"Its A Dud"

[shotoneup]

Hey guys,
Here is a piece of scrap metal that's the inspiration for an Oddroc I'm building. I'm stacking and shaping styrofoam that will be the core that I'll fiberglass over to become the body. The fins will be plywood and fiberglass. I just hope I can get it to fly right without having to add a lot of weight to the nose. Pictures attached. Comments please.

Thanks,
Harry Keyes

[luke strawwalker]

Looks cool...

I've been toying with the idea of making a Mark IV atomic bomb... Always thought it looked rather elegant... I figured that making the tapering body out of fiberglass laid up over a form carved from flower foam balls/cones from Hobby Lobby would be the easiest way to go, then dissolving the foam out with acetone once the fiberglass had set up.

It would be cool to set the thing up for rear ejection with the parachute coming out of the rear, similar to the high-yield hydrogen bombs dropped from B-52's, though of course the Mark IV was never parachute retarded...

Your project looks pretty similar... OL JR

[rocketguy101]

been dumpster diving at Pantex again?

that will be cool looking...be sure to plaster "inert" all over it, or you might have a visit from federal authorities!!

[shotoneup]

I finally finished my oddrock copied from the ordinance tailpiece. It shows to be stable, but I couldn't figure out how to figure the fin box section in on
Rocksim. I know there has to be some Rocksim experts out there. What do you think.

[shotoneup]

Here's another picture, from a different angle.

[MarkII]

Beautiful build, but I wonder: if the fins are in the bulbous nose cone's aerodynamic "shadow," will they be able to do their job? Gravity bombs aren't propelled; they simply follow a ballistic trajectory to the ground after being dropped from above. I'm guessing that the fin assembly on them is there to keep them from tumbling as they fall? If so then they might not be adequate for the job that a rocket's fins must perform. I hope that I'm wrong about this, because I really like your build.

[SMR]

Beautiful build, but I wonder: if the fins are in the bulbous nose cone's aerodynamic "shadow," will they be able to do their job? Gravity bombs aren't propelled; they simply follow a ballistic trajectory to the ground after being dropped from above. I'm guessing that the fin assembly on them is there to keep them from tumbling as they fall?

Very nice looking build. I think (with no written documentation to back me up) that the airflow around the bomb part "wraps" a little to still get to the fincan, else it would be useless on the real bomb as well. Kind of like the laminar airflow over a wing, or around the relatively fat body of a scale V2. The fin assembly keeps the Cp behind the Cg for stability. On a real bomb, though, the Cg will be substantially forward, so this one will need a lot of nose weight. I suppose if you just dropped one of our rockets out of an airplane, it would line up with the relative wind in the direction of fall, just like a bomb would.