first time At F21-4W

[stevem]

This weekend was my first time launchin AT single use F21-4W. This is the largest motor I have ever used.
All I can say is WOW! The first time out the copperhead ignitor burned up without lighting the engine. (why doesn't AT include and extra ignitor in the package?!)

We replaced the igniter and loaded it back into my Estes V2.
The rocket almost disappeared. The roar and the smoke were awesome! Chute deployed right after apogee and the rocket took a liesurely drift right into the top of one of my cotton wood trees! My wife lifted me up in the loader on my tractor and then I used a 20' pole to knock it out of the tree. Only damage was a broken shock cord.

Undaunted we loaded an F21-4W into my scratchbuilt GBU-15 (possibly the ugliest rocket ever built). A PERFECT flight in every sense! The really cool thing was the motor kind of spat and sputtered for a couple seconds before it finally took off with a roar! Rocket landed about 200' from the pad! COOL!!

Third time we put up my 42" long Coyote on the F21-4W and it was by far the best flight this rocket has ever seen.

I love these motors!!! but i am not thrilled with the copperhead igniters - are there any alternatives?

 

[swimmer]

I also had the opportunity to fly the F21-6 again yesterday and along with steven they are awesome.

When I flew the F21 no one wanted to go back to black powder. They all were real surprised by the power, sound, smoke and fire of these motors.

I also flew the redesigned Aerotech F20 in my Mustang. I have always thought the E18 was the perfect motor for the Mustang but the new F20 makes the Mustang smoke off the pad and the altitude is, well, breathtaking.

We finally got to "fly at the farm" yesterday. Lots and lots of open space, endless blue sky, nice soft green wheat and a beautiful 69 degree no wind day. Flew all these several times each: mini-Armageddon, Mustang, mini-"nuthin special", ACME Spitfire, Deuces Wild and Blue Ninja. Never walked more than 50 yards to retreive any. What a day!!

 

[Zippy]

There are lots of alternatives to the CrapperHead ignitor. AeroTech themselves have the FirstFire And FirstFire Jr.'s. Both are two wire with lot's more pyrogen but their not what I would consider cheap. I keep a couple of extra FirstFire's with me but use the CrapperHeads that come with the motors and save the better ones untill needed. I'm sure some other people will chime in with their favorite ignitor brands. You can even make your own with nichrome wire and dip wich is what I'll be doing as soon as I run out of what I have.

 

[Stones]

Try not to over bend the "crapperheads", if you can help it. I usually just put an "s" bend in them and put them in the motor with no tape or rubberband to hold them in. I've seen some copperheads with very little pyrogen on them and I'm guessing the one that "burned up without lighting the engine" may have been one of these or the was a bit of oxidation on the motor grain. All in all, I've had perty good luck with the AT igniters, though I know they are not as good as they could be.

 

[Beanboy]

I'm 100% so far with Copperheads with about 30 or so motors. I make sure their is good conact with the grain, put a big loop in it before securing it with the rubber band. I then press the loop down a bit to make sure good contact remains. Not much space left for clips, but they don't need much anyway.

Wow, just typing that out has me excited for the first launch of the year in a couple of weeks. First flight always seems a little more exciting...

-B

 

[loopy]

I'm not quite 100% with Copperheads, but I'm pretty close. Just make sure the head is all the way at the top of the grain, bend it over to the side a little (but do not crimp it, that will ruin it), tape it down, and punch a hole in the tape to vent it, and you should be fine!

Loopy

 

[astrowolf67]

Umm, what Loopy said. I do that, plus use the AT Copperhead clip. My success rate with copperheads, is better than with Estes ignitors.

Copperhead tips,
1. DO NOT bend them sharply.
2. Slightly angle the tip so it will touch the propellant.
3. Before inserting the igniter into the motor, run your fingers along the edges to remove any slivers of copper that might be there.
4. I don't use the rubberband, or plastic cap (RMS). I tape it in with a piece of masking tape, and poke a vent hole in the tape.
5. If possible, use the copperhead clip. If not, use tape to insulate one jaw of each clip, and install them with the tape on opposite sides of the ignitor. Try to avoid using clips with teeth, they can bite through the tape and igniter. If your clips have teeth, use electrical tape instead of masking tape.
6. Make sure your launch controller is pumping plenty of juice to the igniter. In some cases, a strong battery can burn through any shorts on the edges of the copper foil, and still light it up.

 

[loopy]

Originally posted by astrowolf67
I do that, plus use the AT Copperhead clip.

If you don't have the AT clip, just put a few wraps of masking tape on one side of each alligator clip then hook it up with the masking tape on opposite sides of the ignitor. Kind of simulates the AT clip.

Loopy