My Formula 200 pics!

Holy crap! What a beaut!

Flyfalcons said:

Holy crap! What a beaut!

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Thanks, man! It's a whole lot uglier the closer you get, but then so am I!

John,

Rocket looks great! We going to see any shots of the internals?

NateLowrie said:

John,

Rocket looks great! We going to see any shots of the internals?

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I suppose I could. I'll be outside with it all day tomorrow.

Final weight without motor = 56 lb.

CP = 91.6"

CG = 72.5" (actual)

Weight with motor = 67 lb.

Final stability cal. = 1.59

Ground tests commencing!

Going with 5cc in the booster and 6.5cc in the main. Back-ups will be 6cc and 7.5cc. I learned a lot today. The two unfortunate things are: 1) I only have 6cc wells, and the main back-up charge needs to be bigger. Will have to use PVC. 2) my D-bag method was a bust; two many tangles. Will use the "attach bag to the chute apex" method. But my chute doesn't have a way to attach it, so I have to get some paracord and make a loop.

All in all, I know what to do. And I have 12 days to get it done.

Nat asked for internal pics. Here are a few.

Inside nose cone.

Inside booster.

AV bay lid.

AV bay lid closer.

I'm a victim of wishful thinking. If your orange wires get "ratty" from multiple flights can you clip them, drill out the remains from the bulkhead and replace? Kurt

You bet. But considering I'll probably only launch this once a year, I expect them to last a long time. Just a bit of 5-min epoxy in the hole.

Bat-mite said:

You bet. But considering I'll probably only launch this once a year, I expect them to last a long time. Just a bit of 5-min epoxy in the hole.

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Put a piece o' duct tape over 'em and I bet they last longer!! Kurt

Good idea! Thanks.

Oh, I thought I would share a detail. Since the 6g charge wells are so wide, I used two e-matches in series in each one. I spread them out inside the well to get maximum ignition of the powder. Seems to have worked well.

If your bulkhead makes a 6 gm charge well look dinky;
you just might be a rocket redneck.

You don't need GPS on that thing - just a wide angle lens on your camera.

Not until I put a full N in it to 12,000 feet. :wink:

Bat-mite said:

Oh, I thought I would share a detail. Since the 6g charge wells are so wide, I used two e-matches in series in each one. I spread them out inside the well to get maximum ignition of the powder. Seems to have worked well.

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I would put them in parallel. In series, if one goes bad neither one will fire. In parallel if one is bad the other will fire. In series you double the chances of a failure.

And BTW, nice rocket! I need to build me something like that.

In parallel you double the resistance. I don't know if the altimeters can handle that.

The e-matches I use are the ones with the chip. Even if the chip is unable to superheat, you still have continuity through to the other match. I think series is the way to go.

Bat-mite said:

Not until I put a full N in it to 12,000 feet. :wink:

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I have an N1000 just sitting around ready to go whenever your ready to drag...

Bat-mite said:

In parallel you double the resistance.

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Wrong

Titan II said:

Wrong

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Correct

1/Rt= 1/R1 + 1/R2 + 1/R3......

I can't remember my Ohms law stuff. But in series I'm popping one match, then the other match, whereas in parallel, I'm popping both matches at the same time. I don't know how much current my RRC2+ can handle, but am I not doubling the current draw in parallel?

Yes, the current increases, but the resistance decreases.

Titan II said:

Yes, the current increases, but the resistance decreases.

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Okay, well, that's what I meant. They say not to pull e-matches in parallel or you can pull too much current through the altimeter.

oops wrong thread
Rex

Great flight today John!! Sorry we didn't get to say bye before we left. Here's one of you prepping

John,
Here are a couple more pictures of your flight.

Nice flight, I got to see it from the treeline while I was searching for my rocket.

It was a nice flight. I also think Mr John here is going to use a tracker next time he flies... even if "it's not going that high"....

Nice pics! Hope you post the details. Glad to hear you guys are getting flights in the air.

Nice rocket!

With the ematches I put a little bit of heatshrink tubing on the metal parts so they have no chance of shorting out on the charge canister. In your case it might help them not shorting out on each other too. I have never set a match off yet with the heatshrink gun

FWIW I would go parallel, unless the favoured failure mode for ematches is going shorted. I don't have any real data to look at.