1) I figure I need to install some kind of switch for the altimeter. Any suggestions for good sources for a small, durable switch?
2) Where the heck do I get ematches, or whatever you call the charges that the alti will fire to eject the drogue and main?
3) Any other hints, tips, etc, for how to make dual deploy work on your first try? I'd really hate to loose this bird and the electronics on my first L2 flight (not to mention not qualifying!).

Greg, this is just one opinion...
1) It can be a very durable key switch (I only use a specific brand that I have NEVER had a problem with... yet), a great switch that Jim Amos sells ( http://www.missileworks.com/index.php?main_page=index&cPath=2&zenid=hmp963s9mf1dqpsiisj4g9rjc5 ), or as simple as just two wires that you stick out of the vent port and twist "closed" very quickly and very carefully (if you turn the altimeter on and off quickly, it can ignite your charges), then stuff them back in through the port. I've never tried this, and it's usually done for MD altitude flights.
2) Tim Thomas brings them to the launch.
3) ground test!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!! to make sure things separate and your chute comes out... can't stress this point enough.

Good luck!

Greg,

Just my thoughts ...

1) I second the screw switch recommendation. Adrian actually has some good ones as well ( http://www.featherweightaltimeters.com/).
2) I've become partial to the Quest Q2G2 igniters, they're very low current, and perfect for setting off bp charges. Probably don't want to use them for motors though. They're pretty cheap too, next to making your own they're the cheapest I've seen, though I don't know what Tim has on that front.
3) Another second on ground testing. You might want to test the altimeter too. I just hook up a couple small light bulbs in place of igniters, and use a straw on the barometer, tho there are other ways to test. I actually had some documentation issues with one (dd and apogee settings were switched), plus it's good to know that the altimeter works as planned before hand. Oh, and a fresh, new, never used battery 🙂

Adrian's screw switches are great. I use them almost exclusively. As for the ejection charge I'd use a setup such as this:

http://tinyurl.com/mq9amx

Edward

so where can i get black powder?

I have always used Missile Works Rotary Switch.
http://www.missileworks.com/index.php?main_page=index&cPath=2

For ejecton charge, I still use xmas bulbs. Kind of hard to make
but have never had one fail. Cheep to.

I'm just learning ejection charges for my L2 also, and it has been frustrating to say the least. I must have fired 12 charges total, of 4 different configurations. I haven't tried the glove tip method (seems like it would work good for large charges), but I have given up on the Christmas tree bulb and simply packing in a cardboard launch lug. Neither produced enough compaction, and the J-tek match would sometimes bust open the container before the powder burned. Burned a couple of chutes trying to get it right.

Using the little plastic medical vials has been the best solution for me for 0.5- 1.5 grams of 4F. A bit of cellulite packing peanut in the top maintains compression, and they are the fastest of any I've tried to make. I get more punch per gram with this method. I got them from Coast Rocketry.

PS. though some sources claim 1.6 grams per cubic centimeter of BP, I think 1.2 grams per cc is more realistic. You can effectively treat a cc as a gram and have a small margin of safety.

You should really try the surgical tubing method. It beats everything out there. Easy of setup, ease of use - no worry about compacting the powder, holding it in a container, making sure the e-match is in contact, worrying about the powder being secure during the flight. You can make some ahead of time and not worry about them in the range box coming apart.

Edward

unless I'm getting WAY up there, here is what I do for ejection charges:

1. Find some LOC 0.5" launch lug tubing. Cut this into various lengths from .075" to 1.50"

2. Get some 0.5" dowel and cut it into 1/16" or so lengths... Think of these as itty-bitty bulkheads 🙂 Drop one bulkhead into each of the aforementioned LOC launch lug sections (they will fit just right)

3. Lay down a piece of waxpaper. With the "bulkheads" down, put a few drops of epoxy into the top of each tube. Just enough will bleed through so you firmly affix the slab of dowel into the end of each tube

4. Go to Ace Hardware and and get some plastic table leg protectors. They come in a zillion sizes. These are the "feet" at the end of a table leg. The lugs above will fit into them perfectly. Affix those table leg ends to each end of your ebay.

5. Drill the canisters and the table leg ends with a hole big enough to pass an ematch.

FWIW, I don't "pack" the powder. I just pour it in, roll up a piece of paper towel for a plug, and tape it all in place. I've used some of these canisters dozens of times, from 29mm up through 7.5" airframes. The table leg protector holds the canisters in place perfectly - out of the way, pointed in the right direction, no wires to get entangled. It is a good idea to use modeler's clay or Sticky-Tack to plug the area around the hole.

I've used this method to 20K perhaps 100 times. I use surgical tubing when going higher. For the vast majority of flights, this is a very repeatable and durable method...

so where can i get black powder?

Greg, if I'm at the launch when you go for L2, I'll give you some. There's a thread on this elsewhere, try gun shops. I get mine at the Blunderbuss on Colfax in Denver.