New Igniter

D13 reloads for my 18/20 caseing have become very difficult to locate. I manage to find some once in a while, but the quality varry. Right now the batch of loads I have are older, and some look like to be humiditized. So igniting these already difficult to start motors. Magnelites are up for the task, but their default 26 gauge wire is still to thick to fit through the tiny nozzle openings. Firestar mades some really thin igniter leads that I used to buy and dip with magnelite. Those worked well. But if I heard correctly, Firestar nolonger exists, and I can't find anymore of those wires. I tried some of those "Firefly" igniters, but it took the who pack just to get two motors going. I tried dipping them in magnelite, but the thinner ruined them. So... time to make my own.

I got some thin wire (about .5 mm), and some nichrome (Free from Stanford Systems) and did some experiments. I made a couple with just twisted nichrome, and then made some with soldered nichrome. The Soldered tested at 1 - 1.5 ohm, while the twist on tested at 1.5 - 3 ohms. I then dipped the igniters in MAGNELITE pyrogen. I test fired most of the igniters with a 9 vt battery, and they all worked great.

Here is a picture of an igniter.

Finally, I test fired one of the D13's mentioned above with my iginiter.
Here is a Vid.

nice man. nothing beats that pyrogen, nothing. I need to get some and some wires too. Does anyone know a good place to buy Nychrome. I think I could find the 26 gauge wire easily and put them together then dip.

but I feel the nychrome may be a problem.

What did you guys do?

Originally posted by Ryan S.
Does anyone know a good place to buy Nychrome.

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Hi Ryan,

Funny you should ask. We just had a lengthy discussion about this on the MicroMaxRockets Yahoo group.

The strongest vendor recommendation came from our own Micromister. And I quote:

McMaster-Carr Supply Company
473 Ridge Road
Dayton, NJ 08810-0317
732-329-3200
fax 732-329-3772
www.mcmaster.com

These folks have a vast selection of Nickel Chromium (NiChrome)
resistance wire. Years of expetimentation has proved the
best "general purpose" gage wire for igniters is 30ga .100"dia
6.75ohms 3208 feet/lb.
McMaster part no. 8880K27 will get you a 1/4lb spool approx. 802 feet
for about 23.80 plus ups shipping.
These guys are REALLY good, I've placed an order with them and had
the material in hand 2 days later.

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Another point in the discussion was the ease/difficulty of soldering nichrome wire. The easiest way is to use plumber's flux and silver-based solder. One member tried a solder that was 95.6% tin, 4% copper, and .4% silver (Silvabrite 100) and the joint was easy and strong.

Hope this helps,

Will Scarvie

I had great success w/ the old Estes (pre-Solar) igniters. They were just a length of nichrome w/ a realtively flexible pyrogen coating for about a centimeter.... Anybody try making one like that?

FWIW,
-bill

Very nice Doug:
I hear alot about the Magnelite pyrogen but haven't used it, Do you know what's in it?
I've used Firestars and igniterman pyrogens for awhile. But still perfer my own ApCP mixture on bare 30ga nichrome for cluster ignitions. They are about 2ohm at 3" long, a bit slower burn then other types which I think gives all the motors a chance to fire up before first motion. They tested at about 1/2ns.. they're pretty hot igniters yours look like they are really good as well.

Doug came over yesterday and we made a couple of these igniters. Man they were nice. They went together pretty quickly and were easile done. Touched them to a 9v battery and had a nice flame and lots of sparks.

Nice igniter!!

OK, so If I want to make my own igniters.... where do I get this pyrogen? Can I build these in my house/basement without causing a divorce from fumes, etc?

Astronboy:
Absolutely! there are any number of "pyrogen" mixtures you can buy as kits. Some are more touchy than others but all are mostly low oder things, Pratt Hobbies carries Igniterman, I think you can still by Firestars direct for Firestars, and Doug is using a mixuture I've hear of but never used. All have there go and bad points. but most will do the job
We've discussed this subject a few times in different spots in the forums, different wire gages and nichrome gage and ohm resistance requirements. I'm sure a search of the files will land you a ton of additional info. We have even had a lengthy discussion on the nichrome soldering question in the MicroMaxxRockets yahoo group as we are still in the hunt for an igniter for Micro clusters. Making up the wires, with or without soldered bridge nichorme is a pain, but the dipping can be a social activity at a meeting or "building session" or while sitting around sipping Adult beverages and shooting the breeze