# First Scratch Ignitors

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#### jerryb

##### Well-Known Member
Originally posted by Blue_Ninja_150
it is the CAT5 stuff, i asked to make sure it wasnt 5e.
if your gonna use "patch cord" or premade cables.. be wary of belkin cables... they use stranded wire..

I throw the solid stuff away in scrap pieces all the time... guess i should start keeping it and dumping it at auction somewhere eh??

Guess I'll bring a couple hunks to the next launch to see if any of the HPR guys want some... never actually thought about people needing it to make ignitors.

we're gonna be pulling out hundreds of feet of cat-5 at several locations.. replacing it with fiber optic cable...

later
jerryb

#### wwattles

##### Well-Known Member
Originally posted by jerryb
we're gonna be pulling out hundreds of feet of cat-5 at several locations.. replacing it with fiber optic cable...
You're lucky! We recently pulled out thousands of feet of fiber optic and replaced it with Cat-5. Gotta love military efficiency and contracting!

Personally, I've been using some 2-strand 24 AWG alarm wire that I picked up at Radio Shack for the larger igniters, and 34AWG wire-wrap from a local electronics store for the small stuff.

WW

#### BlueNinja

##### Well-Known Member
Where do you find a wire wrap tool? Everywhere I look (except for Radio Shack, where they didn't have any instock) the people get confused as heck when I ask for a wire wrap tool.

#### wwattles

##### Well-Known Member
Originally posted by Blue_Ninja_150
Where do you find a wire wrap tool? Everywhere I look (except for Radio Shack, where they didn't have any instock) the people get confused as heck when I ask for a wire wrap tool.
Try your local electronics supply store. If you don't know where one is, try the phone book or ask at the hardware store - they could probably tell you. That's how I found mine.

WW

#### BlueNinja

##### Well-Known Member
I tried 2 hardware stores and thaey gave me the same response-

Sorry, don't know what you're talking about.

I will try the electric supply store.

#### limd21

##### Well-Known Member
Man! It's got to be 15+ years since I've had a wire wrap tool in my hands, and even then I knew they were one of those things that was going to be a trivia question "what the heck is this thing?"

Anyway, if you don't have an electronICS supply house - not electricAL supply (two different things) - in your local area, Radio Shack's website has them:

https://www.radioshack.com/product.asp?catalog_name=CTLG&product_id=276-1570

#### Batman

##### Well-Known Member
FYI - The CAT 5e just means the wires are twisted, makes them faster for some reason. But there is CAT 5e cableing with solid wires, I'm holding some right now . I really think the CAT 5 is a great way to go. The pairs are already twisted together, just strip 'em and dip 'em. I made my first eight this weekend using the solderless technique with 36 guage nichrome. Tried the nail polish and I'm gonna use the ping pong ball dip on a few too and see which seems to work better.

Will the BP/nitrocellulose combo fire APCP reloads reliably without being dipped in pyrogen? My pyrogen is on the way too so I can test that out as well. Do I need to use a laquer sealer over the pyrogen?

#### limd21

##### Well-Known Member
Originally posted by Batman
[B I really think the CAT 5 is a great way to go. The pairs are already twisted together, just strip 'em and dip 'em. I made my first eight this weekend using the solderless technique with 36 guage nichrome. Tried the nail polish and I'm gonna use the ping pong ball dip on a few too and see which seems to work better.

Will the BP/nitrocellulose combo fire APCP reloads reliably without being dipped in pyrogen? [/B]
I'm a bit confused. How do you do "strip and dip" with nichrome? Shouldn't this be strip, wrap nichrome, dip? I thought "strip and dip" only really applies if you're using conductive primer.

As to not using pyrogen with APCP, I can't help there since I only fly BP. From what I've read, a pyrogen is needed because APCP is much harder to ignite than is plain BP.

#### Batman

##### Well-Known Member
Sorry, I should have been more specific. I was trying the solderless with nichrome this weekend. The "strip and dip" comment was simply to point out how the CAT 5e was already twisted and ready to go. Someone up above had made it sound like using anything other than shooter's wire was too much trouble. If you are using a conductive primer, which I am also trying, with the CAT 5e it is as simple as strip and dip. I am basically trying to make a handful of ignitors using every method I've come across to figure out which method is the best mix of reliability and ease of production. Again, sorry for the confusion.

