Igniter FAQ?

I am looking for information about igniters, E-matches and the like. I know the basic principals but would like to be better educated. All I can find is discussions among people who are already in the know and I would like to fill in the missing information. I have looked at the Firefox website and they don't really simplify things either. I have purchased 32 gauge nichrome wire and would like to make my own igniters that are bullet proof as well as E-matches for dual deploy (my newest endeavor). Any advice or websites/discussions would be greatly appreciated.

Ematches? Buy the commercial solutions that don't require an LEUP (not the kits!!). I don't trust the blanks that are sold out there. I believe the "good" blanks go to the pyro industry. You can google information about Ematches and mixtures and go so far as to solder your own blanks. Use 40ga, nichrome wire. The problem is acquiring a shear to cut the double sided PC board and not run solder out to the end of where the bridgewire goes from one side of the board to the other.
Another thing, is one needs a decent ohm meter to measure the resultant resistance. It's nice to see a reading between 1-2 ohms. 6 to 10? Don't even consider using it. Sometimes a fresh batch of homemade ematches fail to fire even with good continuity. Let 'em sit for a few months and one then sees 100% reliability! Go figure. Trust me, don't bother trying to make ematches unless you want to spend several winters perfecting your technique:surprised:It's not worth the effort or risking a rocket. Now if we were forced due to regulatory issues I would be singing a different tune but it is not necessary anymore. Plus the ematch reagents can be plenty dangerous if one mixes them and expects to store them in a mixed state. Don't do it!!!. Could end up twisting a lid off and kaboom!!!. :shock:
You know the pyro guys use matches to set off shells and fireworks. If one fails, that particular effect is lost. If it fails in a rocket without backup, it's a tough deal.
Now igniters are a different story and you can google a ton of info on them. I believe the risk is manageable there and the commercial dips are very good. You don't have to do a lot of research if you don't want to. Kurt

++++ what Ksaves2 says. Listen to him. What he is saying exactly mirrors my experiences. Make your own igniters, but buy matches.

I've been making my own igniters for several years. I've got an potassium nitrate based formula made from items I got from Walmart. It includes magnesium shavings and has started motors from F though M. It is much harder to make igniters for the small motors then the large ones just because you have to be able to get the head of the igniter in the small nozzles. I use 34 ga nichrome wire for all my ingiters.

I have both digital multimeter and an old analog multimeter. I much prefer the old analog meter for measuring igniters and ematches. I usually have to teach people how to use it at the site when they ask to borrow it, but it really does work better IMHO.

If you are testing an ematch, 1 - 2 ohms is a good range. 0.5 - 1.5 may be better. Don't use anything above 2 ohms unless you've tested them on your electronics before. I've made some matches using 34 ga nichrome wire and wrapped it so the bridge is only 1/16" long and coating it with finely ground BP soaked in nitrocellulose lacquer. Those work with my HiAlt45 and Stratologger, but were only about 50% reliable on some other brands of altimeters. I've never flown them. Commercial match heads only work with commercial dips. Even then, I've never gotten a batch to be reliable enough to trust in flight.

Thank you for the information. What about the kit from electric match
https://electricmatch.com/products/see/8/nichrome-e-match-kit
Would that be a worthwhile product. It appears that they just need to be dipped.
Just curious.

If I were to consider a kit, that is one I would consider.

If you do, read the instructions. Then read them again. Follow the instructions and do not deviate from either the left or the right.

It doesn't hurt to read related information from reliable sources.

Greg

Any opinions on this:

https://www.amazon.com/dp/B00J4C0028/?tag=skimlinks_replacement-20

jpoehlman said:

Any opinions on this:

https://www.amazon.com/dp/B00J4C0028/?tag=skimlinks_replacement-20

Click to expand...

They work. Very reliable.

I have a thread in the recovery section. It is called " DD ematches" and I asked for opinions about them. I will be ordering some soon to try out.

https://electricmatch.com/products/see/6/mjg-firewire-initiator are commercial unregulated e-matches from MJG for less than $1 each. Why waste you time and risk you rocket while learning to make them reliably.

Bob

+2 on what Bob says.

It is not hard to make reliable igniters. If they do fail, you walk out to the pad and put another in the motor.

Making your own e-matches is a whole different issue. They are much harder to make reliably and if they fail, your recovery fails and damage to at least the rocket is almost assured.

I've been making my own igniters for years. I quickly gave up on e-matches. I tried several different methods and got to the point I was basically assembling commercial parts. Even that couldn't match the reliability of commercial matches.

Using redundant xmas bulbs in a paper tube was the most reliable method of setting off deployment charges I could come up with. I gave those up because the time needed to build those was just too much.