Engines > From Plans
Unusual Corliss
Caber:
I have been thinking about building the MEM Corliss for a while. The nearest real Corliss to me is at the National Museum of Scotland. This is a reasonably locally built example, middling to small size. I was rather astonished to see that rather than the usual oscillating disk operating the valve there are instead two eccentrics with shafts directly operating the inlet and exhaust valves.
Does anyone know about this type of gear and what is the collected opinion on whether this would be simpler to make for the MEM Corliss than the designed version?
Cheers😃🏴
Jo:
American Corliss engines normally have the disc whereas British engines have the two shafts. There are various flavours of mechanisms used to get the quick cut off on full sized engines but on models you need something chunky/simple like the disc or the Throp Corliss model engine it uses Musgrave trip gear.
The Douglas and Grant Engine's valve gear could be a bit tricky to scale down and have it work. Another view of the trip mechanism:
Notice that only the inlet valves "trip".
http://www.youtube.com/watch?v=4BoDp8dSFTg
Jo
Charles Lamont:
I don't know that the oscillating plate arrangement is actually 'usual' in UK practice. The Pollitt & Wigzell engines at Markham Grange & Blists Hill have disks, but the steam and exhaust are separate, with the smaller steam disc partially hidden behind the exhaust one. I have also seen running in the flesh the the corliss valved engines at The Bratch and Mill Meece pumping stations, the Ellenroad Ring Mill engine and the 'big red engine' at The Science Museum. None of these engines has a disk, and all have independent steam and exhaust gear. There is reasonable YouTube coverage of all these engines running.
Caber:
Ok I have started my Corlis build. I am not yet decided whether to use the rocking plate or the two eccentric type gear but it is going to be based on the MEM drawings. I have started with the cylinder block being carved out of a lump of Mehanite cast iron. I roughed it to size with a shell cutter and finished with a fly cutter though surface finish still not good enough. I bored the cylinder on the lathe, unfortunately gone slightly oversize as I mis allowed dimension allowing for spring in the boring bar as it is stuck out just over 2.5”
I am proposing to drill the valve ways next maybe tomorrow though I realised I don’t have a 1/4 reamer so ordering one today. Is it better doing this before the valve chests and passages?
Caber:)
crueby:
Great to see the build start, will be watching along. For me, I like the rocking plate version just since it adds an intriguing visual dance to the engine operation, great eye candy. But, as said, there are lots of variations over time and between countries.
:popcorn: :popcorn:
Navigation
[0] Message Index
[#] Next page
Go to full version