Does the weight of a spinning gyroscope change how much weight it can sustain (stabilize) Hello I recently watched a video about gyroscopes and I wonder what changes the amount of mass it can keep upright. EDIT: I did search online but I couldn't find a website which explains this in a simple way 
 A: Answer to your question:
The ability of a gyroscope wheel to exert a torque is proportional to:
- the weight of the gyroscope wheel
- the rate at which the gyroscope wheel is spinning  
So: from a purely theoretical point of view there is no upper limit. Even a small gyroscope wheel can push a large weight around, provided the gyroscope wheel is spinning fast enough. 
Of course, in practical engineering you will build something reasonable. 
Let me discuss a practical case, related to your question.  
In the industry of large luxury boats there is a technology called 'gyroscopic stabilization'. When a boat is pointing in a direction parallel to the waves the boat tends to start swaying. The purpose of the gyroscopic stabilization unit is to reduce that rocking motion. The stabilization unit is bolted securely to the structure of the boat. The wheels are spun up to a very high velocity. When the automated system detects the ship being rocked by a swell powerful actuators push the spin axis of the wheels, resulting in instantaneous torques that at each instant in time counteract the rocking motion. 
You can make the stabilization unit smaller, but when you do that you have to spin the gyroscope wheels faster to get the same ability to counteract roll. Higher spin rate means more wear and tear for the moving parts so there is a practical limit to how small you can make the unit.
