tips for solderless ignitors

[rocketsonly]

Does anyone have any specific tips for using solderless ignitors? I have a huge launch coming up and I don't want to disappoint anyone. I've only launched one motor with a solderless igniter. The first time I pressed the button, the igniter didn't ignite the motor, but then I replaced it and the second igniter did.

 

[AlexM]

Are you doing a cluster, or is it a single engine?

 

[rstaff3]

Which type are you using?

 

[rocketsonly]

Originally posted by AlexM
Are you doing a cluster, or is it a single engine?

It'll be a two motor cluster.

 

[rocketsonly]

Originally posted by rstaff3
Which type are you using?

Method or pyrogen? For method, we're using the one found on Info Central where you wrap nichrome around two leads. For pyrogen, we're using Magnelite.

 

[n3tjm]

My Tip - Don't . It takes a little longer to solder, but you will have a lot more consistancy with the ohm rating of the igniters. If the ohm gets to high, the ingniters will pop instead of burn. I've made wires both ways, I never had to throw away an igniter I soldered.

 

[rstaff3]

Originally posted by rocketsonly
Method or pyrogen? For method, we're using the one found on Info Central where you wrap nichrome around two leads. For pyrogen, we're using Magnelite.

That's what I was looking for. I have never had a failure with a magnelite igniter and have only hand wrapped one, which also worked. As Doug says, the soldered ones (like magnelite's) will be more uniform. Uniformity is important in clustering.

 

[aksarben10]

I have made more then 100 of the wire wrap ignitors using my own pyrogens. I have had a very low failure rate as only a couple have failed, but these were all high current versions. One of them I dipped the wrong end, my bad.

For a cluster I would go with some low current ignitors. What gauge nichrome are you using? That will make a big difference in how quickly they ignite.

Also, I guess that I am assuming that you want to light AP motors if not there are other options but these will work.
For wire wrap I use 30 or 32 gauge wire because it is easy to work with. The downside is that they can be slow to start and I would not use them on a cluster as the times will very from ignitor to ignitor. For a lower current ignitor and a quicker start you need a smaller gauge wire at least 40 or better. When you get that small wire wrap does not work and you will have to solder.

I am working on low current ignitors next, these will be soldered chips with 50 gauge nichrome. I am hopeing that they will work with my timer and alt.


Scott

 

[Stymye]

make them how you like, just match them up with a meter first. the meter is your friend, not necessarilly the technique.or the brand

check them before you dip
check them after you dip
check them before you stick them in the motor
check and match them for clusters.

 

[wwattles]

Originally posted by stymye
make them how you like, just match them up with a meter first. the meter is your friend, not necessarilly the technique.or the brand

check them before you dip
check them after you dip
check them before you stick them in the motor
check and match them for clusters.

I agree. I checked all of mine throughout the process, and discarded/restarted any that went bad. When the last dip was done, I put a piece of tape on the ignitor-clip end and marked the resistance. Makes it easy to go through the box and find 2 or 3 that are all matched to within an Ohm of each other.

WW

 

[rstaff3]

I go thru the same measuring process, but don't mark them. DUH how could I miss the obvious? Good tip! I segregate them in my igniter box..ok if I do it the day before launch, not so good if I have to remember my sorting scheme a month later