copperhead cluster question

[jerryb]

I have a question.. as I'm new to clustering... AND new to copperheads...

I just got my shipment of E30 engines in from Red Arrow Hobbies.. and noticed that the copperhead ignitors in the packages looked to only have one lead coming from it..

I've read that its possible to delaminate the leads and use standard alligator clips... but can you hook the leads up in series to light the cluster?? or am i courting distaster thinking this way?

I've also seen mentioned a "z fold" can someone explain this one?

thanks in advance...
Jerryb

 

[Ryan S.]

yeah tehre are actually 2 strips of copper with insulator in the middle. You can hold a match under the end w/o the pyrogen and they will come apart and you can hook them up normally.

Dont use copper heads for cluster, I wouldnt even use them in general

 

[solrules]

clustering would be very difficult to pull off with copperheads. You need a large battery (car, motorcycle) to light one reliably. More than one would really be pushing it, but it can be done.

If you were to cluster, Daveyfire brand igniters are the industry standard because they are very low current.

 

[jerryb]

Originally posted by solrules
clustering would be very difficult to pull off with copperheads. You need a large battery (car, motorcycle) to light one reliably. More than one would really be pushing it, but it can be done.

If you were to cluster, Daveyfire brand igniters are the industry standard because they are very low current.

ok... do those igniters require special clips for the launch system leads??

 

[UhClem]

Using a Copperhead is easy via several methods:

1) Use the Aerotech igniter clip
2) Use a butane lighter to delaminate the copper strips from the insulator.
3) Use masking tape to insulate the copper.


Method 3 is the most frequently used. You need two pieces of masking tape. Place them near the end of the igniter. One on one side, one on the other. But offset so that when you connect the igniter clips, each clip will only contact one side of the copper strip.


While Copperheads are not recommended for clusters, it can be done. You must first test the igniters to make sure that they are not shorted. This requires measuring the resistance along the wire. If the resistance is lower further away from the head, the igniter is shorted and should not be used. Your meter will have to resolve differences of less than a hundredth of an ohm and not every meter is up to this.

Then you connect each Copperhead to its very own relay box and activate all at the same time.

Not easy but it can be done.

Clustering E30's will be tough because the nozzle throat and the propellant slot are pretty small. Too small for low current E-matches.

If clustering AND Copperheads are new, then I strongly urge you to try several flights with just one composite motor and copperhead first. Then add the complication of trying to get a cluster to work. Clustering composites is not trivial.

 

[Bill]

Originally posted by UhClem
3) Use masking tape to insulate the copper.


Method 3 is the most frequently used. You need two pieces of masking tape. Place them near the end of the igniter. One on one side, one on the other. But offset so that when you connect the igniter clips, each clip will only contact one side of the copper strip.

I second what David said, with an additional suggestion. Look at the igniter clips and you will see two pieces connected by a hinge. Make sure the uninsulated side of the ingiter contacts the half of the clip attached to the wire from the relay, otherwise, the resistance of the hinge works against you. This hint is useful even when only one motor is used.


Bill

 

[SwingWing]

Originally posted by jerryb
I've read that its possible to delaminate the leads and use standard alligator clips... but can you hook the leads up in series to light the cluster?? Jerryb

Friends don't let friends cluster with copperheads!
When you do cluster, wire the igniters in PARALLEL, not series.

 

[cls]

AT makes "First Fire Jr." ignitors, Red Arrow might have those.


I've had excellent results (100%) clustering AT single use motors with FireFly ignitors. they are little so they will work with 18mm RMS too, which is notoriously difficult to ignite (spits out copperheads 2 out of 3 times).

call Performance Hobbies to order FireFlys. not sure if anyone else carries them.

 

[solrules]

Originally posted by cls
AT makes "First Fire Jr." ignitors, Red Arrow might have those.

First fire's still take alot of current, and are not recommended for clustering. Low current ematches dipped in pyrogen is the best way of doing it, even on the smaller motors.

On a side note, you can make a Jr. Igniter out of a Sr. (hehe) ignitor by simply unfolding the wire that is dipped in pyrogen. Must be very careful, as you can ruin your igniter if you do it wrong. This works because the first fires are folded, then dipped. If you unfold them, they should be small enough to fit in the e30 nozzle.

 

[jerryb]

one of the guys in our local club said he's had good luck with the FirstFire Jr's and AT E-30 engines... I'll see if i can grab some before the june launch... if not.. my custom will fly on E-9 BP motors..and I'll save the E-30's for the Estes V-2 i'm currently working on...

thanks for the advice
Jerryb

Originally posted by cls
AT makes "First Fire Jr." ignitors, Red Arrow might have those.


I've had excellent results (100%) clustering AT single use motors with FireFly ignitors. they are little so they will work with 18mm RMS too, which is notoriously difficult to ignite (spits out copperheads 2 out of 3 times).

call Performance Hobbies to order FireFlys. not sure if anyone else carries them.