I was in contact with the folks at Rapido Trains, who are coming out with a TurboTrain model, and they told me they had looked at the Hornby HO model (or maybe it is OO – I think it is the same track gauge but a slightly larger scale than American HO?) of the Pendolino train that is in service in England.
Apparently that model tilts as it goes around curves in a manner similar to the prototype.
I have scratch built HO trains that tilt, either by attaching the car body to the truck through a roof-level pivot or by using a four-bar linkage mechanism. You have to run the trains fast over rather short radius curves to get measurable amounts of tilt, and then the tilt is hard to see as the train is going so fast. The problem is that the tilt goes as v^2/r where v is the speed and r is the radius of the curve, and that law does not scale linearly down into model scale on account of the squared (^2) term.
Anyone here seen the Hornby model or operated one? Does it swing outward under centrifugal force so the tilt varies with train speed, or is the tilt controlled by the trucks pivoting to go around a curve, and you have the same tilt at different speeds? Is the tilt apparent on that model, or do you have to run that model fast around too sharp a curve to see much tilt?
Apparently the Hornby model is a hit over in England and there are a number of You Tube videos. This video http://www.youtube.com/watch?v=FoaNFLuta64&NR=1 seems closest to showing the model tilt. It seems that as the train enters the second curve, you can see each train car edge jack up as that car starts to tilt, and it seems that effect occurs at a relatively slow speed.
I am curious as to what anyone knows about the Hornby model and how it tilts and whether the tilt is noticable or appears realistic.