Copperhead first then finsh the reload assembly?

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mpitfield

mpitfield

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Going to a local LP/MP launch tomorrow with the kids and I thought I would pull my AT 29/40-120 hardware out and pop up one of my MPR on an E23. This was my first hardware when I got into HPR and very quickly moved on to the individual 29mm AT hardware so my familiarity is sketchy at best. So I read over the instructions this evening to be better prepared and I was surprised to see that the instructions tell you to insert the copperhead igniter, then the nozzle, followed by the o-ring and the aft closure.

No I realize this is MPR but it goes against everything I have learned up until now, which is insert the igniter on the pad. Are these instructions correct, the reload is about 2 years old, if so is there something special about the copperhead igniter that makes it more safe? I checked the nozzle and you actually have to insert the igniter first as the throat is not as wide as the business end of the copper head, so you couldn't assembly it another way.
 
It's purely because it won't fit in the nozzle after assembly. You can assemble with the copperhead in it, it'll be safe-ish, per the directions.
Personally I would avoid the whole thing and just use a different starter. My luck with copperheads is... Nil.
 
I almost always have to build my igniter into the hobby reloads, no matter which kind I use.
 
jimzcatz said:
I almost always have to build my igniter into the hobby reloads, no matter which kind I use.
Click to expand...

Yep, What he said. Even the smallest magnelite starters have to be built into the motor during assembly. My copperhead luck is less than 50%, and I had the special clip.

Adrian
 
Being pretty new to composite reloads, I've only used my 40-120 a dozen times or so. Only had the Copperhead not light it once. But on that time I was able to get an Estes Sonic igniter in there with no problem.
 
Yep, put them in and complete assembly. I then short them with a piece of aluminum foil and a clothes pin until it's on the rail. Just makes me feel better.
 
When I fly on my own (meaning not at a club launch or event), I pretty much always insert copperheads during motor assembly. While certainly not my favorite type of starter/ignitor, if they come with the motor I'll use them, and they work just fine "most" of the time. I won't use them for complex clusters or anything like that, but for regular old woosh-pop MPR flights, it would be silly to waste them.

If I'm flying at a club launch/event, I ALWAYS check with the RSO ahead of time regarding inserting during motor assembly. Go with whatever they advise. If they are fine with inserting ahead of time, then no problem. If they want you to short it somehow (like T-Rex does in the above post), then do it. If they stick to the rule of ONLY inserting ignitors when on the pad and ready to fly, follow the rules and don't argue.

s6
 
+1 Estes Sonic lighting hobby AT loads. +1 insert igniter at the pad. +1 Copperheads are a waste of time and effort.
 
The requirement to insert the igniter at the pad is for high power, at least in NAR.
 
You can insert copperheads at the pad. It is just easier to do it during assembly.
 
I always preferred having an igniter installed during the build, but many launches do not allow an igniter installed until you get to the pad (or at least that was the way it was several years ago).

Like many, I did not particularly care for Copperheads, but I've had OK results with smaller ones on black powder Quest motors. For small diameter nozzles, I've built my own using small (26ga.) twinlead and Firefox Enterprises Liquid Element (SECPLEL), a conductive pyrogen. No bridge wire required. For black powder, the Liquid Element alone works great. For composites, a second dip in something like their Magnum Secondary Pyrogen (SECPMAG), giving a longer burn time and bigger spark.

This technique can yield very compact igniter "heads", and fit small motors like the 24/40 and 29/40-120 hardware quite nicely.

Here is the link to the "Ignition" page on Firefox website: https://www.firefox-fx.com/ignition.htm
 
NFPA 1127 iirc no igniters will be placed in motors "G" impulse or larger prior to being on the pad, so its not just HPR that has to be inserted at the pad, "F" and lower probably depends on your club.
 
rharshberger said:
NFPA 1127 iirc no igniters will be placed in motors "G" impulse or larger prior to being on the pad, so its not just HPR that has to be inserted at the pad, "F" and lower probably depends on your club.
Click to expand...

NFPA 1127 only applies to HPR. The G impulse reference would be for HPR versions of G motors (ie those that have characteristics that exceed Model Rocket Motor limits).

Copperheads require a lot of current to fire. Other HPR igniters may be much more sensitive and could fire with low current or a styic discharge, hence the extra safety precaution for HPR.

Also, HPR motors are often BATES grains so installing an igniter at the pad is absurdly simple.
 
You are correct Fred. NFPA 1127 does specifically apply to HPR, as far as my local club is concerned any "G" motor is treated like HPR and the igniter is required to be inserted on the pad. It avoids confusion.
 
If the mfg instructions say to install the igniter during assembly, then you can do so with out getting in any trouble. Like Fred stated, the install at the pad rule, is for low current igniters, such as a Davey Fire, or J tec, that are sensitive to static discharge. Plus, with the copperheads, finding that little c slot can be difficult enough at times, to cause a delay at a launch while a flier is trying to get it installed at the pad (don't ask how I know this).

