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).
Difficulties experienced with contact accelerometers for suspension systems.
| Identifier | ExFiles\Box 138\2\ scan0043 | |
| Date | 1st July 1926 | |
| 74680 X8410 X912 To OY. from Hs{Lord Ernest Hives - Chair}/Rm.{William Robotham - Chief Engineer} Hs{Lord Ernest Hives - Chair}/Rml/LG6. 7.26. SUSPENSION. As we have now had considerable experience with the contact accelerometers which we have made (similar to the sketch which you sent us), we thought it might be of some assistance to you if we enumerated some of the difficulties which we have experienced. In the first place we found that there was too much friction on the spindle carrying the inertia element. We fitted small ball races with improved results. We found that it was quite impossible to obtain any satisfactory results with the electro magnetically operated Veeder Revolution Counter because its action was too slow. The maximum number of cycles which we could make this counter register was 600 per minute (i.e. a break of one-twentyth of a second proved to be the minimum necessary for its operation). When it is a question of just reading or just not reading an acceleration, we find that one-twentyth of a second is far too slow. We have therefore been using in conjunction with the contact accelerometer our 3-pen Chronograph. This can certainly record breaks up to about one-thousandth of a second in duration. We have taken a large number of records with this Chronograph and our main difficulty has been with the contacts of the accelerometers. In spite of using squads of condensers between the points, we cannot keep them in sufficiently good condition, contd :- | ||