Interesting - it must be really close to the optimal mass for the K660...

It is now saying 7350 for the K550 in an updated sim, at just shy of mach, but the K660 still gets 13100. A bit slower, at 810mph, but what it lacks in speed it makes up for in extra coast time...

Basically, with the shape I have, any mass from 2 to 12 pounds keeps it well over 12k, and any mass between 5 and 11 pounds keeps it at 13k or higher. Optimal mass appears to be about 8 pounds even without motor (14061 feet, 860mph).

So, it looks like it should be right in the 13k zone, assuming a smooth finish and a straight flight...

Oh - and an L730 sims right at 15K and 900mph

The Cd of the rocket sims quite low, with a smooth finish. Rocksim says about 0.4 for subsonic, 0.75 transonic, and right at 0.7 supersonic (~M1.75 and up).

Only time and a flight will tell, Chris. There's a really good guy, who I certed L2 earlier this year, Jason C., who shot his VA on a K660, I believe, and lost it ath their new launch site in Pueblo, no events heard or seen... I hope he foiund it, but if the altitude is what you say... who knows? Good job! Hope Jason finds his VA! I love that GLR rocket, and I WILL get in in FBG sometime next year.

I launched my VA on a PRO 54 K530SS. It was an amazing boost but I have not yet found the rocket. I may have to look into that fiberglass VA, that is after I get a tracking system.

Only time and a flight will tell, Chris. There's a really good guy, who I certed L2 earlier this year, Jason C., who shot his VA on a K660, I believe, and lost it ath their new launch site in Pueblo, no events heard or seen... I hope he foiund it, but if the altitude is what you say... who knows? Good job! Hope Jason finds his VA! I love that GLR rocket, and I WILL get in in FBG sometime next year.

We'll have to see...

I'm looking forward to seeing the flight, that's for sure.

Oh - and that K530SS should be a pretty nice motor. I'll be using two of them in my Deuce at MHM, so we'll see how they perform. With any luck, it'll break 3k this time 😆 🙄

8) As a side note, I have picked up an all glass Vertical Assault that I am going to fly at MHM on an Pro 54 K660. This is a showstopper load. A full K at 2437ns. with a 3.7 burn time. (It makes a max. 245lb. thrust.) I saw one launched over in Utah. What a motor!! I will add tracking, should get way up there. Bruce, what does your simm say? 8)

Hey Tim, I was going to fly that load at MHM as well. Drag race? 😆

Now THAT I want to see 😯 😆 8)

Oh, that's gonna be sweet! 😈

8) What a great idea! I never thought about 2 of those bad boys! Count me in! Anyone else want to join in? 8)

8) What a great idea! I never thought about 2 of those bad boys! Count me in! Anyone else want to join in? 8)

IF my rocket survives, I'll win the drag race. I only say that because it is a minimum diameter bird, about 4' long, and it weighs a couple of lbs. I want to see if I can exceed mach 2 with my surface mounted fins. This is a really tough rocket, it fell in a flat spin from 24K out at Black Rock and hit the playa with a spent L330 aboard. The fins were fine, although I did have to splice the airframe. The splice won't come into play on this flight, as the area that was spliced will be braced by the motor.

This should be a total whiplash kind of a shot. "Stratagem" is my 38mm minimum diameter bird that I put a J570 into for the club J record. The K660 should go quite a bit faster (though interestingly not a lot higher) than that blast. I've played with the sims, it is good for about 20K. I actually don't think it will exceed 20K, but it may be best to have the higher window in play. I'm not interested in breaking the waiver....

8) What a great idea! I never thought about 2 of those bad boys! Count me in! Anyone else want to join in? 8)

I have a 54md rocket of 4.5 feet length or so, I could toss into the ring if theres enuf hardware...I was gonna fly it on a Loki k350--which has higher peak thrust and a longer burn as well, one of my current faves.
JS

PS: JW--just touches M2 but only gets to 18.5K--this at 40oz dry wt.

If I toss ~65 oz. of lead shot into the rocket, it slows it down by several hundred mph and it actually goes quite a lot higher. I think I'll fly it light, though-- I may want to use this as a sustainer someday and I'd like to push it around some.

It is also a wee bit hard for me to pour 4 lbs. of lead shot into a rocket. I weighed it out, and it actually fits OK.

JW

8) John, I do have 2 sets of hardware for the K660. I have to think that 3 K660 at once would be a highlight. I am also planning to fly one in my Level3 bird. I am going to work up from a K660 to a L850 and then to some sort of M at LDRS. I want to be sure the bird is good to go. I also have an order for a 5th K660. I think the K660 is a nice match for the ATK700. Both have a lot of poop. And they are almost the same money. 8)

If I toss ~65 oz. of lead shot into the rocket, it slows it down by several hundred mph and it actually goes quite a lot higher. I think I'll fly it light, though-- I may want to use this as a sustainer someday and I'd like to push it around some.

It is also a wee bit hard for me to pour 4 lbs. of lead shot into a rocket. I weighed it out, and it actually fits OK.

JW

Did I hear sustainer???? 😉

JS

PS: thats what this is--originally intended for complex L record. Lead has an sg of what about 11.4? 1800gm/11.4=what about 10 cubes if you melt it into a slag, maybe 12 or so is left in shot form. That about right? if so, talking about 54mm x 4 inches?

8) John, I do have 2 sets of hardware for the K660. I have to think that 3 K660 at once would be a highlight. I am also planning to fly one in my Level3 bird. I am going to work up from a K660 to a L850 and then to some sort of M at LDRS. I want to be sure the bird is good to go. I also have an order for a 5th K660. I think the K660 is a nice match for the ATK700. Both have a lot of poop. And they are almost the same money. 8)

Tim,

No sweat, if there's a third set I'll fly it. Problem with the loki is it goes well over waiver limiting our time to do a trio. I test flew my 4" on an AT K1100 which was a pretty good shakedown, skipped L all together and just let it rip on the Loki M1882. But hey I'm all for being methodical--the flip side of course is murphy is nipping at your heels and the more practice flights, the smaller the odds of having an intact rocket to fly an M with. Course it can be argued a failure means you were rushing it.

So if we have the hardware for the trio, I'll do it, otherwise I'll just fly the Loki K350 separately under big waiver.

Is any one using PRO-38?

Mike, forgot to mention that CTI sent us a COMPLETE Pro-38 set of motor casings last year for our raffles. I broke it up last year. But this year, if I get the NCR Raffle Coordinator position, and CTI is that generous this year, I might keep it as one fantastic package! That would be one heck of a giveaway! 8)