David
 
I prefer to install the igniters for my 24mm & 29mm AT reloads on the pad and have used (non-Copperhead) AT & Estes Pro Series igniters without a problem yet in over a dozen launches. Also inserting them isn't a problem as long as there isn't bent wire or a bent tip. The trick is after you've assembled the reload, place the igniter against the outside of the motor to determine how long it has to be inserted into the motor up to the delay (if instructed) and then bend the wire where the motor nozzle is, that is your marker that you've inserted the igniter all the way in otherwise you're just guessing when you're inserting it at the pad. 18mm reloads are quite small (and rare), so the RSO should understand if you have it assembled with the igniter installed, but I'd suggest twisting the igniter ends together as an extra precaution against some strange mishap.

Also I'd highly recommend having extra igniters on you if you practice installing on the pad...all too often I get to the pad and then realize I forgot the igniter I was going to bring, but luckily I had extras in my cargo pockets. :)
 
It's a copper head, it safe - they never work. :rolleyes:

But in all seriousness, multi stage rockets require igniters to be installed prior to being placed on the pad as do some motors. These are to be installed in the preparation area and this is within the rules. Taking a motor and/or rocket apart on the pad is far from ideal and could lead to issues that would potentially be a safety hazard.
 
KenECoyote said:
I prefer to install the igniters for my 24mm & 29mm AT reloads on the pad and have used (non-Copperhead) AT & Estes Pro Series igniters without a problem yet in over a dozen launches. Also inserting them isn't a problem as long as there isn't bent wire or a bent tip. The trick is after you've assembled the reload, place the igniter against the outside of the motor to determine how long it has to be inserted into the motor up to the delay (if instructed) and then bend the wire where the motor nozzle is, that is your marker that you've inserted the igniter all the way in otherwise you're just guessing when you're inserting it at the pad. 18mm reloads are quite small (and rare), so the RSO should understand if you have it assembled with the igniter installed, but I'd suggest twisting the igniter ends together as an extra precaution against some strange mishap.

Also I'd highly recommend having extra igniters on you if you practice installing on the pad...all too often I get to the pad and then realize I forgot the igniter I was going to bring, but luckily I had extras in my cargo pockets. :)
Click to expand...

Just to be clear, when I said "I prefer to install the igniters for my 24mm & 29mm AT reloads on the pad", I DO NOT remove the motor from the rocket...I just insert the igniter in through the nozzle end while the motor is already in the rocket. I haven't had issue with any of the AT reloads I've done this way. Of course you have to make sure the grains are taped aligned and also be sure that the nozzle hole is cleared (as noted in the instructions).
 
Well it was an interesting launch, which I will get to in a bit.

First off for those who advised to install it at the pad I was perhaps not clear on my original post. Installing once the motor is assembled is not possible with the copperhead and this particular motor. This is simply because the copperhead (head) is much wider than the throat of the nozzle, so it has to go in first then the nozzle over the end. I am not sure the diameter of the nozzle but it is small.

So here is the interesting part, the motor CATOd right off the launch rod. The copperhead worked without any issues and as the rocket just left the rod it split in two due to the gasses from the motor, then cartwheeled and hit the dirt. Remarkably the rocket was pretty much unharmed a few scratches and I launched it twice right after.

Visually it appeared to of ignite from both ends, almost immediately. Looking at the nozzle it was off to the side and lose but this was after the failure. If I did not assemble the motor myself I would conclude that it was missing a spacer, o-ring, or was not tight. That was generally the initial thought by others who witnessed it, however they all scratched their heads when we dissembled it and saw everything in its correct spot and the case tightly closed.

All is well that ends well.
 
I have also heard of many issues with the Copperhead igniters and luckily I haven't had to use them. Instead, I make sure I have a good supply of other igniters which I know and trust, can fit into the nozzle end and not have to worry about how to clip on the wires. The 29/40-120 reloads I have from last year also note to install the igniter first in the instructions; however none of them come with Copperheads...probably tells you something about the Copperheads.

Sorry to hear about the CATO...never good news, but luckily no one hurt and the rocket sounds good. I've heard of this type of CATO before, but can't recall what others said was the possible cause. Leaving out the delay would be an obvious one, but very unlikely from the sound of things. Did you reuse the same casing after the CATO?

BTW - Was it one of the EZ delays? I've heard of some having issues with those...
 
mpitfield said:
Well it was an interesting launch, which I will get to in a bit.

First off for those who advised to install it at the pad I was perhaps not clear on my original post. Installing once the motor is assembled is not possible with the copperhead and this particular motor. This is simply because the copperhead (head) is much wider than the throat of the nozzle, so it has to go in first then the nozzle over the end. I am not sure the diameter of the nozzle but it is small.