#### rbeckey

##### Well-Known Member
My ignitors lit five for five G38 and G64 motors. I built them in as some were a little too thick to push in. Next time I'll thin the pyrogen a bit more. No huffing or puffing, just whoosh and away.

#### Stymye

##### Well-Known Member
can the solderless igniters be used with conductive primer ?

I made a bunch of solderless igniters and than realised I have some firefox conductive primer stashed away

#### SpartaChris

##### Well-Known Member
I have been using strands of steel wool instead of nichrome (since I couldn't find it until recently) and that has worked very well as I had no problems launching G-80's just a few weeks ago.

The wire wrapper tool helps enormously as the steel wool is pretty fragile.

-Chris

#### BlueNinja

##### Well-Known Member
I don't think it would, it kinda defeats the purpose of wrapping them with wire. You could if you wanted to, i think.

#### LampertRocketry

##### Well-Known Member
Originally posted by limd21
For others who've used both the nichrome bridgewire and conductive dip primer, is there a good reason to favor nichrome over the conductive primer?

I used to build my own with nichrome, but since I started using a conductive dip, I find it a lot more convenient. Strip, dip. That's all that's needed for a good black powder ignitor. For other motor types, it's strip, dip, dip.

Is one reason nichrome is to be favored is that its electrical current requirements are lower? I use a hefty battery (from my cordless drill), so I've never had any problems with enough amperage capacity.
There sure is a good reason. If one builds with nichrome wire, the current requirements will be considerably LESS than the conductive primer dipped igniters.

The article on Info Central is a really good suggestion for construction, but it leaves far too much nichrome exposed in my humbe opinion, increasing the resistance of the nichrome jumper and increasing the current requirements. What I do with mine is very similar, but I only leave perhaps 1/2" of nichrome exposed or 'unshorted' to conduct current (at most). This results in an igniter that will take much less current. I am still testing, but have not had a problem lighting the nichrome igniters with a 9 volt battery, whereas the dipped igniters don't always light with the 9 volt battery.

There was a question asked about storage. Baggies are fine, but I keep mine in a long fishing lure or small parts box to prevent mechanical stressing. It is the mechanical stressing that will cause failure over time. Make sure that they are not bent or crushed - that will lead to sure failure with the dipped units. The nichrome units are considerably more robust in this regard as well, but the pyrogen will fall off if stressed mechanically.

For nichrome, I went to eBay and purchased several small 50 - 100 foot rolls at about $3 per. Tried them all and they all work great. For wire, I went to eBay and purchased a few rolls of twisted pair. A thousand feet of #26 twisted pair for about$9. It will last me a lifetime. I also purchased some single conductor wire-wrap #28 wire and bought 5,000 feet in red and 5,000 feet in blue for about $20. Again a lifetime supply but I haven't tried twisting it or dipping it yet. WHY did I buy so much wire? Well, for one thing, I won't have to worry about going out looking for CAT5 (or better yet, 50 pair cable, which is discarded all the time) and dissecting it. I have a lifetime supply now.... and we will use it for all of our other wiring needs in future. Good luck with building your own igniters. If you are doing it to save money you are probably making a mistake. Unless you fly TONS of rockets or unless it is a club project. For the 20 or so igniters I use in a year it is cheaper to buy the **** things than to build them. We are building them for the fun of it and to prove to ourselves that we can master that aspect of the hobby. Murray Lampert #### Stymye ##### Well-Known Member I made my first batch today I used the cat5 ,4 pair cable($0.9 per foot)
it turned out to be the teflon coated type ,I dipped the ends in acetone for about 1 min before dipping and let dry
and the pyrogen stuck well
I did the nichrome twisted type posted earlier
they all ohmed out between 1.5-2.5ohms

