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).
Production difficulties and efficiency issues with the New Phantom steering system, particularly its failure to self-centre.
| Identifier | WestWitteringFiles\O\2January1926-March1926\ Scan135 | |
| Date | 1st March 1926 | |
| To DA.{Bernard Day - Chassis Design} from Hs.{Lord Ernest Hives - Chair} NEW PHANTOMCodename for PHANTOM I STEERING. The Works are having considerable trouble in producing New PhantomCodename for PHANTOM I steerings so that they are free and which will self-centre readily. Attached is a chart which we have given to the Works. We have proved that the whole trouble is in the efficiency of the nut and worm. The figures which we give on the shart are those which we have obtained on experimental steerings and which provide a satisfactory steering on the car. In order to arrive at the efficiencies given on our chart, it is necessary to have a good even bed on the nut and worm. We frequently get nuts and worms which when first made only give an efficiency of 50%, and by polishing up the worm and improving the bed, we can increase it to 80%. We have had complaints about the New PhantomCodename for PHANTOM I steering that after a long run it does not self-centre, in other words, it is stiff. We have heard from Dodd who is driving R.{Sir Henry Royce} at Le CanadelHenry Royce's French residence, that on the Phantom car that they have there, on the left-hand lock the steering will not always self-centre. We claim therefore that the Works have got to produce steerings with the nut efficiency given on our chart; the steerings when made that way will remain like it. The usual complaint with our steerings in the past was that they always became much freer with use. We should like to have your views on this matter. As a matter of interest we should like to know what advantage we gain from the larger diameter of worm. I understood at the time that there was a definite advantage in the larger diameter, irrespective of the lead. Hs.{Lord Ernest Hives - Chair} | ||