New Aerotech Igniter Insulation Failure

[Oberon]

Yesterday I flew a 38-360 I245G motor. It came packaged with an igniter a bit different from the other FirstFires I’ve seen. The insulation was a different color, red and yellow, rather than the regular dark yellow. And it was softer and thinner.

When I went to launch, I had good continuity, but no fire after two attempts. At the pad, I noticed the igniter had not fired. However, the insulation had clearly melted along much of the length of the leads. Best guess is a short formed somewhere along the line due to the insulation melt before the tip got enough juice to go.

I saw several other discarded igniters from previous flights scattered around the pad. A few were this “new” Aerotech type, and all showed evidence of significant insulation melting (although the others had fired).

I replaced the dud igniter with a regular FirstFire I swiped from an older motor, and it worked fine. No significant melting along the wire.

Our club was trying out a new Wilson FX launch system with brand new leads and a ton of output potential, so clearly these are getting a lot of current. But it seems like the new igniter design is flawed if the insulation can’t handle the required “all fire” current for the igniter.

Anyone else had this issue?

 

[deangelo54]

I have NOT had this particular issue. I fly with a club that used the Wilson FX launch system and they have not had any issues with it. A couple of times I had issues with AeroTech igniters that came with single use engine. The igniters did not have any pyrogen. I took photos, sent them to AeroTech customer service and they replaced them. https://www.aerotech-rocketry.com/contact.aspx

 

[Steve Shannon]

Yesterday I flew a 38-360 I245G motor. It came packaged with an igniter a bit different from the other FirstFires I’ve seen. The insulation was a different color, red and yellow, rather than the regular dark yellow. And it was softer and thinner.

When I went to launch, I had good continuity, but no fire after two attempts. At the pad, I noticed the igniter had not fired. However, the insulation had clearly melted along much of the length of the leads. Best guess is a short formed somewhere along the line due to the insulation melt before the tip got enough juice to go.

I saw several other discarded igniters from previous flights scattered around the pad. A few were this “new” Aerotech type, and all showed evidence of significant insulation melting (although the others had fired).

I replaced the dud igniter with a regular FirstFire I swiped from an older motor, and it worked fine. No significant melting along the wire.

Our club was trying out a new Wilson FX launch system with brand new leads and a ton of output potential, so clearly these are getting a lot of current. But it seems like the new igniter design is flawed if the insulation can’t handle the required “all fire” current for the igniter.

Anyone else had this issue?

It’s more likely that there was already a short near the head that caused the wire to heat enough to melt the insulation.

 

[Oberon]

Steve, that was my thought too, but it doesn’t explain the melting on the other discarded igniters I saw. The insulation was definitely thinner and softer to sight and feel. Seems to be a marginal design relative to the older batches of igniters.

 

[Steve Shannon]

Steve, that was my thought too, but it doesn’t explain the melting on the other discarded igniters I saw. The insulation was definitely thinner and softer to sight and feel. Seems to be a marginal design relative to the older batches of igniters.

That could be. Pick up one of the used ones that show overcurrent damage sometime and check its continuity. It may be that the design remains continuous. Some ematches do that so they can be used in series.

 

[cerving]

I have had this happen at least twice with the igniters that came with the non-hazmat J520. The first time it happened it was a huge puzzle... the wires were clearly fried near the pyrogen, but the pyrogen never lit. I had a few extra igniters on hand so I didn't press the issue with Aerotech, but maybe I should have. When I get one of those igniters now, I always do a resistance check.

 

[Donnager]

The three single use Aerotech motors I used this summer (H125, H550, I435) had a 100% fail rate on igniters. All three required me supplying an alternate igniter. One had cracked, crumbling pyrogen, but the other two looked fine, just no start. Not planning to make three walks out to the pad to get one off the ground, re-checking, cleaning connections, etc., next time.

I didn't inspect the leads, but none burned any of the pyrogen on the launch attempts.

I'll be starting with fresh igniters on another H550 and an I-500, and throw the igniters from the package into my "sketchy spares" pile.

 

[Cameron Anderson]

New Aerotech igniters have very thin insulation and come shorted in many instances. They will show continuity because they are shorted but won't fire and often melt.

 

[cwbullet]

New Aerotech igniters have very thin insulation and come shorted in many instances. They will show continuity because they are shorted but won't fire and often melt.

We have a couple at our last launch and the insulation was thin or cracked and shorted to melt the wires without igniting. They were both Aerotech. They were replaced by me. I will send both an email and suggest they also contact the dealer.

I do not remember the motors or if they were the same propellant or batch. It did not occur to me until I saw this thread.

 

[Cameron Anderson]

We have a couple at our last launch and the insulation was thin or cracked and shorted to melt the wires without igniting. They were both Aerotech. They were replaced by me. I will send both an email and suggest they also contact the dealer.

I do not remember the motors or if they were the same propellant or batch. It did not occur to me until I saw this thread.

I've seen multiple bad ignitors in 29mm SU and 38mm RMS reloads.