So here is the interesting part, the motor CATOd right off the launch rod. The copperhead worked without any issues and as the rocket just left the rod it split in two due to the gasses from the motor, then cartwheeled and hit the dirt. Remarkably the rocket was pretty much unharmed a few scratches and I launched it twice right after.

Visually it appeared to of ignite from both ends, almost immediately. Looking at the nozzle it was off to the side and lose but this was after the failure. If I did not assemble the motor myself I would conclude that it was missing a spacer, o-ring, or was not tight. That was generally the initial thought by others who witnessed it, however they all scratched their heads when we dissembled it and saw everything in its correct spot and the case tightly closed.

All is well that ends well.
Click to expand...


I wonder if the Crapperhead after igniting the motor instead of blowing clear, plugged the nozzle overpressuring the case (WAG on my part). I know one member of our club makes special igniters just for those tiny nozzled loads.
 
by any chance did you have to adjust the delay? and did you have the spacers(propellant and delay) facing the right way? blue thunder puts a lot of stress on the O-rings...sounds like you had one fail to maintain a seal.
Rex
 
KenECoyote said:
BTW - Was it one of the EZ delays? I've heard of some having issues with those...
Click to expand...

This is the reload, although the pic is not completely correct as there were 3 0-rings, two large one small and only one grain, but it was a slot. https://www.allrocketengines.ca/Reloads/29-Hobby-Line/E23-5T

And the hardware is the RMS, here https://www.allrocketengines.ca/RMS/29-40-120?zenid=5ge605hc2camhens0ppbi4eem0

rharshberger said:
I wonder if the Crapperhead after igniting the motor instead of blowing clear, plugged the nozzle overpressuring the case (WAG on my part). I know one member of our club makes special igniters just for those tiny nozzled loads.
Click to expand...

The nozzle is very small so I suppose that is a possibility, one I did think of.

Rex R said:
by any chance did you have to adjust the delay? and did you have the spacers(propellant and delay) facing the right way? blue thunder puts a lot of stress on the O-rings...sounds like you had one fail to maintain a seal.
Rex
Click to expand...

I did adjust the delay to roughly 4 seconds. There was a spacer/insulator at the top, the small o-ring the delay grain with the insulator and spacer, then the washer spacer the grain insulator with the smaller diameter spacer, the grain on the bottom the nozzle and another o-ring. The top of the grain was tapped with tape overlapping the sides of the grain then pushed into the insulator to prevent the igniter from going past the top of the grain. I may not be regurgitating it correctly but it was disassembled on-site and it was confined correct at the time.
 
rharshberger said:
I wonder if the Crapperhead after igniting the motor instead of blowing clear, plugged the nozzle overpressuring the case (WAG on my part). I know one member of our club makes special igniters just for those tiny nozzled loads.
Click to expand...

I think this is a very possible issue since it was already mentioned that they don't fit through the nozzle after assembly, so there's always that chance it won't fit through after starting the motor. May also explain AT replacing them with regular igniters in the dozen+ 29mm reloads I've gotten this year and last. Again, I prefer to use the ones I like and trust and fit through the nozzle after assembly. :)

BTW - I was looking up another nearby (U.S.) rocket club today and just saw their range rules list this: "No igniter is to be installed in a High Power/mid power rocket motor until the rocket is on the pad pointed up."
 
Last edited:
Well, at least the Copperhead lit. :wink:

Did the rocket zipper?

What caused the NC to eject? Doesn't look like a charge lit...
 
I've always thought copperheads were the best. Incredible for lighting composite and BP. They make awesome DD matches. And the reliability beats anything I've seen.

And that's the story I'll tell the day my kids truly do drive me crazy. I will admit I've had 100% success on my copperheads, but I haven't used that many. I'm chalking it up to pure luck based on what I've heard. A pack of first fire jr. Are not that much and way more reliable than people say about the copperheads.
 
KenECoyote said:
BTW - I was looking up another nearby (U.S.) rocket club today and just saw their range rules list this: "No igniter is to be installed in a High Power/mid power rocket motor until the rocket is on the pad pointed up."
Click to expand...

I'm all about safety. But club rules should not be able to override manufacturer instructions. As a matter of fact, failure to properly follow the assembly instructions could result in a failure of the NAR insurance to cover an accident. The club needs to add a clause about "unless otherwise required by the manufacturer".
 
That's REALLY odd...doesn't look like a CATO, as there's no smoke out the top of the tube...

With the E and F loads in that case, you need to put a piece of tape at the top of the grain to keep the igniter from lighting the delay first as the propellant does not entirely fill the case. If the igniter extends past the top of the propellant grain and is sitting against the delay grain instead of the propellant grain, bad juju can happen...
 
Did the motor chuff any before coming up to pressure? Looking at your pics, it does appear the ejection fired right as the motor came up to pressure. If you built it stock, with the baffle in place, little if any smoke would have made it through the baffle. I also wonder if it's possible that the delay grain suffered a small crack during drilling.

David
 

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