What Ematches do you use ?? ?

What ematches do *you* use and in which configurations do you use them? With the limited availability of commercial ematches and the BATFE regulations, it would be good to see what you actually use. I've personally tried the skylighter ematch dip kit, but reliability is quite low. I've been trying to get some Oxrals, but no one seems to carry them anymore, and those that do, don't have them in stock.

Thanks

I have not yet flown any, but I have some of Quickburst's "Hotcoils", which can be ordered online and are regulation-free. They require more current than normal ematches, and he notes that they are mainly for use with the Perfectflite HA-45 (of which I have two, IIRC). That altimeter is advertised as putting out 5A@1 sec.

I notice that the beta instruction sheets for the new Missileworks RRC Mini reports an output of 5A@1 sec as well. I strongly suspect that he intends that altimeter to work with the Hotcoils as well. The old RRC2 instructions report only 1.25A@1 sec output.

I actually have been using some M-tek's that I got from a friend getting out of the hobby. I have about 18 left. Once those run out I am going to use estes ignitors I think. I have a high amp output circuit I found that will basically dump a whole battery for .5s. hook it to my altimeters output and I am ready to go. Tested it and it works. never flight testd it yet.

Ben

I'll be testing my first DD setup this weekend. I got the Newton's Third "Hot Wire" cannisters, as they work with my altimeter, a MAWD, and, of course, they're LEUP-free! https://www.rocketryplanet.com/auctions/Ejection-Canisters-(SMALL),itemname,350,id,auctiondetails

If they work as promised, I'll stick with them...and honestly, I can't see any advantage that the Hot Coils would have on these. The capped, plastic containers looks sweet, and they have 'lil foam plugs to put inside & hold the powder in contact w/the wire. IMO, this is much more 'elegant' & a lot easier than the HotCoils, where you hafta load the powder, add a filler like dog barf, then tape the end shut....not to mention the fact that they work with almost every altimeter & timer on the market not just one or two!

I'll letcha know how it goes! I'm shooting for my first DD launch on Aug. 11.

None of the above. I use Xmas tree bulbs for dual deploy.
https://s45.photobucket.com/albums/f77/BAR0051/?action=view&current=DualXmastreebulbs.jpg

I've used Quickburst's ematches. But due to his inability to currently ship these, I picked up a box of Davey Fires for a bargain from a dealer getting out of the business.

Both have worked flawlessly with my Adept altimeter.

BAR0051 said:

None of the above. I use Xmas tree bulbs for dual deploy.
https://s45.photobucket.com/albums/f77/BAR0051/?action=view&current=DualXmastreebulbs.jpg

Click to expand...

When you break the bulbs, do you pull the small wire wrapped around the filament posts out too?

That's what I've been doing. I don't want to get any false continuity checks or risk not firing the filament. The problem is that you have to break the bulb pretty far down to get to it and that usually leaves the filament standing pretty high above the glass and exposed.

Have you had any problems with the filaments breaking during flight?

No, I do not remove the small wire strap. I check the resistance and if it is not in the range I expect to see, I toss the bulb. Notice I use 2 bulbs so if 1 fails, I have a backup. So far I have had no problems using this method. Another member of the club has successfully used a single bulb glued into the end of a section of the tube the First Fire ingiters come in. He uses this in smaller (BT80 size) rockets. We both use Perfectflite MAWD alts.

BAR0051 said:

None of the above. I use Xmas tree bulbs for dual deploy.
https://s45.photobucket.com/albums/f77/BAR0051/?action=view&current=DualXmastreebulbs.jpg

Click to expand...

How many times have you implemented this technique, and what are your success rates?

Johnnie

The M-Tech ematches look promising. I'm going to go ahead and buy a box of 80 of them. They have a firing current of 0.750 to 1.000A, so thats within the limits of my altimeter.

We bought a bunch of quickburst igniters back before they got raided, and have been slowly burning through them. Once they are gone, it will be on to home dipped (using firefox'es ELV pyrogen) and triple redundancy (altimeter/acceleremeter, timer, and remote fire ove a rf link).

