ws as I can get them for about $7.00 each - UNLESS SOME REALLY COOL TRF SURFER WHO HAPPENS TO BE EMPLOYED BY EITHER ESTES OR AEROTECH WANTS TO DONATE A COUPLE DOZEN MOTORS TO THIS CONSUMER-DRIVEN AND HIGHLY ANTICIPATED/PUBLICIZED TEST?? HMMMMM???

Dream a little dream I say . . .

 

[shreadvector]

Bridge wire in Solar and Sonic igniters will not melt or 'pop' without heating the pyrogen if you apply higher voltage or massive power.

It is a combination of the bridge wire and the pyrogen. Some bridge wires are really, really teeny and will melt with little heat generated if they are overpowered. And some pyrogens take abit more heat to get them burning.

There's no need to shout.



I suspect that it's possible for the additional current to cause the igniter to not properly ignite. Sort of like...



The bridge wire must also be hot long enough for the heat to ignite the pyrogen. If it heats up and breaks, opening the circuit too soon, there may not be enough time for the pyrogen to ignite.

BUT ... I've seen a lot of rockets using Solar igniters launched using relay systems with large batteries near the pads. I don't think I've seen any fail because of the more powerful controllers. So, there's no evidence that it could be the problem with the Sonic igniters (if there really is a general problem with them).

-- Roger

 

[be69ar]

So OK, I think we will go with a 12Volt system as this is the standard club launch voltage in the US and I happen to have a fresh 12V truck battery I can use in the backyard test.

I will be buliding a simple test rig and testing all of the igniters out on Aerotech E20-7Ws as I can get them for about $7.00 each - UNLESS SOME REALLY COOL TRF SURFER WHO HAPPENS TO BE EMPLOYED BY EITHER ESTES OR AEROTECH WANTS TO DONATE A COUPLE DOZEN MOTORS TO THIS CONSUMER-DRIVEN AND HIGHLY ANTICIPATED/PUBLICIZED TEST?? HMMMMM???

Dream a little dream I say . . .

...don't push it...Mike

 

[luke strawwalker]

The comments from Estes mentioning their experience with Solar Ignitiers and their recommendation of using the Estes E Launch Controller makes me wonder if the Sonic Igniters work better with lower voltage/current launch controllers. Maybe the 12V systems we tend to use for larger rockets are causing the igniters to burn too quickly and that's causing some of the reported problems.

-- Roger

This is a misconception... the ignitor will ONLY use as much power as it needs to heat up and melt the bridge wire (fire)... NO MORE... it will ONLY use this much power REGARDLESS of how much power is available...

Think of it like a fire hydrant attached to a water main on an 8 inch riser off a 12 inch water main... The hydrant is capable of delivering a HUGE volume of water (amperage) at standard pressure (40-60 PSI) (voltage). Now, with the appropriate adapters, you COULD connect up a GARDEN HOSE to this hydrant and water your flowers without blowing them out of the ground OR flooding the yard in 2 minutes flat... because the garden hose will ONLY allow the "usual" amount of water to pass through it, REGARDLESS of how much capacity the hydrant is CAPABLE of delivering... make sense?? Therefore, a "low current" ignitor is just as capable of being fired by a "high current delivery" (fire hydrant) style launch controller as a "high current" HPR ignitor is... The HPR ignitor will use the additional current delivery (say by connecting a fire hose to the hydrant instead of a garden hose, in water terms) that the hydrant is capable of delivering...

Now, say we have the opposite situation... we connect up a fire pumper truck to a garden hose coming from the neighbor's 3/4 inch hose spigot on the side of the house... the fire hose is only going to dribble, no matter how hard and fast the pumper truck runs, because the 3/4 inch garden hose simply CANNOT deliver the amount (volume) of water needed to supply it... (IOW, insufficient "amperage" is available). This is the same as trying to ignite a high-current ignitor with a low-current system that's incapable of delivering enough current to heat up the ignitor and fire it.

