Posted on 12/30/2012 8:35:51 AM PST by Hardraade
This is a typical howto-question.
Take a typical 7.62 bullet. Posit that it knows exactly where it is, and where it should be.
How do you change direction, with the equipent being small enough to fit onboard with the position sensor?
I think you are referring to the plasma jet formed by the Munroe effect when a High Explosive Anti-Tank (HEAT) round strikes its target.
http://en.wikipedia.org/wiki/Shaped_charge
The sabot in an anti-tank round is a spacer that keeps the long tungsten (or, in the case of the M1, depleted uranium) penetrator centered in the shell casing during handling and initial firing. Since the penetrator is essentially a large, very hard dart, a base plate is needed to allow the expanding propellent gases to deliver their full power to the penetrator; otherwise, they would just blow past it. Once the penetrator, sabot, and base plate exit the bore of the cannon, aerodynamic forces peel the sabot and base plate away and allow the penetrator to speed to the target, usually at speeds well in excess of 4000 fps. These rounds are referred to as Armor Piercing Fin Stabilized Discarding Sabot (APFSDS) rounds.
While both deliver kinetic energy to the target, the HEAT “penetrator” is created only at the moment of impact. The penetrator in the APFSDS is manufactured component of the round.
As for the Sandia self-guided bullet, it might have useful applications in sniping, if you can get the electronics to survive the shock loads from firing and the guidance mechanism to function properly. Not an easy task, even in a much large diameter round. See, for example:
http://en.wikipedia.org/wiki/Extended_Range_Guided_Munition
Aha!
Gaffer,
By the time I got my post written and well...posted, several others had already answered.
Sorry for the late hit.
Gaffer,
By the time I got my post written and well...posted, several others had already answered.
Sorry for the late hit.
You get only one shot.
I had considered microfins or vanes, but they’ll likely interfere with the spin which I need for other functions (power and clock). Maybe tweaking the things internal weight balance would be the way.
You get only one shot.
I had considered microfins or vanes, but they’ll likely interfere with the spin which I need for other functions (power and clock). Maybe tweaking the things internal weight balance would be the way.
A fluid gimballed INS system with backup starshots at the top of the ballisic arc like the MX?
I have pondered this one for a long time.
The answer, I believe, is lift vector modulation.
Look up and read about how the Gemini and Apollo capsules changed directions. The answer was an off-axis thrust that changed the effective center of gravity, which caused lift in a particular direction.
Well, that isn't very practical in a bullet spinning at 50,000 RPM or more. The answer there is a spin-angle sensor and a peizoelectric actuator with a weight on it, controlled by a microcomputer.
In the relaxed position, the weight is in the center of the bullet, and the lift vector is neutral: bullet goes straight forward.
To move to the side (or any radial direction), the actuator is used to push the weight slightly off-axis for a certain number of degrees of rotation, in the opposite direction that the bullet needs to go. This is repeated for a number of bullet rotations proportional to the desired turn angle, and inversely proportional to the actuator weight. This alters the lift vector and "turns" the bullet in the desired direction.
I think the whole thing would have to be micromachined on a single chip, kind of like the digital micromirrors in a cinema projector. It would take very little electrical power, yet would require high voltages for the actuator. But I think it could be done.
Sandia’s Self-Guided Bullet Prototype Can Hit Target A Mile Away
armedselfdefense.blogspot.com ^ | 02/01/2012
Posted on Wednesday, February 01, 2012 1:10:09 PM by Sasparilla
http://www.freerepublic.com/focus/bloggers/2841187/posts
As I said before, sort of, Sandia is microfins/vanes and will interfere with the other stuff I want in my magic bullet, like the spin which will provide clock and also power for computation.
Basically, I want long-range fire-and-forget from a rifle that is outwardly just another sporting rifle, maybe even a simgleshot.
Lift vector modulation sounds promising.
Anyway: what I’m after is the technology for a militia. And not just this thing.
It should be items and concepts that the government (any government) does not have, let’s say a lead of 10-20 years. That, gentlemen, is way easier than it sounds. One of the H&K specialty items is almost certainly mine, grabbed by our verson of DARPA many years ago when I was required by law to let them have first look. But we have some of the smartest ppl I know, right here on FR. We can probably outrun what the establishment has become.
How about a traditional muzzleloader that looks innocent but is able to take out an office building? Way easy.
Micromachining was mentioned here, would that be a track for 3d-printing?
As I said before, sort of, Sandia is microfins/vanes and will interfere with the other stuff I want in my magic bullet, like the spin which will provide clock and also power for computation.
***Firing a small battery as part of the terminal mass on target will give you power and with a 555 timer, a clock. Once you free yourself from rifled barrels, you could further disguise your prize by having it not even look like “just another sporting rifle” in the first place, by screwing in the barrel at the last moment you intend to use it. To further the disguise you could add plastic to the outside and make it look like a camera, or a wok, or a radio or whatever — rather than looking like a sporting rifle is still going to draw attention to you. Why are you limiting yourself to 7.62? Basically you need more room for whatever electronics and magic you want to add, which is why the DARPA project is going for .50 caliber.
Darpa, bah.
There’s two reasons I want a plain vanilla hunting bullet/rifle setup:
1. Appearances.
2. Regulation. Expect the 50BMG to become a threatened species, and the Barrets and others likewise.
Now, of course, when we’re looking at “traditional” muzzleloaders we have flexibility. These things will never get banned, and they can fire bullet sizes dmn near to a torpedo. So we’ll be looking at agents. And there are agents much easier to procure, easier to handle, and deadlier than a nerve load. And not listed as WMD, either.
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