Any predictions on how this 3 stage rocket will perform?

Have you tested it for stability?

The top stage is an Estes Wizard, and the lower stages were made from another Wizard kit. You can see a fourth stage sitting alone that was made from the die cut fins from the kit. There's a lot of balsa on the stages I made, and I'm pretty confident the upper two stages will fly fine, but I'm a little worried about flying three stages.

I added a launch lug near the fins on the top stage to compensate for the c/g change. I was wondering if I should lengthen the body tube to make the rocket a little longer.

In any event, I'm launching it as a two stager later this week, but I was curious if anyone wanted to make book on whether or not it would be stable as a 3-stager...

I kinda patterened the lower stages after the Apogee.

Anyone would just be guessing. How much does it weigh, where is the cg at each stage, what motors are you using?

Tom

On Wed, 10 Aug 2011 08:52:41 -0500, "Steven P. McNicoll" puked:

>

I will this afternoon, weather permitting.

-- lab~rat >:-) Do you want polite or do you want sincere?

On Wed, 10 Aug 2011 10:45:46 -0400, "Tom Biasi" puked:

Jeez, you're trying to take all the guesswork out of rocket science.

In the 2 stage config, the c/g is on the first stage fins. With 3 stages it's at the top of the 2nd stage fins. Loaded it's 3.2 oz, 2 stage 2.5 oz, 1 stage is 1.4 oz.

For my first launch with 2 stages I'm going with a B6-0 and an A8-3 because I'm launching it in the hood and only have 5 acres to work with. Second launch will probably add another B6-0 and the same config otherwise for a 3 stage launch.

Does that make the guessing easier? I don't know.

-- lab~rat >:-) Do you want polite or do you want sincere?

On Wed, 10 Aug 2011 10:45:46 -0400, "Tom Biasi" puked:

Jeez, you're trying to take all the guesswork out of rocket science.

In the 2 stage config, the c/g is on the first stage fins. With 3 stages it's at the top of the 2nd stage fins. Loaded it's 3.2 oz, 2 stage 2.5 oz, 1 stage is 1.4 oz.

For my first launch with 2 stages I'm going with a B6-0 and an A8-3 because I'm launching it in the hood and only have 5 acres to work with. Second launch will probably add another B6-0 and the same config otherwise for a 3 stage launch.

Does that make the guessing easier? I don't know.

OK I'll guess, with a little help from my crystal balls. The rocket will lift off wobbly and be on its way down when the second stage fires. The third stage will fire on the ground.

Tom

On Thu, 11 Aug 2011 09:07:44 -0400, "Tom Biasi" puked:

Well that sounds exciting. Why do you say that? How about a two stage launch? Like I said, if weather's good, I'm doing one of those this afternoon.

I have a hunch that the three stage configuration might be a little like you said because of the bulk of the fins. I don't have a lot of experience with multiple stage rockets, but for some reason I think this one might benefit from a longer third stage body tube. If that's the case I'll build one and meanwhile, the spectators can hide behind the car...

-- lab~rat >:-) Do you want polite or do you want sincere?

Ok, last night I took it out and flew it. We launched my Red Max first with an A8-3 and that was a predictable low altitude launch that flew perfectly.

Then I launched a two stage Comanche 3 with B6-0/B6-4 combo and it flew well but landed in some guy's back yard. Fortunately my friend's kid was there to hop the fence and get it.

Then it was time for the two stage Wizard. I used a B6-0/A8-3 load and it flew perfectly. Observations, it dropped the first stage surprisingly low, about 350 feet. The second stage went out of sight. If it weren't for the kids, it would have been easily lost. As a result it was difficultly lost.

I guess the tree line made high altitude winds hard to detect, and as soon as it got over the Australian pines, it was blown off to who knows where. Fortunately I have a box of those rockets and they only take a coulple of hours to build. That was the second one I lost, the first was flown as designed with a C6-7. Not a good plan if you like getting your rockets back...

Did you have fun? I didn't mean to discourage you, you pushed for a prediction and mine was based on what usually happens to me when I plan as little as you did. Happy flying.

Tom

On Fri, 12 Aug 2011 20:06:34 -0400, snipped-for-privacy@optonline.net puked:

I planned, I just didn't do the math ;)

I think we're gonna need a bigger field for the next launch...

-- lab~rat >:-) Do you want polite or do you want sincere?