Then there's voltage. Say we hook the fire pumper truck up to the hydrant, and then use a 3/4 inch garden hose to deliver the water... we crank the truck up to full power, kicking the pressure up from say the water main pressure of 50 PSI to 150 PSI at high volume... can we deliver enough water to put out the house fire?? No, because the 3/4 inch garden hose is incapable of delivering that much volume (amperage). A LOT more water will flow from the garden hose, but the tiny hose is going to produce a huge amount of resistance to the flow, pressure will build, and the hose will rupture and blow out... Similarly, we can deliver a LOT more power (wattage, ie HEAT) to the ignitor by upping the voltage (pressure) but at some point, the ignitor will be overwhelmed... for instance, trying to use 110 volt power to fire the ignitor will likely simply snap the bridge wire before it ever heats up enough to ignite the pyrogen... which is why we don't use such high voltages! Just like the garden hose trying to deliver water at such high pressure, it will rupture before doing the job...

Various ignitors (and combinations thereof in the case of clusters) need various amounts of power (wattage) to fire, depending on the ignitor type and its construction... some are "low current" and some are "high current". Now, WATTS=VOLTS*AMPS, so we see that if we double the voltage, we halve the amperage needed to flow through the ignitor to deliver the same wattage to the bridge wire. If we HALVE the voltage, we DOUBLE the amps needed to deliver the same wattage. A wire doesn't particularly care how much voltage it carries (within reason-- eventually at high voltages the insulation capabilities break down and the wire arcs) but resistance (ohms) increases proportionally with amperage passing through the wire... IOW, the more current we pass through the wire, the more resistance that current experiences... like trying to force too much water through a garden hose at high pressure... in fact, in hydraulics, you have to QUADRUPLE the pressure to double the flow rate delivered through a given hose (orifice) size-- it works similarly for electricity IIRC).

So, what does all this mean??

1) we want the highest reasonable voltage we can get to deliver the maximum wattage a particular launch system is capable of delivering... that's why 6 volt launch controllers are particularly bad at delivering enough current for multiple ignitors... the voltage (pressure) is simply too low to force much current (flow) throught the wires (hose). We just don't want to OVERPRESSURIZE they system or ignitor(s) with TOO MUCH voltage... IOW for our applications, 12 volts is sufficient for most applications-- maybe 18-24 at the VERY MOST for LONG runs of wire-- remember the wires are for all intents and purposes insensitive to increasing voltage, which helps overcome resistance and delivered wattage... so long as we don't burn out the ignitor before it can heat up enough to fire (burst the hose).

2) the ignitor(s) will only use as much power as they NEED, NOT the maximum we can deliver... it's perfectly fine to hook up an ignitor needing 2 amps to a controller capable of delivering 20 amps... only 2 amps will flow through the system before the ignitor fires... it's equally fine to hook up an ignitor needing only 100 milliamps to the same 20 amp capable system-- only 100 milliamps will flow before the ignitor fires... BUT,

3) our controller MUST be capable of delivering the wattage necessary for the ignitor(s) to fire... If we have a 6 volt system (low pressure) with small wires (garden hose) we're not going to be able to deliver enough water (wattage) to put out the house fire... We need sufficiently large voltage (pressure) with sufficiently large conductors (hoses) to deliver the required wattage (volume) to do the job. This compounds with clusters where the wattages of all ignitors add up, as does the current requirements at a given voltage (remember-- doubling voltage doubles wattage delivered at the same amperage, and increasing the amperage required by adding more ignitors increases resistance in the wires proportionally).

4) larger wires produce less resistance than smaller wires... thus increasing the wattage they're capable of delivering at a given voltage. (same as a large fire hose can carry more water than a small garden hose at the same pressure). So we want to use the biggest wires we reasonably can for our launch controllers... lamp cord or extension cord is ideal and cheap, and MUCH more suitable than dinky double-lead bell wire and such...

5) I haven't discussed power sources much, but it bears mentioning... say we have a large fire that needs putting out. If we have to haul water from a tanker truck, the pumper will soon run out and putting the fire out will be very difficult, compared to the pumper being able to draw upon a "limitless" supply from a fire hydrant... the truck simply cannot carry enough water! It's quite similar with power sources for our launch controllers... battery choice will determine whether we have a "tanker" or a "fire hydrant". Low resistance, high capacity batteries like lead acid batteries, gel cells, and such can deliver almost "limitless" power to our controllers. High-resistance, low capacity batteries like dry cells, on the other hand, are very much the highly-limited "tanker trucks" of the battery world... and are thus SOON DRAINED of their capability of delivering the power (water) we need... You can put a stack of "AA" batteries together to make 12 volts, but you can't start your car with them-- they won't deliver the 100 amps or so necessary to spin the starter... they simply don't have the capacity to do it! Much like the fire hydrant drawing through a large pipe directly off the water main, even a small lead-acid or gel-cell battery can deliver massive amounts of current (when required) at the designed voltage (pressure) for a long period of time as needed... and of course, the larger the battery, the more "capacity" it has... like the difference in the amount of water in a puddle compared to a lake...

