Copperhead Ignitors.

[1974_Trident]

Greetings all:

In preparation for my first mid-power launch this weekend I assembled my first reloadable Aerotech motor, a G64-4W. I have read on these forums no end of horror stories about motor failures and quite honestly I would not have bought a single Aerotech motor product had I read those threads before I made the purchase. To play it safe and test my motor assembly skills I tried a static motor test. Nothing happened. The ignitor did not even ignite. I tried a hot automotive 12v battery and still nothing. I took the whole motor inside and removed the ignitor. It looked good as new. I tested the ignitor with an Ohm meter; dead short. I read that copperhead ignitors are prone to short circuiting along the edges where the two layers of copper can get mashed together during manufacture. I took a close look at the edge with a magnifying glass and I swear the ignitor is just a single copper strip. I scraped the edge a bit with a razor and still, all I see is a nice shiny copper edge. I split the tip of the ignitor (non igniting end) with a razor and there certainly is a plastic film between the two layers of copper but it looks like the two layers of copper are fused together quite well along the entire length of the ignitor on both edges. I can scrape more but I am beating the daylights out of this ignitor already and all the scraping in the world will be of no benefit if the shorting extends into the pyrogen.

How often does anybody else here encounter such a badly defective ignitor?

Is something to expect in Aerotech products?

Can anybody here recommend a tried and true method for saving such a badly shorted ignitor without destroying the it?

For other reasons I am exploring other manufacturers of reloads and casings, I don't think I should be limiting my self to 120NS total impulse when I can fly up to 160NS and still remain in the mid-power domain. What other brands are out there which have tried and true components in the mid-power range?

I am reluctant to start digging in to my collection of reload kits to find good ignitors because I do not want a bunch of opened reloads exposed to any humidity if I can avoid it.

 

[UhClem]

Copperheads will read as a dead short on most Ohm meters simply because they are not designed to measure such a low resistance.

With a good meter that has resolution into the milliohms, it is easy to find shorted Copperheads. If the resistance decreases as the measurement point moves away from the pyrogen head, then there is a short.

I built a meter (2 Ohms full scale, milliohm resolution) so I could do this test and I rarely see shorted Copperheads. On the rare occasion that I do have one that is shorted, running it through the wringer (pinch between thumbnail and finger) usually fixes them. In the extreme you can delaminate the igniter leads by the careful application of heat.

 

[1974_Trident]

Thank you, UhClem. How much resistance should a healthy Copperhead read? My ohmmeter only shows tenths of an Ohm.

 

[Initiator001]

I have been buying/flying AeroTech motors since 1985 and I have had very few problems with their product.

I have flown motors from 18mm RMS B6s to 98mm SU K215. During that time I have had two motor failures, both early production F20W Econojets which had been made with too thin forward bulkheads.

My success rate with Copperhead igniters is 95%+ which is the same as my luck with Estes igniters.

I think you will be fine with the AeroTech motors and igniters.

 

[1974_Trident]

Ok, I've done a little more scraping and now the suspect ignitor reads 0.1 Ohms. Although considering the resolution of my Ohm Meter this may have been the resistance all along. I thought about the ignitor and what I would expect from a "Hot" car battery. If the car battery in question is as fully charged as I am expecting I would expect it to completely melt the ignitor lead between the two micro clips if they are as dead shorted as I suspected. Maybe my battery is not as charged as I expect it is. Maybe my eyesight is not what it used to be.

 

[GregGleason]

A commonly known "trick" with the Copperheads is to take the non-pyrogen end of the igniter and expose it to open flame (like a BIC lighter). The thin strips will separate, making it somewhat easier to attach the clips.

I will say that it is my practice to use Quickburst igniters. I bit the bullet and got the igniter kit so I could make my own, and they work. Plus, David Bachelder (aka, Mr. QuickBurst) has provided me with good customer service.

Greg

 

[UhClem]

I just measured a random Copperhead to be sure. It was 0.90 Ohms at the end and 0.79 near the pyrogen head. Which is pretty typical but they do vary as they come in several sizes.

The other end of the question is the current source. Can it provide the required current? The battery is probably OK but what about the rest of it? I like to test using a 1 Ohm 25 Watt power resistor. Attach the resistor to the clips and then apply power while measuring the voltage across the resistor. The goal with a 12V system is greater than 10V. If you can't get that then you need to start checking the various parts for excessive voltage drop.

(10 Amps into a 1 Ohm 25 Watt resistor is a factor of four overload. The RH25 series is rated for short term overloads so if you keep the duration to a few seconds at a time it will be fine.)

