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For a successful business, "time is money", however, when you are retired "time is for pleasure"
Thanks John,The final part of the Bristol Mercury jigsaw is the propellor speed reduction gearbox, which is mounted at the very front of the engine. The 2:1 reduction is achieved in a compact bevel, epicyclic gear set. The large bevel gear at the front, is rigidly bolted to the bell shaped outer cover and does not rotate. The large bevel gear at the rear is rotated by the engine's crankshaft via the splined coupling. The three smaller bevel pinions rotate the splined propeller shaft at half the speed of the crankshaft. The 2:1 speed reduction allowed a much larger diameter and therefore more efficient propeller to be used. The large diameter thrust bearing at the very front, transmits the whole of the propellers thrust into the bell shaped cover. The engines crankshaft does not see any of the propeller's thrust force.The normal cruising speed for the Mercury Mk VIII was 2400 RPM, while the maximum speed (at takeoff boost) was 2650 RPM. The actual propellor speed being half of that.For the 'exploded' display, I did not want to hide the reduction gears within the bell shaped cover, in there, it would have been completely out of sight. I decided to manufacture a completely new perspex front upright, so that the reduction gearbox could be displayed immediately below the bell shaped outer cover.This is how the front of the new display turned out. A few weeks work has completely transformed the 'exploded' display.That's my other big radial engine, the 1/3 scale Bristol Jupiter in the backgroundThere are still one or two bits to sort out, but the majority of the changes to the 'exploded' Bristol Mercury Mk VIII display have now been completed. My wife and I are about to depart for a late summer holiday to belatedly celebrate our 50th wedding anniversary. I will quickly finish the Mercury display when we return, then it's back to work on the Jupiter engine.Mike