Gyroscopic contraption...

[Externet]

A bicycle, hanged off ground.   Wheels turning.  No or fixed steering, (or, both wheels on a rigid frame.)

Trying/pushing to 'topple' it, some torques become active.

If the wheels are turning in opposite directions,  What torques/forces to expect trying to topple it?

 

Next... wheels with their shafts at a right angle.  What torques/forces to expect trying to topple it?

Next... 3 spinning wheels with their shafts in the 3 axis. What torques/forces to expect trying to topple it?

[Enthalpy]

Hi Externet!

Identical parallel wheels, same angular speed but opposite direction: no global torque is required to topple the frame BUT each wheel creates a strong torque, so everything but be sturdy enough.

Two wheel axes perpendicular: nothing special, the net torque is the sum of both. The gyroscopic torque is  the vector product or the wheel rotation (put inertia moments if you wish, I don't care presently) with the toppling rotation, hence perpendicular to both axes. For instance if the toppling axis is perpendicular to both wheel axes, you get two gyroscopic torques which are perpendicular to an other and add vectorially.

Three wheel axes perpendicular: nothing special again. For instance if the toppling axis is parallel to one wheel axis, this wheel creates no gyroscopic torque, and the two other wheels do like in the previous case.