"robot" to ring Tibetan singing bowl?

[djacobow]

I'm building an alarm clock project that will use an RPi to announce appointments from Google Calendar. I would like the announcement to come from a real physical object rather than .wav file and like the sound of Tibetan singing bowls.

This isn't really an electronics question per se. I think I'll have little trouble with the RPi, getting the calendar data, and driving motors. (actually I've already got the calendar code working). However, I don't know how to build the actuator. I want something that is:

- quiet (don't want motor to be very audible relative to bowl)
- simple (probably will have to make any box, arm, etc from wood)
- cheap-ish (<$100)
- won't be super janky looking in the end

Anybody have good suggestions?

By the way, these bells are not rung by striking them, but by circling them lightly with a wand. My initial conception is motor mounted above bowl on overhead support, arm with length slightly less than radius of bowl mounted on motor shaft with want attached by hinge. The motor would spin slowly enough that the wand's own weight would keep it in contact with the bowl.

For those unfamiliar, this is what I'm talking about:
(minus the spiritual mumbo jumbo)

Any better ideas?

Regards,
Dave J

[fcb]

Spin the bowl - buy a lazy-susan or lazy-susan bearing, then use a large o-ring (or make one - it's pretty easy to join o-ring material together) and drive it with either a shaded-pole motor or perhaps, stepper or what ever you can find.

I'd spin the bowl and have some LED's lighting it (candle effect code).

[djacobow]

Fcb, thanks! I'm glad I asked. Yes, turning the bowl makes more sense!

Maybe could repurpose parts from an old turntable, perhaps.

[fcb]

Ommmmmmmm.....

You have chosen wisely grass-hopper.

[djacobow]

Ha ha, we will see! I think it will be nice to wake up to this sound rather than a buzzer.

Were you suggesting that the o-ring surround the entire rotating platform and be driven by a motor in contact with it at the edge? Because that's the picture in my head right now.

[fcb]

You could do it like a turntable (o-ring round the OD), or you could use just push the motor shaft against the OD of the turntable (perhaps use an o-ring to give you a grippier surface).

I'd do it like a turntable personally, but I don't know how much friction the wand applies and if that would cause slipping.