Author Topic: Unusual Corliss  (Read 4514 times)

Offline Caber

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Re: Unusual Corliss
« Reply #30 on: June 22, 2024, 07:22:22 PM »
Well all the parts are made and engine norms disassembled for paint. I have tried posting a couple of times but the posts have vaporised. Here is assembled engine

Offline crueby

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Re: Unusual Corliss
« Reply #31 on: June 22, 2024, 07:53:01 PM »
Looking great! Really like the details on the valve pieces.  :popcorn:

Offline Caber

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Re: Unusual Corliss
« Reply #32 on: June 23, 2024, 08:02:18 AM »
Thanks!

Next question is what to use as gasket material. The stuff I have is a bit thick for this size of engine and will create some issues with the smaller parts!

Offline modelsteam

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Re: Unusual Corliss
« Reply #33 on: June 23, 2024, 08:54:45 AM »
Hi.  I use .25mm  PTFE sheet. It's easy to cut with a craft knife and punch holes in . It's works for me. Sample quantities are available on Ebay.
        Good luck with your Corliss .
                Chris

Offline Caber

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Re: Unusual Corliss
« Reply #34 on: July 16, 2024, 06:00:17 PM »
I decided to go with oiled paper gasket material that is about 2.5thou for dimensionally critical gaskets I found a small sheet among my existing gaskets.

My next problem is setting up the valve gear. The working end is straight from the MEM drawings but the operating linkage is all to my design. I have struggled a lot with trying to resolve the angular movement required to operate the valves in the cylinder block. My thinking was I needed to open and close the drillings forming the port between valve chest and cylinder but have come to realise that I need the valve to control the opening of the valve chest to the valve shaft. I presume this is a compromise for the model as efficiency wise this massively increases the volume of steam to start moving the piston. Looking at it this way with an angular offset of 15degrees for the ports, a valve chest opening of 45degrees the effective angular movement of the valve is 30 degrees less a bit to stop overrunning the cylinder ports.

When I try and work out the angular displacement at the valve from the  MEM drawings I get 60.1 degrees which seems wrong. The most uncertain measurement is the effective length of the valve lever which is not dimensioned on the drawing. I am scaling that as 0.3

I would be grateful if anyone could idiot check my thinking on the valve angles or advise how they managed with setting timing and what angular displacement they have on their engine!


 

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