There are many [https://www.andymark.com/Search-s/545.htm?Search=Motor+mount&Submit= off the shelf] motor mounts

3D printed mounts
  - [https://www.thingiverse.com/thing:2165671 Denso throttle motor] and [https://www.thingiverse.com/thing:1970687 another]
  - [https://www.thingiverse.com/thing:1748549 CIM motor] or [https://www.thingiverse.com/thing:438162 another] or [https://www.thingiverse.com/thing:238229 another]
  - [https://www.thingiverse.com/thing:2424501 Snowblower motor]