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).
Frame construction defects, material choices, and pricing for the Wraith frame.
| Identifier | ExFiles\Box 113\5\ scan0045 | |
| Date | 29th January 1937 | |
| -4- RHO12/MJ.29.1.37. Cont'd.{John DeLooze - Company Secretary} (9) The stiffening plates at the front end of each channel are badly out of position. In each case the outer plates are low, bringing the bosses badly out of centre, while the inner plates are offset towards the rear, relative to the outer plates. It was pointed out that the fixing of the front suspension was most important and it is considered that the drilling of the stiffener plate should act as a definite location and must, therefore, be strictly accurate as regards position relative to the engine mounting. HPS.{Horace Percy Smith - Experimental Factory Mgr} was asked how this frame compared with the first one in this respect, and stated that the first frame was better owing to the thicker gauge material, which was .093 section as compared with .080 for the second, the object of the reduced section being to cut down weight, the saving being approximately 20 lbs. In view of the difficulty experienced with the second frame of thin gauge steel, which is due to spreading of the metal when spot welding, Rubery Owen have recommended that the spacing of the spot welds should be increased as much as possible. The D.O. are therefore instructing 1.5 spacing of spot welding on the straight portions and 1" spacing on bends, which will be introduced on the third frame. (10) The two front arms of the cruciform member are badly buckled and distorted, apparently due to stretching after welding. It is apparent that the front ends of the frame sprung out on removal from the welding jig, and an attempt has been made to close them by stretching. It is observed that the channels now close in .375 when the temporary cross member at the front is removed. Here again it was agreed that the light gauge material is prone to distortion and manufacture would be facilitated by the use of the heavier gauge material. (11) Both rear spring anchor brackets are .100 forward of the true position. It is considered that when the frame is built up this defect will not be apparent, but it is, nevertheless, important that the location of the spring brackets should be in accordance with specified dimensions. Mr. Buckley was asked if he could give us an approximate figure for the Wraith frame, and he has since given by telephone a price of £42. 10. 0d. each, for nine frames. For quantities of 200 Wraith frames they have quoted a price of £25 each. This should receive further investigation before acceptance. | ||