Copperheads & Aerotech...any tips?

[caheaton]

Hello, was out at the park yesterday and finally got to fly my Onyx...beautiful flight on an F20-4 Econojet. My question for the group is this...my wife & I had a devil of a time trying to get the ignitor inserted into the slot in the propellent grain. Took us nearly half an hour for the F25-6 motor I had hoped to use for a second flight (but then the ignitor turned out to be bad so we gave up!). As it stands now, trying to insert the ignitor is like trying to push a wet noodle it just wants to bend rather than go into the slot and several ignitors had the pyrogen fall apart trying to get them inserted. Does anybody have any tips they care to share on how this process might be made a little easier? Any tools you use? Other brands of ignitor to consider? Thank you!
Craig

 

[Crazyrocket]

When I use copperheads, I just hold the igniter near the head and slowly push in while rotating the motor to find the slot. If you push too hard, you run the risk of shorting out the igniter. I also run the edge of a sharp blade along the edge of the igniter to remove any small microshorts.

In the past, I have used Quickburst igniters, but they are are undergoing some regulatory problems right now.

The other area you need to pay particular attention is the end where you connect your leads. If you are using aligator clips with teeth, then you really need to be careful not to damage the thin copper coating. By being careful, I can usually get 80% reliability (maybe as much as 90%), but it does stink when you have to change out igniter, especially when kids are watching. Good luck.

 

[shreadvector]

Already answered on r.m.r. 9where you asked the same question.

Shall I cut & paste the response here?

 

[mr_fixit]

Originally posted by shreadvector
Already answered on r.m.r. 9where you asked the same question.

Shall I cut & paste the response here?

Please do! Thanks!

Tom

 

[shreadvector]

If the accordion folded tip is not completely covered in pyrogen, it can flop around (wet
noodle) and be annoying to insert. if you get one with pyrogen completely covering the
accordion folded area and just below, the pyrogen stiffens it and allows it to be inserted
easily.

Notify Aerotech of your igniter difficulties. If you got defective igniters, they should
send you replacements.

Magnelite pyrogen on thin wires with nichrome wire at the tip works great for me as a
replacement igniter.

https://www.rocketflite.com/products.asp

-Fred Shecter NAR 20117

Originally posted by mr_fixit
Please do! Thanks!

Tom

 

[thejohnchapman]

I know that others have had different experience, but I have NEVER had a copperhead fail to ignite the motor. That includes cases where I had no 12 volt system, and so used two 6 volt Estes electrical systems in series.

Still, I see failures reported everywhere. Maybe I'm just lucky.

 

[dcastle]

Originally posted by thejohnchapman
I know that others have had different experience, but I have NEVER had a copperhead fail to ignite the motor. That includes cases where I had no 12 volt system, and so used two 6 volt Estes electrical systems in series.

Still, I see failures reported everywhere. Maybe I'm just lucky.

Oh oh...bad choice of words.....

I had the same experience too -- a couple dozen, more or less, flights using copperheads, never a problem.

Then I made the mistake of telling the guys in the club at the launch that "I don't see what the problem is, copperheads always work for me..."

Next launch up was my Arreaux, copperhead igniter...nothing, just some smoke. Swap out the igniter...again...then another...again...a fourth...still no luck. Finally one of the guys gave me one of his own home-dipped ignitors...perfect launch...

Copperheads have a way of biting if you don't watch it...

 

[astrowolf67]

I agree Dan, I use to have at least a 90% success rate, till I bragged about it. Now, I'm lucky to have a 10% rate. Once my luck ended, it didn't take long for me to start dipping my own.

Craig, I turn the nozzle end up, straighten out the igniter, and just start turning the motor slightly while dropping the igniter into the nozzle, you'll know when you've found it. For better fire rates, if you don't have an interlock clip from AT, use a lighter on the end opposite the pyrogen tip to separate the two leads Attachh your clips, and put a piece of masking tape between them to keep them from shorting out. Also, don't use the rubberband, or red cap to hold the igniter in, use a piece of tape. If you cover the nozzle with the tape, poke a small vent hole in it.

 

[caheaton]

I think I've got it! Tonight I tried inserting the ignitors from home, and found that if I use my laser pointer to first spot the slot, then mark where that slot is with my finger, I can slide the ignitor in. Much easier if I can see where the slot is and what angle of attack I need for inserting the ignitor. (I use the laser pointer as it gives me a nice bright spot on the propellent grain that seems to illuminate the entire grain.) Think what I'll do is just pre-insert ignitors into the motors I plan to use that day as a time saving measure.

My thanks for all the replies...I do have an AT clip, but I actually find tape on my micro clips (smooth jawed) seems to work better. I can get the clips on more quickly without undue bending of the fine copper ribbon. I'm intrigued by the Magnelites, though. I just might make up a batch by dipping the pyrogen onto coils of very fine nichrome wire. Might make for a smaller ignitor that is easier to insert for the times that the slots give me trouble. Should also be more reliable for clustering too.
Craig

 

[Brian62]

No Craig! You do not want to preload your ignitors! I believe that is one of the golden rules of rocketry...to only install at the pad.
I also replied a different answer on quarkers.
Brian.

