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Hubert Schillings also uses built-up crankshafts in many of his multi cylinder engines. See his book "Boxer-, Reihen- und V-Motoren als Modell"Schillings uses a much simpler way to couple the crankshaft pieces than the Hirth coupling. Shillings uses four round dowel pegs, in reamed holes, for alignment and power transmission.
Quote from: Vixen on January 02, 2021, 07:23:26 PMHubert Schillings also uses built-up crankshafts in many of his multi cylinder engines. See his book "Boxer-, Reihen- und V-Motoren als Modell"Schillings uses a much simpler way to couple the crankshaft pieces than the Hirth coupling. Shillings uses four round dowel pegs, in reamed holes, for alignment and power transmission. I have been searching for a copy of that book & basically given up. But thanks for that description, I understand the layout. Hmm.. interesting option, something to include in the mock-up test.
Hello PeterthaMercedes Benz finally went over to built up crankshafts with Hirth couplings in the 1950's and used them in the world beating W196 driven by Moss and Fangio.Mike
Hello PeterthaAs you well know, I have a great interest in the pre-war 'Silver Arrows' Grand Prix race cars built by Auto Union and Mercedes Benz.All the pre-war Mercedes Benz crankshafts were machine in one piece with split roller bearing for both the Main and Big End bearingsMercedes Benz finally went over to built up crankshafts with Hirth couplings in the 1950's and used them in the world beating W196 driven by Moss and Fangio.Perhaps the Auto Union/ Mahle way of finish grinding the journals would also help you and me achieve the required accuracy in our model crankshafts.Stay safeMike
Hirth made a lot of trainer aircraft engines HM 504 fourcylinder engines .Crankshaft was assembled from 36 Hirth splines without roller conrods .Ground as a single crankshaft.Dismantled again and put inside a single undivided crankcase with connecting rods.Some are still flying today untouched.Nobody dares for fear of not working againhttps://www.homebuiltairplanes.com/forums/media/wp_20190822_001-1.79558/full?d=1566463915
One side has a course pitch right hand thread while the other has a fine pitch left and thread
QuoteOne side has a course pitch thread while the other has a fine pitch threadActually, don't they need to be the same hand? The one pitch just needs to be coarser than the other so that it gains a slight amount over the trailing fine pitch. The differential being the difference in lead. I used M16x1.5 and M16x1.25 because taps were readily available for an effective lead of 0.25mm*rev. Some experimentation was required to figure out how many thread 'head start" the fine pitch was given before engaging the coarse so that when it nipped up tight the ends of the differential bolt (or stud, actually) ended up flush with the adjacent surface as desired. If the threads were opposite hands, wouldn't the pitches be additive (in the previous example, 2.75mm*rev)?-Doug
One side has a course pitch thread while the other has a fine pitch thread