Johnnie said:

How many times have you implemented this technique, and what are your success rates?

Johnnie

Click to expand...

Not counting the ground tests, I have used them in 3 flights (I161, I211 & J350) for a total of 6 charges with 100% success.

Been using M-tecs for over a year now 50+ without a failure. I love'm.

I've been using J-Teks without a problem. They're slower than M-Teks but will not light a motor on their own.

Rocketjunkie said:

I've been using J-Teks without a problem. They're slower than M-Teks but will not light a motor on their own.

Click to expand...

I actually spoke to the guy at MTEK and he told me they were going to discontinue the J-Teks and only sell the M-Teks.

Deandome said:

I'll be testing my first DD setup this weekend. I got the Newton's Third "Hot Wire" cannisters, as they work with my altimeter, a MAWD, and, of course, they're LEUP-free! https://www.rocketryplanet.com/auctions/Ejection-Canisters-(SMALL),itemname,350,id,auctiondetails

If they work as promised, I'll stick with them...and honestly, I can't see any advantage that the Hot Coils would have on these. The capped, plastic containers looks sweet, and they have 'lil foam plugs to put inside & hold the powder in contact w/the wire. IMO, this is much more 'elegant' & a lot easier than the HotCoils, where you hafta load the powder, add a filler like dog barf, then tape the end shut....not to mention the fact that they work with almost every altimeter & timer on the market not just one or two!

I'll letcha know how it goes! I'm shooting for my first DD launch on Aug. 11.

Click to expand...

You might want to try the e-match kit. These work with all known avionics.

Deandome said:

I'll be testing my first DD setup this weekend. I got the Newton's Third "Hot Wire" cannisters, as they work with my altimeter, a MAWD, and, of course, they're LEUP-free! https://www.rocketryplanet.com/auctions/Ejection-Canisters-(SMALL),itemname,350,id,auctiondetails

If they work as promised, I'll stick with them...and honestly, I can't see any advantage that the Hot Coils would have on these. The capped, plastic containers looks sweet, and they have 'lil foam plugs to put inside & hold the powder in contact w/the wire. IMO, this is much more 'elegant' & a lot easier than the HotCoils, where you hafta load the powder, add a filler like dog barf, then tape the end shut....not to mention the fact that they work with almost every altimeter & timer on the market not just one or two!

I'll letcha know how it goes! I'm shooting for my first DD launch on Aug. 11.

Click to expand...

I have some of those. I haven't done extensive testing, but in one test one of the solder joints inside failed because I had to force the yellow foam in (it got stuck). They can be fragile, so be careful with them.

Deandome said:

I'll be testing my first DD setup this weekend. I got the Newton's Third "Hot Wire" cannisters, as they work with my altimeter, a MAWD, and, of course, they're LEUP-free! https://www.rocketryplanet.com/auctions/Ejection-Canisters-(SMALL),itemname,350,id,auctiondetails

If they work as promised, I'll stick with them...and honestly, I can't see any advantage that the Hot Coils would have on these. The capped, plastic containers looks sweet, and they have 'lil foam plugs to put inside & hold the powder in contact w/the wire. IMO, this is much more 'elegant' & a lot easier than the HotCoils, where you hafta load the powder, add a filler like dog barf, then tape the end shut....not to mention the fact that they work with almost every altimeter & timer on the market not just one or two!

I'll letcha know how it goes! I'm shooting for my first DD launch on Aug. 11.

Click to expand...

I've used the newtons 3rd canisters on 8 flights now. 100% success up to this point.

I was one of the beta testers for the Newtons 3rd hot wire, specifically with the ARTS. I bought a bunch of the original versions and found that they did not work with the ARTS. I offered to test the new ones and did a bunch of ground and flight testing. I ground tested about 10 canisters (both large and small) and flight tested 5 canisters. All of them were successful with the ARTS. I've never had any problems with them.

I would definitely recommend them. It's a good product. Good luck with your flight!

m85476585 said:

I have some of those. I haven't done extensive testing, but in one test one of the solder joints inside failed because I had to force the yellow foam in (it got stuck). They can be fragile, so be careful with them.

