Going back to the ‘OG’ pool-noodle design of a ‘scribblebot’, I made these Star Wars astromech themed designs that feature R2D2 and R5D4.

Here's a list of the parts required:
1x 6mm*10mm DC3V 3.7V Micro 610 Coreless Vibration Vibrator Motor
1x Coin Cell Holder for 20mm*3.2mm Coin Cells (ie - Philmore No.BH2032)
1x CR2032 battery
1x 12x8mm DC30V 1.5A Small ON-OFF 2-pin Push Button Switch (14.4mm CC hole dist)
1x 20mm wire
3x 8.5mm diameter pens

Here's a vid of it in action accompanied by and AI-written script:

If you found this useful, it would bring me great joy to see your work - so be sure to share. :)

Or, just buy me a coffee: 

https://www.buymeacoffee.com/Julius3E8

OR… better yet, please feel free to dump a bitcoin or two here:

1Py3TUeR8noBN2giHyFV1GfB6x3Kh2WEVv

... include a note to the effect of "Hi Julius3E8, thanks for the [insert name of thing]... my life has improved five-fold on account of it and please accept this paltry amount in gratitude".

You're welcome! (in advance) :D

Also, feel free to peruse my other submissions which are almost as varied as they are many:

https://www.printables.com/social/320993-julius3e8/models

http://www.thingiverse.com/Julius3E8/designs

Enjoy!