Freight Car Physics and Friction/Roller Bearing Trucks
Started by mjs21012 posts2 min read
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I was curious, when updating physics of freight cars, do you have to take into account whether the car has roller bearing or friction bearing trucks? When doing some models and using the freight car physics update guide (available here in the library), I do not see any indications that it offers differences betweent the two styles? Is there a significant difference between cars with roller bearings verses ones without as far as physics are concerned?? I know roller bearings are suppose to allow a car to roll better with less resistance, but I do not know if there is enough of a difference that would make it worth while to add this into freight car physics or not. If so, is there a simple way to do incorparate friction or roller bearing into the physics line? Thanks for any ideas or comments! Enjoy the day!Mykel
RE: Freight Car Physics and Friction/Roller Bearing Tru
There is certainly a difference in starting friction. Friction bearings have a much higher friction at a dead stop than they do at a few mph because there is metal-to-metal contact when the bearings aren't rotating. Roller bearings don't exhibit this phenomenom to any great extent. As for the differences when in motion, I'm still trying to find sources for that. I've long wanted to update Fcalc so that one can choose between friction and roller bearings but I've lacked the hard data to do so. I've heard that when rolling friction bearings are pretty close to roller bearings, but I'll take that with a grain of salt until/unless I can get hard data. If anyone can link to some studies comparing roller and friction bearings it would be greatly appreciated. Also, does anybody have more detailed friction equations than I've been able to find? Specifically, I would like to have data for many different types of freight cars so that I can include more options when/if I update Fcalc(no promises or release date for that either-when/if it's done it'll be released).