I used the Firefox standard Pyrogen

SECSQUIB
Electric Igniter pyrogen - original blend $7.95 3oz/bottle https://www.firefox-fx.com/ignition.htm enough to make atleast 200 single dip (atleast!) I made 25 double dip and 30 single dip once dry, I dipped them in a thin ping pong mix I tested 5 and all went off right away with a brilliant burst (9v) and I lit 2 with an electron beam, they took about 1 sec heres a pic of a finished single and a double I'm think the small ones will fit the smallest aerotech motor #### Stymye ##### Well-Known Member I used the wire wrap tool from RS,,I got the part # from their website ,they had to dig around in the back room to find it It looks just like a jewlers screwdriver heres a batch of the small ones the one on top is a First fire jr for comparison #### Stymye ##### Well-Known Member I decided to try and catch the last one with my crap digital camera I set up a poster board and with the 9v in one hand and the camera in the other, .....I got lucky and got it full burst!!! I think the brighness overwelmed the camera a little but you get the picture (I wish I was this lucky with lift off shots.!) the only drawback to the firefox is that they state that it can't be reconstituded once mixed and only lasts a few days I wasted much more than I used but for the money invested I still came out way ahead.. thanks to the previous posters for all the good tips and info! #### rocketsonly ##### Well-Known Member WOW! Nice shot. I remember seeing a video some guy made online with home made igniters igniting, but I can't seem to find it again! Just shows how much of a pyro I am... #### Ryan S. ##### Well-Known Member acetone should dissolve it, if not you carefully crush it and mix it with acetone #### Stymye ##### Well-Known Member thanks ,I'll try that.and report back #### rbeckey ##### Well-Known Member I am looking for a source for 26 or 28 gauge wire. The Cat5 cable I used had 24 ga. twisted pairs, But I'd like to find smaller gauge wire. RS did not have it, nor did Lowes/Home Depot. #### kgholloway ##### Well-Known Member I'd try RS again and ask for 30 gauge wire wrap wire. You'll have to get two spools and twist the wire together using an electric drill. I use Cat5 cable to make ignitors for my 29mm and 38mm RMS motors and the 30 guage for the 18mm to 29mm "Hobby Line" reloads and single use motors. Both sizes work extremely well using the Ignitorman conductive primer and pyrogen. Ken Holloway #### rbeckey ##### Well-Known Member I went back to RS and asked for the 30 ga. wrap wire and it turns out they "keep it in the back" for whatever reason. I got red and white and will build some small ignitors. I am thinking that one of those soldering stands with a MAGNAFYING glass may be in order here. https://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&category=20761&item=4320944470&rd=1 I think I saw one of these in a Big Lots store the other day. #### LampertRocketry ##### Well-Known Member Originally posted by rbeckey I am looking for a source for 26 or 28 gauge wire. The Cat5 cable I used had 24 ga. twisted pairs, But I'd like to find smaller gauge wire. RS did not have it, nor did Lowes/Home Depot. Best place for that is on eBay. Keep looking. I picked up 2,000 feet of red and 2, 000 feet of blue 30ga. wirewrap for about$35. A lifetime supply I think. I also picked up 2,000 feet of 28ga twisted pair for about $10. The difference is that the wirewrap stuff is significantly smaller (thinner insulation). ML #### SpartaChris ##### Well-Known Member Does anyone know where to get paired, non twisted wire? Kind of like speaker wire, but with a single strand, not a mesh of it? -Chris #### BlueNinja ##### Well-Known Member Ive got maybe 100' of some stuff that looks like untwisted C5, don't know what it is though. Maybe you could just buy some cat5 and untwist it, unless you need twisted pair Blue #### LampertRocketry ##### Well-Known Member Originally posted by SpartaChris Does anyone know where to get paired, non twisted wire? Kind of like speaker wire, but with a single strand, not a mesh of it? -Chris Try finding some flat ribbon cables used in computers... there's plenty of surplus around. Just peel off 2 conductors and presto... two conductor UNtwisted. #### kgholloway ##### Well-Known Member From your description I believe what you want is called "shooting wire". Here is the description: ----------------------------------------------------------------------------------- Shooting Wire 2-wire, solid copper, 22 gauge. Yellow insulated. Red polarity stripe on one wire. Used for connecting electric matches to slats or to electrical firing systems. ----------------------------------------------------------------------------------- I believe that this is what is used in Aerotech's "First Fire" ignitors. It's listed as part number "GN5010" at$31.25 for a 500 foot roll on the Skylighter web site at:

https://www.skylighter.com

Ken Holloway

#### powderburner

##### Well-Known Member
They are re-wiring one of the rooms here in the engineering building and there are scrap lengths of blue-clad stuff marked 'Cat 6' laying all over. It has four twisted pairs of what looks like solid conductor, and looks like something readily usable for igniters. What do you guys think?