E-Match Question

Why won't anyone respond? I realize that I'm not a regular poster, but I do frequently visit the group. There can be good info. found here at times (as long as you can read between everything else). Please?

Didn't see your post until now, odd ;/

Well, I'm still working on my last box of Daveyfire 28B's so I'm pretty set. That being said I used to use flash bulbs but those are VERY hard to come by now-a-days.

Once my supply of 28B's are gone I'm going to give xmas bulbs a shot. $1.99 gets you a whole string of them at Target. That's about the price for one ematch, total bargain.

Ted Novak TRA#5512 IEAS#75

Do you take the glass of Xmas bulbs - or how do you get enough heat?

H

The way I've seen it done is to crush the tip of the bulb exposing the insides, hot glue bulb in a crdbrd tube and fill with BP. I'm sure google could come up with some sites.

Ted Novak TRA#5512 IEAS#75

I used this method once for dual deploy and it worked 50%. I had continuity on the altimeter when the rocket launched, but during flight, the bulb in the drogue section wound up coming loose and didn't fire. The bulb with the main deployed perfectly though.

I haven't taken the time to really think of other ways to make this work, but I am sure there are many ways to do so. Plus they are SUPER cheap, so if you figure out a reliable way to use them, then great!

Hey Ted, hope your rockets aren't worth much more than that because I've seen a lot of Xmas bulbs not work.

Phil

Little bit of self promotion here but take a look at Newtons3rdrocketry.com and select products. We have a ejection solution based on 48 gauge Nichrome bridge wire on a PCB substrate. Much like an ematch without the pyrogen. Come in a prepackaged ecan with either a 2 or 5 gram capacity. Very robust and the small ones are ~ $1.00

Before I even think of using xmas bulbs on flights there WILL be some serious ground testing. If that fails then it's no to xmas bulbs.

I haven't worked out all the details yet but small glow plugs could have some promise.

Ted Novak TRA#5512 IEAS#75

Flashbulbs are still readily available at

Bill Cress is a very friendly, easy to work with kind of guy.

Have these been tested using a PerfectFlite MAWD set up for dual deployment?

Once I run out of Oxrals, I was going to try some of Quickburst's Cosmos matches. Lookee here

Joe Michel

Joe- I've used most all of Quickburst's offerings, from igniters to ematches. Thusfar I've nothing but praise. The quality and the service is first-rate. David even accepts Paypal.

Kevin

Ground testing isn't really gonna help with Christmas Bulbs because ground testing isn't representative of flight contitions. The filament on the christmas bulb is pretty weak and not soldered on, so that is one place where the stress of flight can cause a failure. Another is the bulb coming un-seated. Ground testing, while smart if you are trying to figure out how much BP to use, isn't going to be able to account for those things. And the one I used on my 3" Thor failed on an I211. I imagine it would have failed on a J350 or 570 as well.

Your best bet is to test the charges in flight as a backup to whatever e-matches you have installed. Really, you just want to make sure that you get them to fire with a high rate of success, so maybe stick 1/2 gram or 1 gram of powder in them or something.

the notorious t-e-d wrote:

I've used Christmas bulbs with great success. The key is to use more than one for each ejection charge. I normally use 2 bulbs per charge for redundancy, but based on the canister size, one could use 3 or 4. It's not much more work to add more if desired. It's much less work and costly than replacing a rocket.

I also use ematches, and I always use at least 2 for each charge for the same reason.

Kevin

Nice seein' ya again Darrell!

Actually I just got lucky and found a bunch at a local kick butt surplus store. Axman = mecca for rocket and robot stuff. Even picked up some nice 4" crdbrd tubes.

Ted Novak TRA#5512 IEAS#75

What size flashbulbs do you typically use? It's been years since I've used any, and I don't remember the size designations (last time I used them was in the early seventies along with some Centuri Sure-Shot igniters -- this was my cluster ignition method of preference...)

David Erbas-White

Darrell D. Mobley wrote:

Yes they have using a duracell 9V

Nice to BE back. ;-)

Surplus stores are the bomb. Whoops! Did I just say that? Run! It's the ATF!