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).
The reversal tests conducted on single throw cranks.
| Identifier | ExFiles\Box 63\4\ scan0060 | |
| Date | 18th November 1924 | |
| Copy taken down to R.{Sir Henry Royce} 84499. by Rg.{Mr Rowledge} 18. 11. 24 To Rg{Mr Rowledge} from RHC.{R. H. Coverley - Production Engineer} C. Hs.{Lord Ernest Hives - Chair} O.{Mr Oldham} By.{R.W. Bailey - Chief Engineer} CRANK T NOV. 18 1924 RECEIVED We have now completed the Reversal Tests on single throw Cranks made to Drgs. DES 36 and 132. For the purpose of test Cranks were fitted with flywheel U 648 and Joggling Lever, which were bolted to flanges. Before Cranks were run we took a record of deflection and permanent set. This was done by applying a 750 lb load on ball end of Joggling Lever which gave 8.125 leverage. To enable us to take readings during deflection test we sweated pegs on to Cranks and arranged that all readings were taken at the same radii. At commencement of tests we ran at the speed of 600 r.p.m. but owing to the sudden failure of the first Cranks which only stood up to 400 Reversals it was decided to lower the speed to 300 r.p.m. It was also considered that with Joggling Lever bolted directly to Crank certain stresses were set up due to bending, so in accordance with your instructions we arranged a drive shaft which was mounted on an independent plummer block. We fixed up on test rig a chain driven rev counter to record the number of Reversals for each Crank. It will be seen by the following figures that Super Eagle is the best of the Standard Type Crank Web, and the Eccentric Disc is superior to the Concentric Disc. -Cont- | ||