Activity

Yes, I’m going to do a production run.Edward

Yes, you are right. I remembered the dry weight wrong. My calcs show exactly 500 grams, but that still puts it over what you recommend and what Adrian’s dry weight probably was. I’ll take another look.For something that is ripping…   Read more»

Many flyers more experienced than I have warned about the issues near Mach 2. For my 30K shot last year, I added a significant amount of weight, as I didn’t want to mess w/ the velocities that I was anticipating….   Read more»

Since there is a roll-off in drag above mach, there is an advantage to being light enough to get “over the hump.” Maybe that is both the core of RockSim’s problem and the secret weapon to higher altitude.My current strategy…   Read more»

Many flyers more experienced than I have warned about the issues near Mach 2. For my 30K shot last year, I added a significant amount of weight, as I didn’t want to mess w/ the velocities that I was anticipating….   Read more»

Yes, you are right. I remembered the dry weight wrong. My calcs show exactly 500 grams, but that still puts it over what you recommend and what Adrian’s dry weight probably was. I’ll take another look.For something that is ripping…   Read more»

One wild card for everyone here – I truly believe the older Rocksim versions were far more accurate (on a number of levels). I threw away the newer versions and have used v4.0 for a long time. That was largely…   Read more»

I doubt I’ll get around this summer to building a I600 shot to go up against Adrian, but I have messed around with RockSim enough to know that the optimal mass calcs are wacky. First, there is some hysteresis in…   Read more»

I like the idea of doing controlled experiments – I’ve got a Carbon Fiber Mongoose 38 on order – its a minimum diameter high performance bird that should be a great kit. I built and flew my Mongoose 54 to…   Read more»

Adrian, keep posting as you progress so we can see if the optimum mass “theory” is really true; and if so, HOW true, being that there really are numerous variables involved: drag, NC shape vs. expected velocity (i.e., conical Mach…   Read more»

The optimal mass varies a lot with the rocket drag. With a draggier rocket it helps to have more mass, and less mass for a lower-drag rocket. I left mine relatively light because there was so much variability in the…   Read more»

And, was Adrian’s rocket AT optimal mass with that motor? Too many variables… my head is beginning to hurt…

Also keep in mind that optimal mass varies with the motor. In other words, the same rocket would have very different optimal mass calculations if flown on a K1100 vs a K185 – both of which are 1500NS motors.

I know, JW. Now, I’m confused. I always laughed at those who said that lighter flies higher… since optimum mass flies farther, in theory, during coast phase (essentially the same drag but greater momentum, like the golf ball). Now I…   Read more»

Corrections made. Apologies to Scott, Ken and Mark. I just hope someone wins this outright so I don’t have to calculate the N-sec. used to get there in a tie breaker. Could be too much for my bean counter and…   Read more»

UmmActually this is my third time up!Who would of known, you would have to apply all the science and technolagy learned by NASA in the last 60 years for a “D” and “E” shot. 😯

This will be interesting… It would be very hard for me to start over if I biff it now.My “L” shot will be the toughest, as I will be attempting it in a rocket that clearly wasn’t meant for an…   Read more»

PS Look for my L3 on 7/11.

Actually, the K attempt was beautiful. It was the L that burned up.Reatsrting is not such a hard decision when you’ve only burned a-D or E. After burning a K and an L already, I’m not sure starting over would…   Read more»

It’s tempting, but in order to get the Raven altimeter done, I’ll have to skip some launches like the upcoming Hartsel one to carve out more time for firmware development.Good luck on finding Synergy.