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).
Observations of Packard's engine and gear production methods.
| Identifier | ExFiles\Box 127\1\ scan0168 | |
| Date | 10th February 1932 | |
| X435. R.{Sir Henry Royce} From Hs{Lord Ernest Hives - Chair}/Rn.{Mr Robinson} (In U.S.A.) c. to Sg.{Arthur F. Sidgreaves - MD} Wor.{Arthur Wormald - General Works Manager} c. to E.{Mr Elliott - Chief Engineer} Da.{Bernard Day - Chassis Design} c. to By.{R.W. Bailey - Chief Engineer} February 10th, 1932. PACKARDS. These people are very different to General Motors. However we had a look round their production line, they are doing about 100 of the new 1,800 # eights a day, and their methods were really very instructive as they make a good job. First and foremost the secret of their job is that there is no finessing. Their engine unit is erected in 7hrs. 27mins. and it is a rarity to have to do anything further to it after completion. Average road test two hours. Same with the gearbox. They have rigs running in silence chambers and when the gears are quiet on the rig they dont have to pull them out of the box. Any gears passed off that are later rejected have to be quietened in the operatives own time so that you can guess there are not very many. They test the over run as I have previously described. The whole of the rest of their practice confirms almost exactly the Cadillac mans views which I gave you in my last note. They use 45° helix, 12° pressure angle, working depths 2.5 diametral pitch, relieve as described and Incolap to get surface finish. They too are not thrilled with grinding. They get 100 sets of reasonable quiet gears off a day with 8 pitch gears. !! The works is a replica of all others, each man works just as many machines as he comfortably can, usually two probably three. The machines that tickled me most was a multiple spindle (eight) Coulters profile miller for doing combustion chambers, limit error of capacity .2 c.c. complete head 2½mins. They say this is far cheaper than holding the foundry to fine limits and is necessary for a smooth engine. This would be just the machine for aero engine rockers or the panels of connecting rods if we must machine the latter though few people do here. They also had a very simple, rigid and accurate fixture for boring crankcase main bearings to .001, the case being held vertically, total time for set 3 mins. Sft.{Mr Swift} has particulars and of many other machines. All tapping is | ||