Hmmm....Maybe then three B6-0's. I thought that the D12 had a slightly longer burn time. Thats what I get from operating from memory. Staging would take the strap-ons off with the 1st stage. Might be some interesting flight pattersn for that last 0.15 seconds on the C6's. Too bad the B14 ain't around anymore.

Back in the 1980's during my second BAR-hood, I built a 2 stage 24 mm that used 2 of the CMR strap-ons. I used B14's and C6's in the strapons and had good success with it. The main rocket itself was a kitbashed Challenger II (without the fin can) and it was used to boost my astrocam. Worked great. I launched it several times. Had only one ignition failure with the strap-ons.

Hell Craig, if I flew that stack and it WORKED, I'd have to change MY underwear!

__________________
Quando Omni Flunkus Moritati

Maybe he could design the decal for this rocket!

The one time my 2 stager with strap-ons had an ignition failure, it took off and went up about 50 ft or so, went almost horizontal, but luckily on a slightly up angle. It stayed in that attitude through staging and went a LONG ways downrange, plowing into the ground before the ejection charge deployed. Dinged up BT and busted fins, and a scratched up astrocam.

I used the battery on my Ford Ranger and a FSI launch system with a cluster whip and the Estes solar 2 ignitors.

All,

I am attaching some new JPG files of decals for the Cherokee Double-D and Triple-D conversions. Higher resolution TIF files have been sent to Scott for posting on BARCLONE later, but these "might" be good enough to do something with...

Craig McGraw

Attached Thumbnails

     

I don't suppose the camera package came with anything like a dimensioned three-view, did it? That might prove to be very helpful in designing the mounting brackets needed to fit the BT-55 tube.

Craig...

Better yet, you can view the dimensions here at boostervision.com;

http://www.boosterworks.com/cart/sc...sp?idproduct=71

__________________
Quando Omni Flunkus Moritati

I went back to RockSim this morning and re-entered the design, due to some errors that caused the Beta to crash. This simulation includes the weight of the BoosterVision MicroCam and some "fudge factor". As I started looking at the simulation results of the Triple-D without any strap-ons, I spotted something rather disturbing:

The launch rod is 48" long, 3/16" diameter. It takes 64.25" for the rocket to achieve a stable velocity.

"Houston, we have a problem!"

According to the printout, the rocket needs to be traveling at 44 fps to be stable, but when it departs the end of the rod, it's only doing 40.3 fps. Now, the simulation allows the rocket to continue flying in an upward manner, but I did notice a distinct tilt as the rocket goes into free-flight.

What this says to me is, the Triple-D actually NEEDS those strap-ons to get off the rod quickly enough to achieve stable flight.

Nuke, I don't know if you suggested this as just something fun-to-do with the design, given that it was already over-the-top, but you're idea of those strap-ons was absolutely right. By itself, the D12 just doesn't have the "oomph" needed to move that beast. I would be happier if we had a really good, reliable, STRONG black powder E for a booster, as we only need an additional 4-6 fps to make it safer. I'm not sure if we need the power of three C6s, or even three B6s; we might be able to achieve the needed results with three A10s and some BT-5-based strap-ons.

I've got to go back and read TVMs description of simulating strap-ons again. If I can get a good simulation created, I'll post a new copy of the Triple-D here.

If anyone has additional suggestions, SCREAM!


Craig McGraw

Actually, I suggested it because I love the idea of strap-ons on a multistage rocket. (My favorite REAL rockets are the Titan 3 and the various Deltas.) I was really into this concept in my first BAR-hood in the 80's and used several of the CMR Marcus strap-ons as often as I could, especially on the Astrocam carriers. If I can get the time someday, I'm gonna rehab the four I have still and start using them again, and make a few longer versions to use on a 3 stage rocket, maybe a Comanche 3 using an old second stage from one I built in the 80's in place of the first stage. Or better yet, upscale it to a BT-55 and use 24 mm engines on all three stages and 18mm strap-ons! Hmmmmmm............

Too bad someone won't recreate a new reliable version of the old FSI E60. With that beast you could really get a 3 stage BP rocket going. I built one that was a 3 stage F100/F100/F7. I only got one launch out of it, as the sustainer drifted off to model rocket purgatory (even on a streamer, **** that Texas wind!) and the second stage went into the tall weeds/grass and was never seen again. (I quit using green paint after that!)