 

[terryg]

I do not like copperheads and make my own igniters for the most part. When I run out and have to use the copperheads, I have had the best results by separating the two layers so you can use the clips in a standard manner. This gets rid of the problem of possible shorts and gives better contact to the clips. One of the advantages of flying with a club is that you can borrow an Igniter from someone to help a stubborn motor to ignite. With the low costs of G reloads (currently $9.28 at hobbylinc), they are the most bang for the buck that you can get, even with the sometimes stubborn copperheads.

 

[hardinlw]

My success rate with copperheads approaches 100% when using the special Aerotech clip. When using standard alligator clips, you have to do the tape thing and there are several sources of problems inherent in that. 1) strong alligator clips with teeth will puncture the tape and short out. 2) If the clips hanging off the igniter twist it, you can induce a failure in a previously good igniter. 3) Often there is not much igniter left hanging out of the engine forcing you to put the clips close together and they can touch and short out.

If you had a short in your igniter and hooked it up correctly to a strong power source, it should have burned the copper on one or both sides between the clip location and the short. I've seen people who were not familiar with the copperhead just clip both leads to the igniter without the insulating tape strips. This always leads to burning through the copper between the clips. The fact you did not get burn-through suggests that one of the three criteria I mentioned (shorted igniter, correct hookup, strong source) was not met.

 

[bobkrech]

Trident

I have had only one copperhead failure and that was due to a bend igniter that broke the copper and created an open circuit.

Most first timers fail to get a copper head to work because they shorted out the igniter with their microclips. Were you using AT clips or standard microclips?

If you were using standard microclips, you need to use an insulator or you will short the igniter with your clips.

There are two easy ways to do this.

Easiest way: Use masking tape and cover one side of each clip. Attach the clips so that one clip has masking tape on one side of the igniter, and the other has it on the opposite side, Now the clips will not short the igniter.

Quickest way.

1. Cut a piece of paper 1" long by 1/2" wide.

2.) Poke a small hole in the center about 1/8" in diameter in the center.

3.) Slide the paper over the copper head lead.

4.) Attach one microclip to the copper head on one side of the hole and repeat with the other on the other side of the hole.

5.) Now each clip only contacts one different side to the copperhead and the igniter is not shorted.

Bob

 

[1974_Trident]

Thank you, everybody for your advice. After I logged out last night I completely separated the two copper leads by heating the entire length with a lighter and burning away the Mylar strip in between. That igniter now reads 0.8 Ohms. By the way, I took another look with a magnifying glass and as best as I could tell, the two copper layers were fused along the entire length on both edges.

I am using smooth jaw Microclips, I insulated alternate jaws with electrical tape. Also bear in mind, I detected a dead shorted igniter when I used an Ohm Meter without any clips.

So far I have been given a boatload of great advice on working around numerous known "quirks" unique to the Copperhead igniter:

Scrape the edges of the lead,
Use extreme care to avoid twisting and other strains on the lead,
Use a 24v starting system to burn away any small shorts,
Separate the leads to some degree,
Etc.,

This alone speaks volumes about the reliability of the Copperhead in its factory produced form. At what point am I putting less time into making my own igniters from scratch? I think a bunch of First Fire Jrs. are on my shopping list for my next rocket order. In the mean time I am going to test and prep any igniters I plan on using this weekend.

 

[sam_midkiff]

Thank you, everybody for your advice. After I logged out last night I completely separated the two copper leads by heating the entire length with a lighter and burning away the Mylar strip in between. That igniter now reads 0.8 Ohms. By the way, I took another look with a magnifying glass and as best as I could tell, the two copper layers were fused along the entire length on both edges.

I am using smooth jaw Microclips, I insulated alternate jaws with electrical tape. Also bear in mind, I detected a dead shorted igniter when I used an Ohm Meter without any clips.

So far I have been given a boatload of great advice on working around numerous known "quirks" unique to the Copperhead igniter:

Scrape the edges of the lead,
Use extreme care to avoid twisting and other strains on the lead,
Use a 24v starting system to burn away any small shorts,
Separate the leads to some degree,
Etc.,

This alone speaks volumes about the reliability of the Copperhead in its factory produced form. At what point am I putting less time into making my own igniters from scratch? I think a bunch of First Fire Jrs. are on my shopping list for my next rocket order. In the mean time I am going to test and prep any igniters I plan on using this weekend.

I have always used copperheads on motors they come with. 30 seconds to locate a lighter, 5 seconds to heat the non-pyrogen end with a lighter, and then do what you would do with any lighter. I don't abuse it, but I don't treat it with undue care either. I also find myself fiddling with Estes igniters (they can short if they get loose from the cardboard insulator), and in my youth used straight nichrome looped over a ballpoint and held in by little wads of tissue.

