# Automate a rocking bassinet without damaging it.May 30, 2011 11:30 AM   Subscribe

We have a beautiful bassinet. How can I make it a beautiful self-rocking bassinet?

We have a new baby and a very nice rocking bassinet. I'd like to put a gadget under it which will gently rock it by applying a gentle force to one of the runners at a timed interval. Ideally this would be adjustable in terms of tempo and force, battery powered, and inexpensive. It would definitely need to be removable and leave the bassinet unscathed. The closest approach I've found online has been for Halloween / haunted house displays, using a windshield wiper motor and matching power supply, which is almost definitely overkill for the amount of force this would require. I'm guessing that one approach might be to use a Lego or erector robotics set, but I'd have no idea what to buy. I'm fairly handy and not afraid to do some reading and research to get this to work, and I'm a programmer so I wouldnt mind if this became my introduction to arduinos, although I'm guessing this won't benefit from that level of sophistication. Thoughts?
posted by condour75 to Technology (2 answers total)

I will chime in here with a side note that should assist you. You say you want it adjustable in terms of tempo... I am going to suspect that you actually don't. That bassinet is basically a pendulum that is going to want oscillate at its own frequency. If you try to force it against that frequency, it is going to be either turbulent, out-of-control, or require far more force than it should...

Put the bassinet on a hard surface, put something baby-weighted where the baby would go, and give it a push. Document its natural frequency under those conditions. Whatever you do or use to excite this pendulum in your solution, you are going to want to do it at that approximate frequency...

The other piece of this that I might suggest is to make the device inertial in nature instead forced. This way, if you touch the bassinet while it is moving, you don't break a linkage or burn out a motor. So basically, a motor with an off center weight attached somewhere near its center of mass (this would require a biggish motor and weight). Alternately, you could install a heavy, well-lubricated pendulum that oscillates with the same period as the bassinet. Then you give it a poke and it should keep the bassinet moving for a good long while (unless the runners are on carpet or something).

Anyway, just stuff to think about, I am interested to see/hear-about what you come up with!
posted by milqman at 12:13 PM on May 30, 2011

What about a low-tech solution like the springs used on a rocking chair?

It may even be a more pleasant rocking feeling as it gradually slows down. You can adjust the rocking force due to how far you pull it back to start it off. I know you want the device to be removable, so perhaps you could have something that clips on over the runners of the bassinet on to a stable base. Or maybe you could hook a spring to a wall and to the runner of a bassinet which might be another way of keeping it going for some time.

To answer your question though, I think an arduino board would be an easy way to do this using electronics. Using an arduino with an accelerometer you could keep track of how much the bassinet is moving, and then once it stops, you could apply a gentle force using an actuator to start it rocking again.

Sounds like a great project!
posted by a womble is an active kind of sloth at 1:42 PM on May 30, 2011

« Older How to disclose that I have the hymen from hell?   |   What kinds of government-sponsored assistance... Newer »