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).
Continued procedure for conducting a chassis skid pad test, covering steering ratio, theodolite setup, and sighting aids.
| Identifier | ExFiles\Box 155\4\ scan0058 | |
| Date | 30th April 1940 guessed | |
| E.R. 51. VAUXHALL MOTORS LIMITED SCHEDULE No. 216 SHEET No. 2 ENGINEERING TEST PROCEDURE CHASSIS SECTION SUBJECT SKID PAD TEST PROCEDURE (Contd). PLOTTING CURVE OF STEERING RATIO PAGE 10. The car is set up with its front wheels on turn tables and the wheels are turned from lock to lock, front wheel and steering wheel indicator readings being taken every 60º of movement of the latter. On cars with parallel steering the angles of the front wheels should be approximately equal but on opposite sides of the straight ahead zero as the steering wheel is turned from lock to lock. If this is not so it is an indication that the supporting pillars for the front wheel indicators are not parallel to the pivot pins, asd escribed under a previous heading. On new cars, of any type, it is as well to check the indicators by comparing their readings with those of a Bean wheel alignment gauge. In certain cases the indicators may have to be calibrated. SETTING UP THEODOLITE ON STAND. The stand should be set up reasonably level in the back of the car, as described previously, and the theodolite mounted upon it. Accurate levelling of the theodolite is unnecessary as angle measurements taken on the skid pad are all relative to zero and at zero speed both roll angle and attitude angle must obviously be taken as zero, so that any errors in this direction can be corrected graphically when plotting results. There is a friction effect, in roll, as noted on sheet 1 of this schedule. HEIGHT OF TAPE ON CENTRE POLE. This height is arrived at by sighting the pole through the theodolite with the car stationary on the driving circle and with the theodolite reasonably level. There is insufficient height variation between respective cars to necessitate altering the tape height once it has been fixed, for reasons stated above. SIGHTS ON THE FRONT OF THE CAR. As an aid to the car driver in keeping the car exactly on the circle "sights" of some convenient form are attached to the front of the car, the cross tube between the front wheel indicator pillars presents a convenient mount for these. Signed.................. Dated.................. Approved.................. | ||