The first time I used a copperhead I worried, and the first time I used an Estes igniter I worried. It's part of doing something for the first time when you want it to work. The best thing to do is to not worry too much, follow the advise, and launch.

Sam

 

[troj]

FWIW, while I'm not a fan of Copperheads (I don't like having to insulate the jaws; I find it an annoyance) for some motors, it's hard to find anything else that fits.

Granted, I've not used anywhere near the number of Copperheads that I have other types of igniters, but when I've used them, the reliability has proven to be *at least* as good as that of other igniter types.

...and I've never had a Copperhead weld the relays on a launch controller at a major launch. Can't same the same for other igniters -- LDRS 25, Terry McCreary and I had the distinct pleasure of launching a rocket as soon as we armed a bank, because the previous launch had welded the relays. It was not a pleasant experience.

-Kevin

 

[JAL3]

A commonly known "trick" with the Copperheads is to take the non-pyrogen end of the igniter and expose it to open flame (like a BIC lighter). The thin strips will separate, making it somewhat easier to attach the clips.

I will say that it is my practice to use Quickburst igniters. I bit the bullet and got the igniter kit so I could make my own, and they work. Plus, David Bachelder (aka, Mr. QuickBurst) has provided me with good customer service.

Greg

Ditto and Amen

 

[1974_Trident]

So, After logging off last night I tested four more igniters from my collection of reloads. All four tested between 0.5 and 0.9 Ohms right out of the bag. I am hoping that the first igniter I experienced difficulty with is my 5% failure. I also tested the battery I thought was good and even at full charge it is only giving me 10.2v, must have a shorted cell. Off to the Diehard aisle this afternoon. If this pneumonia lets up a bit I may go outside and reattempt a static test of my first ever reload.

 

[MarkII]

My only experience with using a Copperhead (on my own) was this past summer at NARAM. I had a devil of a time getting the darned thing into the opening of the slot in the G40 - it was like pushing a wet noodle uphill, and it got a bit kinked up in the course of about a dozen attempts to insert it. Finally I used a thin stick to poke the head through the opening and into the slot; after that I was able to gradually work the igniter all the way in until the head was at the top of the grain. The leads on the mid-power pads had smooth-jawed clips, and I did the masking tape on one jaw of each clip thing. No ignition after three launch attempts. I really wanted to get it to work, too, but finally I went back to the Aerotech tent and bought a pack of First Fire Jrs. The motor lit promptly on the very next attempt. I still have the Copperhead and I am at a loss as to why it didn't work. The pyrogen is still all there on the head, so it obviously didn't fire. I don't know; are the metal leads so delicate that I could have broke one when I pushed the head into the slot with the stick? I used care when I did that and didn't just jam it in because I didn't want to damage the igniter. Obviously I can't draw any conclusions from a single experience and I do want to be able to use the Copperheads that come with the motors, rather than having to buy extras.

MarkII

 

[rocket999]

Don't waste a good motor by test firing it. The motor is reliable, and if your only worry is the ignitor than just buy some first fires or make your own. When I use copperheads i get about an 80% success rate. The worst you will be risking is is a trip out to the pad.

The motor will last if you can't get it off at one launch. Just loosen the aft closure and stick it into a ziploc bag. It will be good as new for a long time (I have used them like this after 3 months, and friends have stored them up to 8 months).

Let us know how the flight goes.

Sam

 

[MarkII]

My only issue with FF Jr.'s is that they are not bundled with the motors or reloads, and therefore represent an additional expense that adds to the cost of the flight. Not everyone wants to have to source all of the the materials and then set aside some of their hobby time in order to make their own igniters, although that seems like a good option if one can do it. If a motor or a reload kit includes an igniter, though, I prefer to use it if I can. After all, I'm paying for it when I buy the motor or kit. At NARAM I paid something like $11-12 for a pack of three First Fire Jr.'s. The one that I ended up using added $4 to the cost of the flight on top of the roughly $25 that I spent for the G40. I'm still kicking myself for not being able to get the Copperhead igniter that came with the motor to fire, but the problem was probably due as much to my inexperience with using them as anything else.

MarkII

 

[Handeman]

I agree about using the igniter you pay for with the reload. It seems that some reloads are not or might not be coming with igniters anymore. (BATFE again). That is why I started making my own. I make and mix my own pyrogen and collect the used wires at the launch. I estimate my igniters run about $0.02 each and different sizes have been used in F - M motors.

 

[MarkII]

I agree about using the igniter you pay for with the reload. It seems that some reloads are not or might not be coming with igniters anymore. (BATFE again). That is why I started making my own. I make and mix my own pyrogen and collect the used wires at the launch. I estimate my igniters run about $0.02 each and different sizes have been used in F - M motors.

I should probably look into doing that for myself. Who do you get your pyrogen mix from?