Click to expand...

I have to agree about the fragility. The failure mode I have seen is with the large canisters and the tail end where the wires exit. If the tail end gets pushed as the rocket is packed it can fail. I had intermittent continuity that only happened when the rocket was fully loaded. The problem was detected by the altimeter when I hoisted the rocket into position vertically - and went way each time I lowered it horizontal. I thought it was a problem in my wiring and worked on that assumption until I bumped the canister while testing it and realized that continuity was not consistent.

So far only one has been damaged this way - and I'm certain the damage was post installation during the final prep and loading of the chutes and nomex. All of the flights using these (small and large) on my Missile Works RRC2X have been successful. This failure as indicated was ground detected but could have been missed if the short had been present only in another orientation or during thrust.

eastvolt said:

I actually spoke to the guy at MTEK and he told me they were going to discontinue the J-Teks and only sell the M-Teks.

Click to expand...

Jeff told me just the opposite today, that 90% of their business is J-teks and they are going to discontinue the M-teks.

jderimig said:

Jeff told me just the opposite today, that 90% of their business is J-teks and they are going to discontinue the M-teks.

Click to expand...

Sorry, thats what i meant.

Crazyrocket said:

I offered to test the new ones and did a bunch of ground and flight testing. I ground tested about 10 canisters (both large and small) and flight tested 5 canisters. All of them were successful with the ARTS. I've never had any problems with them.

Click to expand...

ARTS 1 or 2?

Single or multiple battery configuration?

Where do I get MTEK matches?

n3tjm said:

Where do I get MTEK matches?

Click to expand...

If you have a LEUP, you can order them direct: https://electricmatch.com/product.html I did, no problems.

n3tjm said:

Where do I get MTEK matches?

Click to expand...

Or find someone who got some from the manufacturer, they probably do not need 80 of em (min order qty).

(Of course you must burn em at the field to stay legal....)

Snowman - The testing I did was with the ARTS 1 which is only a single battery configuration. They all worked flawlessly. In fact, during flight testing, I bent the wire right at the end of the canister (the large version) so that I could insert it into the small PVC pipe I use to hold BP charges. The wire came out the top of the PVC canister where it was securely taped to prevent the canister from moving. Hope this helps.

I've had good luck with the Newton's 3rd Hot Wire ejection canisters. I really like that the canisters are marked (in grams). This makes it easy for me to get the same charge every time. I've probably flown these around a dozen times. More info at: https://www.newtons3rdrocketry.com/

Before that, I used the old QuickBurst e-match-based canisters. They were great but are no longer readily available. Also the canisters weren't marked which made it a little harder to load the same charge every time.

And before that, I made my own using Christmas tree lights and the instructions on PerfectFlite.com. However, they were more fragile and took some significant time to make. After switching to pre-made ejection canisters I haven't looked back.

Jim

The testing I did was with the ARTS 1

Click to expand...

The ARTS 1 and 2 are different. The ARTS 2 has a current limiter to prevent brownout of the CPU. It won't reliably fire everything in the single battery mode. For example, when used with J-Tek ematches it should be used in the two battery configuration.

Handeman said:

When you break the bulbs, do you pull the small wire wrapped around the filament posts out too?

That's what I've been doing. I don't want to get any false continuity checks or risk not firing the filament. The problem is that you have to break the bulb pretty far down to get to it and that usually leaves the filament standing pretty high above the glass and exposed.

Have you had any problems with the filaments breaking during flight?

Click to expand...

I have also had great success with xmas tree bulbs. Four dual deployment flights using the xmas bulb for both apogee deployment and main deployment; one of these flights was my successful level 2. I do remove the shorting wire at the base of the bulb. I use a long precision tweezer (Griot's Garage) to grab the wire and carefully unwrap it. In my experience the filaments are amazingly sturdy. Carefully packed with black powder and wadding, I do not worry about them shifting enough to break.

I like the idea of using two bulbs for redundancy. This makes great sense as the altimeter should have more than enough current to light up both filaments. Thanks -