Copperhead for clustering? What should I use

[ScrapDaddy]

I'm going to be building a large payloader rocket powered by 5x 18mm motors
but the instructions on the D21 and D10 say EXPLICITLY NOT to use copperheads for clusters besides useing the estes bp motors are there any other igniters out there? The only one I have in mind right now is the Q2G2 or the....... Ummmm..... Ok so just the Q2G2 anything else?

 

[ScrapDaddy]

Oh and asumming I was clustering 29mm motors (which is highly unlikely because they have immence power on their own, which igniter would I use?

 

[cjl]

For 18mm motors, you're pretty much on your own. Q2G2 might work, but I'd test it out with a single motor flight first to see if they were able to reliably light the motor. 29mm clustering is much easier. The Aerotech FirstFire Jr would work great, as would any of the standard 2 wire igniters available. You could also dip your own using something like QuickDip or Magnelite.

 

[MarkII]

What are you trying to boost? Five D10s or D21s is equivalent to a G motor.

Burning five D10s at once will cost approximately $26, and will deliver G impulse.

Burning five Estes C6s at once will cost around $7, and it will deliver F impulse.

Is achieving G impulse with a cluster of motors worth spending more than three times as much as you would spend to achieve F impulse with the same number of motors? Especially when it will be much easier to ignite the F cluster than it will be to ignite the G cluster?

Either Aerotech First Fire Jrs. or Quest Long Lead Q2D2s can be used to ignite any of the clusters that you mentioned. Compared to Aerotech's igniters, the Quest igniters are significantly less expensive. If you want to use the Quest igniters, make sure that you obtain the Long Lead version.

The Aerotech F23FJ is the smallest 29mm single use motor available. A cluster of five of them is equivalent to an H motor. You would need to have high power certification if you wanted to launch a rocket with that cluster.

MarkII

 

[Micromeister]

I'm with ya Mark!
I'd much rather cluster a bunch of BP motors than a single AP. but that's just me.
As far as the answer to ScrapDaddies questions tho if you can't use the new Q2g2's in the 18mm AP's you'll have to make your own. Anythings including not flying the thing is better then trying to cluster with copperheads.

 

[luke strawwalker]

What are you trying to boost? Five D10s or D21s is equivalent to a G motor.

Burning five D10s at once will cost approximately $26, and will deliver G impulse.

Burning five Estes C6s at once will cost around $7, and it will deliver F impulse.

Is achieving G impulse with a cluster of motors worth spending more than three times as much as you would spend to achieve F impulse with the same number of motors? Especially when it will be much easier to ignite the F cluster than it will be to ignite the G cluster?

Either Aerotech First Fire Jrs. or Quest Long Lead Q2D2s can be used to ignite any of the clusters that you mentioned. Compared to Aerotech's igniters, the Quest igniters are significantly less expensive. If you want to use the Quest igniters, make sure that you obtain the Long Lead version.

The Aerotech F23FJ is the smallest 29mm single use motor available. A cluster of five of them is equivalent to an H motor. You would need to have high power certification if you wanted to launch a rocket with that cluster.

MarkII

Amen Mark-- I'm waiting to see the answer for this one... choosing to cluster that many smaller reloads versus the BP motors might qualify him for NASA (mis)management on the costs alone...

You're seriously contemplating a cluster this expensive when in another thread you say you can't afford to buy a set a commercial parachutes?? :confused2:

OOOO Kayyyyy... :eyepop::confused2::roll::roll::roll:

Later... OL JR

 

[ScrapDaddy]

I was just wondering in a hypothetical situation and whwmere did u get the parachute thing

 

[hardinlw]

Clustering composite motors is an iffy thing. They generally take longer to come up to pressure than BP and that might mean that you would get liftoff with some motors unlit or just coming up to thrust. My experience is that the Blue Thunder propellent is the easiest to light and Black Jack the hardest. You would want a hot igniter, but not one so large that it would get jammed in the nozzle and cause a CATO. Also, you want to be sure that all igniters are pushed all the way to the top of the motor. I think some people have mentioned painting igniter pyrogen on the grains to make them easier to light, but I've never done that, nor have I attempted a composite cluster having seen a couple of "less than successful" attempts at clustering composites.

 

[The EGE]

Clustering composite motors is an iffy thing. They generally take longer to come up to pressure than BP and that might mean that you would get liftoff with some motors unlit or just coming up to thrust. My experience is that the Blue Thunder propellent is the easiest to light and Black Jack the hardest. You would want a hot igniter, but not one so large that it would get jammed in the nozzle and cause a CATO. Also, you want to be sure that all igniters are pushed all the way to the top of the motor. I think some people have mentioned painting igniter pyrogen on the grains to make them easier to light, but I've never done that, nor have I attempted a composite cluster having seen a couple of "less than successful" attempts at clustering composites.

Black Jack is definitely hard. I had one F12J reload that took three perfectly good Copperheads to light. Turns out the ignition system wasn't delivering a full 12V, so they wouldn't go off fast enough and ignite the motor.

 

[ScrapDaddy]

Copperheads have their reputations

 

[The EGE]

Copperheads have their reputations

It wasn't the Copperheads that were a problem; it was the ignition system.

Copperheads are decent igniters, though they have their problems; they just require a solid hookup - preferrably with the clip - and 12V at a decent current.

 

[cjl]

Copperheads tend to only give a short puff of flame, which is often insufficient with the harder-to-light propellants. Some of the better igniters burn for longer, which is why they work for the Blackjack and similar propellants.

