Would it be better to have the wheel rotate on an axle of a car or have the wheel glued to the axle and have the axle spin? Cardboard Car?
It depends on the purpose, but if I presume this is a cardboard likeness of a pinewood derby car that may be racing down a hill, then I'd say that the the higher rotating mass that includes the extra weight of the spinning axle may keep the car moving better, assuming the steepest downhill part is at the start line. For actual cars with actual people driving them, generally the desired answer is to minimize unsprung weight which would tend to mean having the smallest rotating mass is better and shorter drive axle independent suspension is better than solid axle suspension. There is also a materials question, I should be asking are ALL components of the car cardboard, or the axle is a metal axle, so using metal axles adds the weight of the metal axle, which for a hill launch derby car type race sounds adventageous. But if you have to make a Cardboard axle, maybe it doesn't sound so adventageous.
I was very confused why you would be attempting to glue a wheel of a car to the axle until I saw cardboard. Definitely have it rotate! Put a bigger cap over the end of the axle to keep the wheels locked into place but let them spin! It will add a cool effect, besides, if you glue the tires they might come off.
As the Grandfather of many Pine-wood Derby participants, The Cub Scout Committee Chairman for several years, And as the builder of 2 soapbox Derby cars, the axle should always be stationary, and the wheel should turn freely.
