Kite Plans • Hacker News Board

Re: Kite Plans

#51

Post by shaftway » Wed, May 22, 2019, 8:46 PM UTC

fotbr wrote: post #47

shaftway wrote: post #28

Earlier quoted context omitted.

Not that narrow. I remember in the late 80's / early 90's Estes had a model rocket that would pop a picture (onto film) from the nosecone when the chute charge went off. I have no idea what the quality was like (my parents refused to buy me one).

I spent a bunch of allowance money on one of those. It used 110 film cartridges, and had a pretty cheap plastic lens. Quality wasn't really that good (and wasn't helped by the cheap film I had to use), but it didn't matter to a 10 year old -- I had a rocket that took pictures!

10 year old me is super jealous.

Re: Kite Plans

#52

Post by mushtar » Wed, May 22, 2019, 9:05 PM UTC

Sharlin wrote: post #49

Maarten88 wrote: post #44

Earlier quoted context omitted.

A racing surfkite like this one [1] has no problem going upwind really fast. [1] https://www.youtube.com/watch?v=ltDLsumdXLA

I understand how sailing upwind works with a bermuda rig, but how do you do that with a kite, aerodynamically speaking?

It works the same way, the kite acts like a wing and provides pull and something (kiteboard, fins, hydrofoil, etc.) resists that pull and provides a perpendicular force to the force from the kite power line.

Re: Kite Plans

#53

Post by contingencies » Wed, May 22, 2019, 11:21 PM UTC

semi-extrinsic wrote: post #46

pacaro wrote: post #21

Earlier quoted context omitted.

My understanding is that there are a variety of advantages: the kite flies in cleaner air; the thrust from the kite is applied at one point, with less heeling moment than from a sail; the design of the boat is not constrained by the structural requirement of a mast IIRC A kite powered boat called Jacobs Ladder held various sailing speed records at one point

There was a company out of San Francisco some years back that built several versions of an auto-foiling kite powered trimaran. It looked really cool. https://youtu.be/1QzT_PBLSXo

37knots 12-18 knots of wind

Wow. I couldn't get over how flat the thing sat in the water... no heeling at all. I guess that is a joint property of removing the mast (ie. reducing unnecessary vertical offset prior to thrust distribution across the hull) plus curved foils / mini-keels visible a the start and end of the video. Impressive stability given the low profile in the water.

Re: Kite Plans

#54

Post by SamPatt » Thu, May 23, 2019, 1:43 AM UTC

Kite building is actually fairly easy, and can be very inexpensive. With just wooden dowels, fabric, simple sewing and simple rope & knots you can have something flying in a few hours.

Takes a while to get the hang of troubleshooting the problems of flying, but the basics aren't complicated. Good cheap fun.

Re: Kite Plans

#55

Post by silentguy » Fri, May 24, 2019, 3:48 PM UTC

TACIXAT wrote: post #37

I was thinking recently that kites could make great signaling mechanisms for backpackers. It would be relatively light in your pack and can get a location noticed if you got lost. I'll have to dig through this site for simple designs that are easy to keep up in the air.

Helium balloon would be a better option. Release it with other end tied to your backpack.

Re: Kite Plans

#56

Post by semi-extrinsic » Sat, May 25, 2019, 7:44 PM UTC

contingencies wrote: post #53

semi-extrinsic wrote: post #46

Earlier quoted context omitted.

There was a company out of San Francisco some years back that built several versions of an auto-foiling kite powered trimaran. It looked really cool. https://youtu.be/1QzT_PBLSXo

37knots 12-18 knots of wind Wow. I couldn't get over how flat the thing sat in the water... no heeling at all. I guess that is a joint property of removing the mast (ie. reducing unnecessary vertical offset prior to thrust distribution across the hull) plus curved foils / mini-keels visible a the start and end of the video. Impressive stability given the low profile in the water.

Yeah, I'm curious why these are not more widespread. Maybe it's not as "cool" when it doesn't heel? And probably not possible to run in any regattas with that kite.