 

[Handeman]

Copperheads tend to only give a short puff of flame, which is often insufficient with the harder-to-light propellants. Some of the better igniters burn for longer, which is why they work for the Blackjack and similar propellants.

Now that you mention it.... I've only had about one failure a year with copperheads, but I do seem to recall that most of them are with Blackjack propellant. I usually try the included copperhead and if it doesn't work, I'll use one of my homemade iginters. They always work. Maybe I should just use one of them first.

 

[ScrapDaddy]

I am declaring Copperhead. A pain in the butt to ignite.... I'd need a 120 v outlet system to cluster them..... Anyone have a motor home? For the record I'm just kidding

 

[MarkII]

I am declaring Copperhead. A pain in the butt to ignite.... I'd need a 120 v outlet system to cluster them..... Anyone have a motor home?

Don't go beating up on Copperheads; plenty of people use them successfully all the time. But they are definitely not recommended for use in clusters or airstarts - as Aerotech says themselves in their instructions.

MarkII

 

[ScrapDaddy]

Sorry copperheads i had a diva moment awww now who's a good copperhead... You are! Awwww now invite the motor in 3 2 1..... Now ignite! ... I said ignite!!!! Grrrrr! Bad copperhead now it's tim out time!

 

[MarkII]

Fine. Why don't you tell all the good people tuning in just how many times you have used Copperhead igniters to light motors, Mr. Expert.

MarkII

 

[rokitflite]

Come on Scrap, each day when I click "New Posts" there is yet another thread with you asking questions... From semicolons to Honest John nose cones and from 18mm motors to night flyers. When are you gonna take all of this knowledge you have collected and show us a build thread or something?

 

[ScrapDaddy]

I'm a little.....dry on funds :blush:right now...

 

[rseazk5]

I am getting ready to launch my first composite cluster and would like everyone's advice to ensure I am succesful. I have a 2 motor cluster using E20-7W. I am planning to use the FirstFire igniters that come with the motor unless you tell me otherwise.

Launch pad power should not be a problem - 12 Volt small car battery.

Anything concerns or recommendations?

Thanks,
Ray

 

[scsager]

I am getting ready to launch my first composite cluster and would like everyone's advice to ensure I am successful. I have a 2 motor cluster using E20-7W. I am planning to use the FirstFire igniters that come with the motor unless you tell me otherwise.

Launch pad power should not be a problem - 12 Volt small car battery.

Anything concerns or recommendations?

Thanks,
Ray

I would think that the FirstFire igniters that come with the motor should be fine, make sure to hook-up in parallel, not series.

 

[Zeus-cat]

If you attempt to cluster on copperheads I recoomend you have a priest attend the launch. First to bless the rocket before the launch and then to perform the burial of what's left afterwards. :bangpan:

 

[Rocketcrab]

If you attempt to cluster on copperheads I recoomend you have a priest attend the launch. First to bless the rocket before the launch and then to perform the burial of what's left afterwards. :bangpan:

This is exactly what my resonse was when one of our club members flew a model on two G80's using copperheads. To everyone's shock, it worked. Then just to show off, he did it again! :confused2:

 

[ghrocketman]

Clustering crapperheads is just ASKING for trouble.

 

[Handeman]

Clustering crapperheads is just ASKING for trouble.

I'm not sure I agree with that. I've had very good luck with copperheads. I always sand the c-slots and leave the dust in place. I only had 6 or 7 failures since 2003 and if I recall correctly, most of those were Blackjack propellant. I'm not sure that is any worse then what any other igniter might be. I would certainly use copperheads in clusters of Hobbyline motors, especially if the rocket is 200 ft out on the HP pads.

If you have had a lot of problems with copperheads, then I would also recommend you don't use them since those problems will probably occur in the clusters too. I do think that sanding the grains, how the electrical connections are done, etc. all affect the reliablility of copperheads. Some peoples techniques work well, other, not so much.

 

[MarkII]

AeroTech states that Copperhead initiators should not be used for clustering. EDIT: Oops! You mentioned that already way back in your original post. Never mind...

 

[The EGE]

Bite the bullet, drop 5 bucks for a Copperhead clip. (Then, take a sharpie and put your name on it, because you will leave it on the pad). I have had 100% success with mine... when I assembled the load correctly.

 

[MarkII]

And don't do what I do, which is to completely forget to go back and retrieve the clip until after the launch site has been taken down. You'll need to buy a lot of clips if you do.

 

[Handeman]

And don't do what I do, which is to completely forget to go back and retrieve the clip until after the launch site has been taken down. You'll need to buy a lot of clips if you do.

That's why I make a half dozon from clothes pins and 16 ga. stranded copper wire I had laying around, $0.00. Haven't had a missfire yet.

 

[Micromeister]

Sorry but i'll have to say my experience and observations of Copperhead and Tigertail igniters over the years has been poor to absolute CRAP. At last months sport launch I counted more then 5 Copperhead failures from very experienced AP flyers.
Of all the igniters I've seen and tried over the years Both Aerotech Copperheads and Quest Tigertails have proven to be the LEAST reliable of anything ever produced. They have to be the worst designed product for the purpose out there. I'm constantly amazed Aerotech hasn't redesigned or come-up with a new igniter after hearing all the trouble folk have with them. Perhaps a more positive way of checking for slicing shorts (the number one cause of failure) as well as anti-bending protection (the number two failure source).
In any case they should NEVER be used in any cluster or air start application.