Hacker News new | past | comments | ask | show | jobs | submit login
Making a Ponyo boat (jgc.org)
184 points by jgrahamc on June 25, 2011 | hide | past | favorite | 12 comments

We watch Ponyo at least twice a week in my house (4 year old loves it) and I have always wondered about the boat. The first thing I wondered if a.) it was real and worked - based on jgc's post seems that it does and might be more common than I thought and b.) if the heat would allow Ponyo to actually sit on the top of the boat as she does while it is moving.

Pop pop boats are real and have been around for a long time, I had a couple when I was a kid and it was fun to play with. You can see some more examples of pop pop boats and read some history here: http://www.nmia.com/~vrbass/pop-pop/

When I made my first pop pop boat, I simply coiled a piece of small hobby tubing for the boiler, with the ends poking through the bottom of the boat.

I don't get how it works. Can anyone explain?

The heat from the candle flash-boils the water that's in the "boiler". This is ejected out of the tubing, and once the diaphragm relaxes, it creates a vacuum which pulls more water into the boiler to be boiled again.

The reason it doesn't just jerk back and forth in this exchange is because it sends pressure out in one direction, but draws water in from all directions.

The wikipedia article has a subsection that is well explained IMO:


I wonder if the efficiency would be improved if the whole engine construction would be under the surface level.

To a degree, but anything powered by a candle is going to have a pretty low hot-end temperature, and thus miserable thermodynamic efficiency.

Nice. This design of creating a toy boat has been extremely popular in south east asia for atleast the past 20 years. It's good to see it here again. Nothing beats nostalgia. :)

Adding this to my list of things to "invent" should I ever be transported thousands of years back in time.

I wonder how I could make a remote control ponyo, low-tech wise ..

It is possible, all you need is to find the controller which will control the flame, bigger==faster.

Guidelines | FAQ | Lists | API | Security | Legal | Apply to YC | Contact