Short range targeting (2023 Update)

I want to "hit" a fixed spot with a physical object over relatively short distances (< ~20 ft).

This must not present a danger to nearby bystanders (in the event of a "misfire"). "Weapons" are out of the question.

And, the object must be of sufficient size to be clearly visible in transit. This also suggests a low transit velocity.

I figure I need a bit of mass to ensure aerodynamic effects don't bugger the calculations. E.g., a softball would be better than a softball-sized hollow ball which might exhibit more nonlinear behaviors as it transits from projectile to ballistic motion.

The target is (effectively) a "spot on the floor". I.e., not a vertical "hoop" to pass through (like goalposts in soccer).

Accelerating a significant mass would likely prove to be a challenge so "lobbing" the object seems more practical. It would also *seem* to be more tolerant of aiming issues than something HOPING to travel in a straight line (like a bullet).

So, conceptually, a tube ("barrel") to guide the initial segment of flight and some sort of mechanism to propel the object from the tube.

Pneumatic, hydraulic, mechanical, etc.

Will the control over the propulsive force be the tougher challenge or the precise aiming of the launch tube?

[You are given (r,theta) to target and no feedback as to proximity of strike -- unless a direct strike. The target -- or launcher -- will move after each attempt]

Of course, "you" is a machine...

Reply to
Don Y
Loading thread data ...

A horse shoe probably wouldn't be what you're after. A bean bag for a corn hole game? Build a gun using electrical conduit? An 1 1/4" piece with end caps on it might fit tightly enough in a 2" or 2 1/2" to be blown out with an air gun.

Reply to
Dean Hoffman

mini trebuchet, catapult, or springboard.

friction on the insides of the tube unless you use plenty of lube or some sorte of sabot. (hence my favouring open designs)

Reply to
Jasen Betts

I'm loving the slip into alcoholism posts you make.

Reply to
Cydrome Leader

  • 1
Reply to
Rick C

Yes. They are great fun. There is a bloke near me who has scale model fully operational trebuchet able to lob a water melon about 200m!

It is very impressive and apart from the beam quite compact. When things return to normal I might try and catch up with him again to film it in action. He does charity gigs with it from time to time in normal summers

- needs a *lot* of space. (and careful crowd control down range)

This is the biggest one I have seen online and representative of the sort of design that would work. Camera work is pretty good too:

formatting link

Reply to
Martin Brown

Build a ramp similar to a ski jump. Use a golf ball and you can adjust the angle of the ramp and how far up you let the golf ball go from. You can probably cut a PVC pipe in half long ways and use an elbow of 45 deg at the bottom. Or do not cut the pipe but put holes in every 6 inches or so to drop the ball in.

Reply to
Ralph Mowery

Ping-pong balls can be aimed well and aren't very dangerous.

I once played with the world's 16th best player. I couldn't return a single serve and his shots did bruise. He applied so much spin that the balls hit my paddle and exited at 90 degrees, typically hitting the ceiling.

He was a not very good EE.

I also took a college course under the world's #1 doubles badminton player. His rule was that if anyone ever retuned one of his shots, they would get an A and not have to show up any more. Nobody ever did.

Reply to
jlarkin

See you and raise you:

formatting link
At Warwick Castle there's a copy of Edward 1's Warwolf.

Here's a similar example;

formatting link
Cheers

Phil Hobbs

Reply to
Phil Hobbs

A nerf gun.

Reply to
David Eather

ElectronDepot website is not affiliated with any of the manufacturers or service providers discussed here. All logos and trade names are the property of their respective owners.