 

[caheaton]

Point well taken, Brian. I honestly don't feel it is too much of a safety hazard given my motor storage, but I can see the point. Guess what I'll do instead is just mark on the motor body with a pencil where the slot is. That should get me close enough for inserting the ignitor when out in the field.
Craig

 

[terryg]

I hardly ever use copperheads since I dip my own hellfire ignitors.
However. I think the success rate depends on the engine you are using. For what ever reason they have worked for me on single use engines. On reloads, if the slot in propellent is narrow they work better then if the slots are wide (higher impulse). Also the type of propellent effects this also, black jacks are hard to ignite so trying to use copper head to iqnite them can be frustating. They allways ignite for me, but do not have enough umph to light the propellant.

 

[2muchstuff]

Originally posted by caheaton
I think I've got it! Tonight I tried inserting the ignitors from home, and found that if I use my laser pointer to first spot the slot, then mark where that slot is with my finger, I can slide the ignitor in. Much easier if I can see where the slot is and what angle of attack I need for inserting the ignitor. (I use the laser pointer as it gives me a nice bright spot on the propellent grain that seems to illuminate the entire grain.) Think what I'll do is just pre-insert ignitors into the motors I plan to use that day as a time saving measure.

I can just see it now:

"Man injured when rocket motor is accidently ignited by laser pointer!"

(Just kidding of course.) Actually, you've pretty much got it. If you know where the slot is, you can get the ignitor in without much trouble. The big trick is on the those smaller motors is that the c-slot is offset from the center of the nozzle, so you have to 'angle' the ignitor into place. You can use a silver autograph marker (like a sharpie, but with silver ink) to mark on the nozzle where the slot is. Much easier to see at the field.

The other thing to do is to know how deep into the motor the ignitor should go. That way if it binds as it's being inserted, you'll know. For reasons I don't completely understand, if the ignitor is not all the way in, it can cause a motor to CATO. (There are some exceptions to this rule - mostly very long, thin motors, like the Ellis I69)

You don't want to store or transport motors with ignitors in them. Big no-no. (Especially for motor manufacturers.) Just mark the slot location and you'll be fine.


tms

 

[Rockaholic]

Originally posted by caheaton
Hello, was out at the park yesterday and finally got to fly my Onyx...beautiful flight on an F20-4 Econojet. My question for the group is this...my wife & I had a devil of a time trying to get the ignitor inserted into the slot in the propellent grain. Took us nearly half an hour for the F25-6 motor I had hoped to use for a second flight (but then the ignitor turned out to be bad so we gave up!). As it stands now, trying to insert the ignitor is like trying to push a wet noodle it just wants to bend rather than go into the slot and several ignitors had the pyrogen fall apart trying to get them inserted. Does anybody have any tips they care to share on how this process might be made a little easier? Any tools you use? Other brands of ignitor to consider? Thank you!
Craig

Okay, the solution is simple:

1. Get an xacto knife and carefully scrape both sides of the ignitor. This will help to remove any rough edges that could cause it to short out.

2. Buy the Aerotech Clip and only use them.

3. And this is the most important, it will guarantee your success: throw away the ignitor and clip and buy another brand of ignitor (e.g. quickburst)

Dave

 

[metalwizard]

i have lit litterly thousands of copperheads, with very good results. and i do mean thousands!!

if it wont fit in the slot because its too big dont be fraid to sand them lightly. just be careful to not sand the copper.

also remeber some copperheads are dipped once some are dipped twice depending on the motor is going in, dont mix them up!! make sure you use the one that came with the motor!

use either aerotech interlock or aligatorclips that have NO teeth on them.

and lastly several people said i got smoke but the motor didnt light, well thats not the ignitors fault thats may be the motors fault. keep your motor sealed in the package as long as possible. white lightning especially! it tends to absorb moisture, witch can cause difficulties (although rare)

if its an RMS make sure the spot were the igniter contacts is rough, a litlle sandpaper goes a long way!!

 

[roadkill]

Yea,

Sometimes the crapperhead can be a pain in the neck,
but in general I've had a rather good success rate...

It helps turning the motor so you get some bright sunlight
inside the nozzle and most of the time you can see where
the c-slot is... Patience and a gentle touch, but the more you play with them, the easier it'll get.

For power source I use the 'Yawning Yoda' method;
popping the hood in our truck and hooking up
the wires directly to the big battery usually makes even
the BlackJacks light up in a snap...

...except on one damp day, when mr.Murphy
was my co-LCO and nothing worked right...

 

[cls]

... on those days when Murphy is your LCO, maybe it's better that things don't launch, Murphy would get a bigger chance then.


I've had pretty good results with Copperheads. The Aerotech yellow clip works great to get a good connection. but the biggest source of trouble is from the rocket sitting on the pad, the weight of the wires pulling, the wind blowing, twisting the copperhead, pulling it out of the motor ... all that causes a lot of misfires. consequently, we generally use other ignitors, just to avoid a recycle and other aggravation.