Listen to JW. Remember how some kids would burn ants with a magnifying glass? This is far more powerful. So don't get excited and accidentally look for your rocket in the sun. It'll be the last thing you see. 😯

Bob's rocket was 10 ounces. Mine was 10 something, but simmed at a lower altitude. Remember mass. If you get 13.5 ounces flying fast, which will go farther... 13.5 ounces or 8 ounces? Think momentum. Of course, 8 ounces will get up a little quicker... but what mass will keep moving longer after burnout? I tied really heavy washers to the Kevlar harness in order to bump it up 3.5 ounces. This is just a trade-off I made. We'll see if it pays off. Might, or Might not. That's the game. 🙂

I realize that. Mine has quite a high ballistic coefficient though, and keep in mind that I have smaller fins. Rocksim says that I have optimum mass, though we'll have to see...

Should be interesting, no question

Since I haven't used Rocksim since it first came out, and I use SpaceCAD, does Rocksim allow you to add a weight and change it so you can see, in simulation, the change in altitude? Chris, at this point, we'll just see what happens. With these G80's prone to CATO and depending on the MAWD to ignite the drogue charge, etc., all I want is a safe flight... with my MAWD back. 🙂 As Bob Messener said, "There are so many variables..." And, that's right. In this case, may the best and LUCKIEST man win. 😉

Another note: my speed multiplies out to 974.1 m/hr. What's Mach 1 at NCR's sites? 760 m/hr? Or what? If it's close to 760, then I'm at Mach 1.28. Oh boy... this can't be right? Okay, checked online, and it's 717 m/hr. It was always my understanding that the number changes with location, as in altitude? If not, then it's Mach 1.35... maybe I should have used a pointy nosecone... 🙂 Ah, second thought get you into trouble...

930?

How on earth...

Mine sims at 830, and it is lighter and (theoretically) less draggy than yours...

That sounds like bad motor sim data to me...

As for the rocksim question - it has a feature where it runs a lot of sims tweaking the mass slightly, and then tells you the optimum mass. Really handy at times (and it predicts my optimum mass as 8.4oz, so I'm a hair over).

Bad motor sim data? Chris, that's what we've been talking about since May or so! 🙂 And Rocksim and SpaceCAD use the exact same .eng files. That's why I can't put too much trust in either sim package for this particular motor. No biggie. Gonna be fun though!

Can you post the .eng that you've been using?

I'd love to see it, just to compare it with the one I've been using.

I know about the bad data talk, but that sounds like REALLY bad data.

Here's the Aerotech data that I have, including the G80 I have been using...

http://www.rocketryforum.com/attachment.php?s=&postid=366292

I can't use your file, since my Rocksim trial date is long gone. Any file I send you, unless I get the data out directly, since you don't have SpaceCAD, will do the same for you. At least, I think so. What specific .eng data do you want? I can pull it out manually.

The file I posted should be compatible - it is a .eng and I can open it in my trial of spacecad with no difficulty. Try it...

Also, if you post .eng data, rocksim can use it. They are mutually compatible (or should be) unless I use the more versatile .rse format (can store more data) which is specific to RS8 (it can use either .rse or .eng files).

I'll get back to you on this... 8) okay, if you have a relatively recent version of SpaceCAD (3.1?), even a trial one, it should have the same .eng files. You can access it by going to Options and selecting Launch Engine Editor. You can compare them that way. If you want me to e-mail you the engine file I'm using, just PM me your address, and I'll forward it.

Well I started my sss bird today, curious whether anyone else is planning to fly next week?
JS