I just found the RKT file that was posted to RMRR (link at the top of the review), and when I loaded the C6-7, it came up with a 0.59 margin using the RocSim calculations. This is not my file, but someone else's (possibly the author of the review...).

We have an unstable model here. If you try to fly it with no ballast, it's an incident waiting for the moment to happen. Estes did not test this design sufficiently before releasing it.

Shoulda tested with RocSim...

__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635

Ok, what do I need to do to be sure my model wont go all wacky and jam my girlfriend in the eye?

Ballast? In the nose cone? How much? Of what kind?

Thanks!

If you place (jam) about .5 ounce of modeling clay up into the nose it would most likely be plenty.

A fin area increase would probably be of benefit also.

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

Charlie,

Like ghrocketman said, about a half ounce (or even just a quarter ounce) of modeling clay would work, and would probably be the easiest to stuff into the nose cone, especially if you've already built the model and glued the end cap onto the nose cone. Use a wood dowel, or something like it, to pack the clay as far into the tip as you can.

If you haven't glued the two pieces together yet, you could even use two 1/8th ounce fishing sinkers held in place with epoxy, then glue the end cap onto the nose cone. Does the same thing.

Since you're following this thread, understand that this problem is design-related. Estes goofed on this one by not fully testing the design before shipping the kits. However, as you can also see, it's not impossible to fix the problem. One just has to understand the nature of the problem, and that comes with time and practice.

Charlie, do you have a copy of The Handbook Of Model Rocketry, Seventh Edition, by G. Harry Stine (and Bill Stine)? It's a great investment for someone getting started in model rocketry, because it explains what we've touched on in this thread. There is an art and a science to rockets. When you have a grasp of the science, the art develops from it. Give some thought to picking up a copy and reading it. You'll want to keep it handy as you will find yourself going back to it again and again for information.

__________________
Craig McGraw

BARCLONE Rocketry -- http://barclone.rocketshoppe.com
BARCLONE Blogsite -- http://barclone.wordpress.com
BARCLONE Forum -- BARCLONE Forum

BARs helping BARs

SAM 0044
AMA 352635

I find myself re-reading parts of The Handbook Of Model Rocketry, Seventh Edition all the time. After I first got into this hobby in mid-2004, I borrowed a copy of the book from the library but soon decided I had to have my own copy, and I'm glad I have it. It covers almost every conceivable topic in model (and some high-power) rocketry, and has made it FAR easier for me to understand many of the posts on this forum and over on TRF (http://www.rocketryforum.com) that presume some knowledge of the topics being discussed.

I cannot recommend that book highly enough.

__________________
John Thro, NAR #84553 SR
I was too old when I started! Now I'll *never* become a BAR!

Well... I think you guys are over estimating my intrest here... I want to build this rocket, have it shoot up just out of site, and then have it come down so my girlfriend and all her cute little friends can frolick in the field (hopefully in short skirts) looking for it.

I got a 3-pak of engines... and hopefully I can use them all... then place the rocket on a shelf somewhere to remember the day (and the short skirts)

So, buying a book is a bit beyond my plans. I'll try adding some weight to the nose cone. My girlfriend does pottery so maybe I'll use some of her clay.

Thanks guys!

Hmmm....
Seems Charlie has some motives unrelated to rocketry here !

__________________
When in doubt, WHACK the GAS and DITCH the brake !!!

Yes, there is such a thing as NORMAL, if you have to ask what is "NORMAL" , you probably aren't !
Failure may not be an OPTION, but it is ALWAYS a POSSIBILITY.
ALL systems are GO for MAYHEM, CHAOS, TURMOIL, FIASCOS, and HAVOC !

Well we all would like to wish you a most enjoyable day with your rocket (and recovery crew).

.

__________________
Steve Naquin
TRA# 677 L2
NAR# 85518 L2
SAM# 0052

🚀 In Construction: Der Blue Maxx/Minie-Magg 5.5” & Vander-Burn MDRM Clone w/Stickershock23 Custom Decals
🚀 In Paint & Detail: USR Banshee
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🚀 In Repair: SLS Lil’ Hustler, SLS Aero-Dart 1969 Trim
🚀 Stay Tuned For Fall 2021 Launch Dates

Charlie, that sounds like a great plan to me!

You might find that people on this forum and on TRF can be eager to give just a *little* more help than you really asked for.

If you want to be sure to get your Hi-Flier back so your girlfriend and her friends can frolic in the field, an A8 or B6 motor is probably the way to go. And don't forget to use wadding, or you'll melt your parachute or streamer.

Oh, and take pictures! We like pictures here.

__________________
John Thro, NAR #84553 SR
I was too old when I started! Now I'll *never* become a BAR!

It's official. I'm a cynic.

__________________
Bill Eichelberger
NAR 79563

http://wallyum.blogspot.com/

I miss being SAM 0058

Build floor: Estes - Low Boom SST Semroc - Marauder, Shrike, SST Shuttle

In paint: Canaroc Starfighter Scorpion Centuri Mini Dactyl Estes F-22 Air Superiority Fighter, Multi-Roc, Solar Sailer II, Xarconian Cruiser Semroc Cyber III

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