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Post by steamlaser on Dec 23, 2014 18:16:39 GMT
I have recently picked up some castings for the small Stuart triple and they came with two sheets of circa 1955 "plans".
I have been wracking my brains on how to machine the double Cast Iron eccentrics. It would appear you have to machine them as a solid pair?
I also do not understand why there are screws within the body of each eccentric.
It also looks like I will have to invest in some 7BA and 5BA taps and dies unless I can find a close equivalent.
As soon as I have finished off the sundial I am currently working on, I am going to cover up my lathe surfaces and hopefully clean up all the rough castings so I can measure and mark them out.
Any advice would be greatly appreciated!
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nonort
Part of the e-furniture
If all the worlds a Stage someone's nicked the Horses
Posts: 279 
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Post by nonort on Feb 11, 2015 8:45:05 GMT
The center or intermediate eccentric has to be split to get it on to the crankshaft. The other problem that I had was that the overall length of the twin cylinder part of the engine for want of a better description was very close to the finished size. You could use 3mm and 2.5 mm instead of 5/7BA. I used the BA sizes as I had the studs and bolts as part of my casting set. It is a very challenging engine to build. I was very disappointed with my engine when first finished and running on air. However when put onto steam all was well. steam expands through the stages air dose not causing one end of the engine to fight the other. I made my crankshaft out of a solid billet It took me three attempts but I feel it was worth the effort. Best of luck
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Post by steamlaser on Mar 9, 2015 23:07:02 GMT
The center or intermediate eccentric has to be split to get it on to the crankshaft. The other problem that I had was that the overall length of the twin cylinder part of the engine for want of a better description was very close to the finished size. You could use 3mm and 2.5 mm instead of 5/7BA. I used the BA sizes as I had the studs and bolts as part of my casting set. It is a very challenging engine to build. I was very disappointed with my engine when first finished and running on air. However when put onto steam all was well. steam expands through the stages air dose not causing one end of the engine to fight the other. I made my crankshaft out of a solid billet It took me three attempts but I feel it was worth the effort. Best of luck Many thanks for the tips! It is slow progress as the drawings are somewhat cramped up and I am having to convert everything to Metric as I go. I recently bought the kit from my club, which had been given it, some time in the past. The base and cylinder blocks had been already machined and hopefully they will be OK. I think all the important bits are there. I found a couple of the Iron castings full of blow holes, but they are just about passable enough to use. The previous builder had bought a spare crankshaft as his first one had bent whilst machining it. I think I will build one up either from solid or fabricate it from bits. |
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