Skip to content

Comment on The Lofstrom Loopparent

Comments

its an old idea and until my last search around two years ago I've found almost nothing.

In my infinite spare time (in retirement or something) I plan to build one of a scale large enough to launch something like a water balloon or maybe paintball payload a couple feet. I'm well aware there are simpler and more efficient ways to toss a water balloon ten or twenty feet, but its unlike there exist any cooler ways to do it. I would take it to the local maker faire and set it up next to the guy with the pumpkin trebuchet (every faire seems to have one of those guys).

It turns out that shock loads can be significant and dynamic stability is not exactly guaranteed, which makes it a cool engineering project. Also for small ones either the payload has to be extremely small (resulting in the paintball payload) or the loop has to be extremely heavy (probably not insurance approved, although it would be cool to spin up a length of hoist cable).

The one thing I have found is a cat or kid toy implementation radius about one foot. Its moderately cool. In order to eliminate or cut down on medical bills it has some elaborate and extremely fast motor current monitoring, which is usually the downfall of the toy.

If you're thinking the same thing I'm thinking, I wish you good luck. Its a cool project idea.

This topic comes up almost like clockwork on HN every couple years. Eventually I'll have something cool to demo.

"The one thing I have found is a cat or kid toy implementation radius about one foot."

- Citation please :)

I am unsuccessful at finding the kids toy. I owned one, maybe ten years ago. Hand held, black plastic...

An artist named Paolo Salvagione made an arduino controlled "string fountain" a bit less than a year ago on this principle. It would have to be dramatically up scaled to launch a paintball or similar. His artistic interpretation was the vibration modes of the string look nice and artsy, whereas the engineering launch device I'm thinking of would be a perfectly non-vibrating circle.

Awesome. Putting something on this string that tries to passively slightly bend the string while allowing the string to pass through should be enough to have it lifted and kept up.

AboutSource Built by g1lg1l

Hackerly is an independent reader for Hacker News, built on the public HN API. Not affiliated with Y Combinator.