Micro Gear Motor Eccentric Shaft Adapter

If you need to add some "wobble" to a micro gear motor, this is the part for you! Use it as a button-pusher, switch-flipper, trigger-puller, belt tensioner, or whatever other small lateral motions you might need to create with a rotary motor. The STL file is set for a 12mm cam with a 5mm (+/- 2.5mm) stroke, but this can be easily changed in the SCAD file to whatever you want.

If you don't already have motors, my favorite version is the Pololu Micro Gear Motors (https://www.pololu.com/category/60/micro-metal-gearmotors), which come with carbon brushes and a range of gear ratio options from 5:1 up to 1000:1. Pololu makes a double-shaft version that is perfect for adding an encoder on the back. For most applications where you use a cam, you will probably also want an encoder, but if not, here's a few single-shaft Pololu motors that are available on Amazon:

6V, 75:1 - https://www.amazon.com/gp/product/B00EIAZ4UY/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00EIAZ4UY&linkCode=as2&tag=tac047-20&linkId=DURFWFVG2W6BUF2N
6V, 100:1 - https://www.amazon.com/gp/product/B00EIAZ4UY/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00EIAZ4UY&linkCode=as2&tag=tac047-20&linkId=DURFWFVG2W6BUF2N
6V, 298:1 - https://www.amazon.com/gp/product/B00EIAZ4UY/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00EIAZ4UY&linkCode=as2&tag=tac047-20&linkId=DURFWFVG2W6BUF2N
6V 1000:1- https://www.amazon.com/gp/product/B00EIAZ4UY/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00EIAZ4UY&linkCode=as2&tag=tac047-20&linkId=DURFWFVG2W6BUF2N

...OR... if you don't want to spend $15-$20 per motor, here are a few other manufacturers making similar motors at a lower cost, but i can't vouch for the reliability or quality. If you use these (or have other recommendations), please let me know how they work out for you:

6V, 300RPM: https://www.amazon.com/gp/product/B00EIAZ4UY/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00EIAZ4UY&linkCode=as2&tag=tac047-20&linkId=DURFWFVG2W6BUF2N
12V, 100RPM: https://www.amazon.com/gp/product/B00EIAZ4UY/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00EIAZ4UY&linkCode=as2&tag=tac047-20&linkId=DURFWFVG2W6BUF2N
6V, 30RPM: https://www.amazon.com/gp/product/B00EIAZ4UY/ref=as_li_qf_sp_asin_il_tl?ie=UTF8&camp=1789&creative=9325&creativeASIN=B00EIAZ4UY&linkCode=as2&tag=tac047-20&linkId=DURFWFVG2W6BUF2N