From the Rolls-Royce experimental archive: a quarter of a million communications from Rolls-Royce, 1906 to 1960's. Documents from the Sir Henry Royce Memorial Foundation (SHRMF).
Theory on high-speed steering wobbles caused by conical precession and a proposal for a testing apparatus.
| Identifier | WestWitteringFiles\N\July1925-September1925\ Scan178 | |
| Date | 29th August 1925 | |
| HS{Lord Ernest Hives - Chair} from DA{Bernard Day - Chassis Design} DA{Bernard Day - Chassis Design} 10 — 29.8.25 High Speed Steering Wobbles X457 / T8L+SO Mr Royce is anxious to prove if possible that the wobble set up is due to conical precession without torque, or with very little torque. As we have previously pointed out to you, the moment of inertia of the wheel about its king pin is (apparently) much less than that about the axis of rotation, whereas for conical precession at the same angular speed & rotation it should be the same. I_R w = I_p Ω cos θ = approx I_R w On the other hand the moment of inertia of the wheel etc about the Centre line of the car, is much more than that about the axis of rotation. The theory is that the wheel may be precessing about some point which is a mean of the two and to demonstrate this Mr Royce would like to have made some little apparatus with an indicator - the enclosed sketch is intended to lead you close on any detail of measurement, & to get you started on some apparatus. The apparatus is to be suspended by a spring to simulate the suspension of the car. DA{Bernard Day - Chassis Design} | ||