Is it ok for stepper motors to be hot?
The maximum operating temperature can be found in the specifications of your steppers. Usually the ambient temperature operating conditions are limited to 50 &deg;C with a maximum operating temperature in the range of 70 - 100 &deg;C. For instance, the steppers I use are limited to a temperature of 80 &deg;C. It is however advised to keep this temperature lower, e.g. to max. 60 &deg;C to prolong the life. Do note that very high temperatures could be a problem for "self-printed" stepper mounts of the wrong material (materials with a low glass transition temperature).

To answer your question: "Yes, steppers may get hot, but if you want them to get too hot is up to the mounting system and how long you want to use them."