Of course, you could ignite your second stage motors with Parrots in those 18mm tubes, and get apogee deployment and some cool data as a bonus. Might be tough to pull together before this weekend, though. I'll lend you one if you're interested. It looks like with the length of the 2nd stage tubes that it might also be a tight squeeze to put one Parrot in each along with the motor and chutes. It might be better to just put one in the central part of the 2nd stage cradle to ignite both motors. The Parrot you got at the December launch would be perfect for that, especially if you haven't soldered on the screw terminals yet.

Also you might need little beefier moters than "B"s in the bottom. ❓
I think it looks like you have room for "D"s 🙂

I'm just throwing out concepts, and I don't want (or want any of the helpful NCR members) to have to chase the stages very far. C's are probably a better choice for boost, but D's won't work (composites excluded) since I built it with 18mm tubes.

Oh.

They look bigger in the picture.
Adrian, is right. The weight of all those little motors adds up back there.

Maybe Mike's a beta tester for Rocksim 9. It would allow all those additional pods with nosecones and motors.

Ken

...Any way to check the stability on it?

Yes, I verified it with Rocksim 8 and later 9 (as a Beta tester). The HP version has long K700's which move the weight forward. The model rocket version is marginal as an extra motor is used for igniting the upper stage(s).

It turns out we have to be at wedding before 2 PM on Saturday the 3rd, here in Louisville, so making it up to Ault and back for a launch might be dicey.

I'll need to learn more about the parrot yet, but I have many plans for it.

...Any way to check the stability on it?

It turns out we have to be at wedding before 2 PM on Saturday the 3rd, here in Louisville, so making it up to Ault and back for a launch might be dicey.

If its not yours, or one of your kids, you dont have to live with it long if your late! 😉
Besides most weddings all end the same, they say "I do" and then they kiss. Seen one you seen em all. 😉
And unfortunanetly all marrages dont end "Death do they part" . 😯
I had a friend, spent more money than anyone I know (biggest shin-dig I ever did see) on his wedding, and honeymoon. Marrage almost lasted a whole year. 🙂

Yes, I know, I'm a bit cold! 🙂
If your late, you might miss good food though. 🙂

Mike, you continue to amaze us, my friend. Very nice work, on all power levels. NOW I can see what we were talking about. Don't second guess, just light the beauties!

Well, we tried it. As an engineer I'm very familiar with the old saying "Back to the drawing board", and that's where I 'm going.

This cradle rocket concept can only work if both motors ignite within milliseconds of each other while the rocket is still on the rail. Because of the waiver's ceiling of 12,000 feet, I had to use J motors in the booster and both were required to get the speed for stability before leaving the rail. It was designed to accomodate K700's so there might have been a different outcome, but I doubt it.

All 6 electronic modules worked, and believe it or not are all usable again. One thing learned was you can ignite the sustainer from the booster as long as you do it under thrust. The DC20 was having trouble picking up the WAAS because of the dense cloud cover

Both J350's in the cradle fired (see picture #2 in the series below, you'll see a bit of flame in the left motor and smoke in the right motor).

Picture 3 shows only the right motor in full burn. After it leaves the rail, it starts to bend left, then when the left motor finally turns up the wick, it bends back right. (see picture 4) You'll notice the black pair of fins on the sustainer always facing the camera. Fortunately it kept bending so that it went away from the crowd at the LCO table.

1.1 second after 1st movement of the rocket, the timer in the cradle ignited the sustainer and separation occured.

The cradle fell into the earth on the left side of the trailer, jamming the nosecones, so when the deployment charges went off (via dual PML/MW CPR's), it was too tight to separate. (note the backup main charge did not go off).

The sustainer hit the ground on the right of the trailer and broke the tail can off at the top of the motor (the retention held at the top). Though the nose cone hit first breaking the tip off leaving the GPS exposed, I think it was a fairly flat strike, like an airplane pancaking in, as one fin broke off and the sections separated under the shock, both chutes deploying. You can see the drogue shock cord stretched out as that section is flying to the right.

However, none of the 4 charges in the sustainer avbay went off. They were connected to two MW RRC2-mini's. This may be because the rocket never reached the initialization threshhold, or more likely my 8 second mach delay. Before 8 seconds went by, the avbay was laying on the ground so it may have thought it never left.

All three nosecones were damaged beyond repair, but the tubing stayed intact (except for the sustainer tail can).

More comments after the picture sequence...

A very short movie:
http://www.telerover.com/rockets/CR/GoH_Launch.MOV

My goal was to make a multi stage minimum diameter rocket design that was fairly short(and light for carrying as I have a bad back), and had all the deployment options, unlike my K700 to K700 "The Twins".

Unless someone can show me a reliable, repeatable method of lighting two motors simulataneously, the dangers of asymetrical thrust is too great to risk people getting hurt and the amount of work it takes to build these is too extensive.

If I do this again, I think putting deployment electronics and chutes in side pods on the booster, with a central motor would be the best alternative. Still thinkin'....

Mike.
Don't give up on this one..... It's a great idea and we all would love to see this go. You only fail if you quit trying.
Greg

"reliable, repeatable method of lighting two motors simultaneously"
Cesaroni ❗

Seriously, Mike. Make a cheap 38mm version in LOC paper tubing and use the 1 or 2-grain Cesaroni G or H motors to prove it out. I think you'll be pleased. I lit 3 1-grain 38mm G Smokey's for my airstart with just a PF timer and a 9-volt. Surely a club launch system could light them INSTANTLY.

It WILL work!

Ken