MarkII

 

[Handeman]

I should probably look into doing that for myself. Who do you get your pyrogen mix from?

MarkII

Mine comes from the drug store, the hardware store, the sporting goods/camping store.

PM me and I'll send the recipe along. Don't want to upset the mods.

 

[GaEx]

my experience with copperheads has always been positive once I learned the basics to use them. Sadly its not as easy as attaching clips and launching most of the time. The tape around half of both the clips has always worked perfectly for me. Make sure there's a part of the tap on both sides of the ignitor, im not at home so I can't take a picture and show you, but to explain it with tape on half of each clip, you have tape facing you and tape away from you. Never really had any issues. I'll try to get a picture tonight. Or do what the others have said, make your own. certain online manufactures sell kits.

 

[Pat_B]

For me, once I started reading information about how to test CH's as well as the many different ways to modify them in order to get them to work, that's when I realized that the product wasn't worth the hassle.

CH's should NOT require testing unless AT fails to manufacture them properly, nor should they require modification of any sort. I've always wondered why the edges weren't scraped during the manufacturing process so that the ignitor is delivered to the end user ready-to-go. The fact that so many people have created 'work arounds' for this simple product is evidence of poor design and manufacturing.

 

[mIcahel]

Copperheads work great and are priced competitively at FREE! Just use
the AT clip, don't even bother with any scraping you're fine. Easier than estes and no insulation to remove. Once you start getting your crummy fingerprints and bending them around them with testing, etc. you're only causing problems. Buy some FF Jrs or Quest for club launches.

 

[Handeman]

For me, once I started reading information about how to test CH's as well as the many different ways to modify them in order to get them to work, that's when I realized that the product wasn't worth the hassle.

CH's should NOT require testing unless AT fails to manufacture them properly, nor should they require modification of any sort. I've always wondered why the edges weren't scraped during the manufacturing process so that the ignitor is delivered to the end user ready-to-go. The fact that so many people have created 'work arounds' for this simple product is evidence of poor design and manufacturing.

I don't test copperheads, I don't modifiy them, and I don't scrape the edges. I bought a 10 pack of FFs in 2004 when I had a copperhead fail to ignite a motor. I gave away 3 or 4 from the 10 pack and finally used the last one in 2009. That's 6 or 7 failed copperheads in 6 years. I usually see that many failures of non-copperhead igniters in one days launch. I'm very happy with copperheads and will continue to use them.

 

[SCE to AUX]

I get around the connection problem with copperheads by tack soldering short lengths of insulated hookup wire to the 2 sides of the copper ribbon. nearly 100% success in getting them to fire with this technique. Somewhat less success in actually getting the igniter to actually light the propellant. There seems to be a wide variation in the amount of pyrogen coating on copperheads, and the lightly dipped ones don't work as reliably.

 

[Mikus]

There seems to be a wide variation in the amount of pyrogen coating on copperheads, and the lightly dipped ones don't work as reliably.

Boy howdy! Last weekend I ran across a copperhead from a 29mm kit that had the biggest blob of pyrogen I have ever seen on ANY copperhead. It looked like a giant sper... well, you get the picture. :confused2:

I couldn't get it through the nozzle, so I tried to disassemble the aft end to thread it up the c-slot and back through the nozzle. But the head was so big it wouldn't fit through the c-slot either. I ended up using another copperhead for that motor and building the next motor around that bad boy.

And did it light? Click, boom, gone.

 

[MarkII]

How common is the problem that I had, where you have difficulty getting the pyrogen head into the slot and then pushing it all the way up to the top of the motor without getting the igniter crimped and folding it up on itself? I have only used one, but I have watched others struggle to install them. It looked like they were trying to push a strand of cooked spaghetti uphill. (This was with single use motors, so there was no option to dismantle and reassemble the motor around the igniter.)

MarkII

 

[MattieShoes]

I've used exactly one copperhead ignitor (on a single use G38FJ) and I had the issue where the igniter won't fit in the motor due to the shape of the pyrogen at the tip. I just traded it out with another igniter that goes to a reload kit, since you can slip those in from the side during assembly.

Success rate so far, 100%, and using only FJ motors no less ;-)

 

[cjl]

I've used exactly one copperhead ignitor (on a single use G38FJ) and I had the issue where the igniter won't fit in the motor due to the shape of the pyrogen at the tip. I just traded it out with another igniter that goes to a reload kit, since you can slip those in from the side during assembly.

Success rate so far, 100%, and using only FJ motors no less ;-)

FJ propellant is much, much easier to light than J though. I've noticed that fast blackjack motors light right up, with almost zero hesitation, while blackjack motors can sit there for a while and think about it, sometimes chuffing before coming fully up to pressure.