Hope this clears up a few of the misconceptions...

later! OL JR

 

[jadebox]

Thanks. I often use the water hose analogy when thinking about electrical flow. It helps to explain just about everything except why the electrons don't pour out of the unused electric socket.

Similarly, we can deliver a LOT more power (wattage, ie HEAT) to the ignitor by upping the voltage (pressure) but at some point, the ignitor will be overwhelmed... for instance, trying to use 110 volt power to fire the ignitor will likely simply snap the bridge wire before it ever heats up enough to ignite the pyrogen...

That's the situation I was hypothesizing. But, as I said, if it doesn't happen with Solar igniters when using a 12V system, it's probably not going to be a problem with the new igniters.

At this point, I'm not convinced that the "problem" isn't just anectdotal. So, coming up with a theory to explain the problem was a bit premature anyway.

-- Roger

 

[luke strawwalker]

Thanks. I often use the water hose analogy when thinking about electrical flow. It helps to explain just about everything except why the electrons don't pour out of the unused electric socket.



That's the situation I was hypothesizing. But, as I said, if it doesn't happen with Solar igniters when using a 12V system, it's probably not going to be a problem with the new igniters.

At this point, I'm not convinced that the "problem" isn't just anectdotal. So, coming up with a theory to explain the problem was a bit premature anyway.

-- Roger

Thanks... I was just throwing that out there by way of explanation so that maybe it would make it clearer for folks that might be following the discussion... I've seen a lot of posts over the past few months about modifying controllers or building homemade ones that are starting to take voltage to an extreme... folks need to know WHY certain voltages work better and the effects of voltage on the system operation... "more" isn't necessarily "better"... up to a certain point, SURE, but there IS a point of diminishing returns, or even turning things negative... IMHO unless you're running 100 feet of wire out to the pad, 12 volts is fine for every use under the sun... and if you REALLY need tons of current delivered with minimum resistance, a relay controller is the way to go anyway, so the run length is a moot point anyway since the battery is at the pad with short, heavy guage wiring to the relay and ignitor for maximum current delivery... the leads need only carry enough power to activate the pull-in solenoid on the relay. 18 volts is pretty readily available in power tool batteries, and I suppose if one so desired they could go up to a 24 volt system if they were just wanting to do that for some reason... maybe using small lawnmower batteries or something with long run leads to the pad... I think it's pretty pointless IMHO going with voltages higher than 12 volts in 98% of the cases out there...

The sensitivity of an ignitor bridgewire (or conductive pyrogen) to "snapping" from excess voltage driving too much current through it too quickly and "snapping" the bridgewire or pyrogen before it actually absorbs enough heat wattage to actually reach the ignition temperature would be an interesting research project, I think... Of course this "value" would fall into a "range" since minor differences in the construction of individual ignitors would doubtlessly affect the results...

Later! OL JR

 

[Marc_G]

I've observed that the pyrogen on Solar igniters isn't self-sustaining burn-wise. When I built a 12V ignition and tested it, my first test was botched by the fuse in the lighter adaptor I was using to connect to the 12V jump pack that was my power source. Video of this is over in the Electronics forum somewhere.

So, I hit the launch button, and the ignitors (I had 4 testing cluster ignition simulation) fired briefly. AFter I replaced the fuse that burned out almost instantly, I hit the button again and the ignitors re-lit and burned the rest of their pyrogen.

With this 12V system, I have also recovered Quest Q2G2 ignitors that were less than half burnt. My theory is their wire ignited enough pyrogen to ignite the black powder motor, then they got blasted out the nozzel and extinguished. I saved one and tested it at home. The bridge wire was broken, and the pyrogen (about half of it) was still intact and flamed nicely when I held a lighter to it.

So, the idea that excess power to an ignitor could make the bridge wire break and result in less than optimal pyrogen burn is well within my idea of possible effects. To be clear, though, I've never observed a motor ignition failure due to it.

MArc