We are making a reactive baby bed and are having an issue picking the correct size motor to use for the project. We salvaged a foot spa motor but I can not find any specs to point us in the direction of which voltage rated motor to buy. We have also looked at systems like a bed shaker, vibration back massage pad and hooking up a string of small motors. Any advice, pointers, or help is appreciated.
I think I'd start with a car electric fan motor from a scrappie...
You don't want it too violent, do you? Maybe 12VDC motor from car windshield wiper. Rear window wiper for less power, front window wiper for more power.
Can look at motors here too, with specs on voltage/current & speeds http://www.mpja.com/Motors-Components-Electronic/departments/377/