Gordon Cheape Compound

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Martyn39
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Re: Gordon Cheape Compound

Post by Martyn39 » Mon Oct 15, 2018 5:28 pm

Thank you Dietrich that clears that point up. I will therefore not be using those fixing points.
What are the items in the third picture please?
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dampfspieler
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Re: Gordon Cheape Compound

Post by dampfspieler » Mon Oct 15, 2018 7:37 pm

Hi Martyn,
... What are the items in the third picture please?
that is am air chamber. How it works and why it should be used you can find here.

Here some pics of my solution.
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WiKe027kl.jpeg
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A very interesting book answering a lot of your questions is "The stokers manual".


Best Dietrich
Martyn39
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Re: Gordon Cheape Compound

Post by Martyn39 » Mon Oct 15, 2018 8:24 pm

Thank you for the info. To stop me asking any more dumb questions I have ordered the book from ebay.
RGSP
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Re: Gordon Cheape Compound

Post by RGSP » Tue Oct 16, 2018 7:56 am

Martyn39 wrote:
Mon Oct 15, 2018 8:24 pm
Thank you for the info. To stop me asking any more dumb questions I have ordered the book from ebay.
Questions are sensible, not dumb. It's not asking questions when you don't know things that's dumb.
Martyn39
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Re: Gordon Cheape Compound

Post by Martyn39 » Tue Oct 16, 2018 3:08 pm

A friend of mine makes injectors and wants to build a new test boiler for them rated at 200 psi and we thought it would be a good idea to make the boiler big enough to power this engine so that we don't have to just use compressed air.
Can any of you recommend a suitable design? He has the steel tube and end plates already. He is a competent welder and he has all of the hydraulic test equipment, so this is not a dangerous backyard experiment.
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Lopez Mike
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Re: Gordon Cheape Compound

Post by Lopez Mike » Tue Oct 16, 2018 7:24 pm

I STRONGLY recommend looking at existing designs. There is a good deal more to boiler construction than good welding and testing. The devil is in the details.

As an example, if you are considering a fire tube boiler, recessing the tube sheets back from the ends of the shell is important. Others will chime in here with similar design ideas. I have little familiarity with water tube boilers but I'm sure there are important things to consider.

In a fire tube vertical boiler, I recommend a water leg design. If a surface cannot 'see' the flame, it will contribute much less to steam generation.

Fuel and heating area are good places to start your thinking.
Galileo - Great mind.
Newton - Genius mind.
Einstein - Extraordinary mind
Me - Never mind.
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Re: Gordon Cheape Compound

Post by steamboatjack » Wed Oct 17, 2018 8:12 am

You need to join the steam boat association!
Martyn39
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Re: Gordon Cheape Compound

Post by Martyn39 » Wed Oct 17, 2018 4:37 pm

Now comes the difficult part. As the diagram you posted shows, the valve lap is 73 thou on the HP and 102 thou on the LP, can anyone tell me what the valve travel should be in Full Gear and in Mid Gear? The valve gear as built looks to be symmetrical so I suppose the valve travels' will be equal, but as I can't find drawings I don't know if that is correct. All of my valve gear books (6), which are for locomotives, show Joy valve gear with the usual expansion links and not the swinging links that I have. Equally none of these books show me how to lay out the gear with the design criteria needed to establish valve travel.
I am going to the Midlands Show on Friday and hope to meet some of the SBA members who are usually there. I will never have a steam boat but would like to pass this on to someone who has when I have sorted out the final details. I have come to the conclusion that the engine was built by an excellent engineer but the parts were never fitted. Having now fitted the correct shims and spacers I can fully appreciate the workmanship that went into the engine.. This work is nearly complete so I hope I don't fall at the last hurdle over the design of the valve gear.
I understand Hugh Mothersole was associated with Reeves or may have worked for them, but so far the internet has not enabled me to find him to see if he still has any drawings.
Thank you again for your patience.
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dampfspieler
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Re: Gordon Cheape Compound

Post by dampfspieler » Wed Oct 17, 2018 7:50 pm

Hi Martyn,
can anyone tell me what the valve travel should be in Full Gear and in Mid Gear?
in full gear - 2x (port width + lap)
in mid gear - should be zero
Bildschirmfoto vom 2018-10-17 21-48-40.png
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You have tryed DOCKSTADERS valve gear simulation? If not here you can find the right file - http://www.billp.org/Dockstader/ValveGear.html
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Re: Gordon Cheape Compound

Post by Martyn39 » Sat Oct 20, 2018 5:27 pm

I had a really good meeting yesterday, at the Midlands Model Engineering Exhibition, with the guys from the Steam Boat Association and met a chap who can contact Hugh Mothersol for me. Maybe there is a chance that I can get hold of the drawings after all. I also bought a book from the SBA in which was a report from a chap who had built this engine. In it he mentioned some issues that he found with the drawings as well.
Hopefully this will lead to some better information being available soon.
The engine is back together, just waiting to collect the cast iron for the piston valves next week. I now have all of the dimensions of my engine ports so should be able to machine them straight away. It looks like I need a valve travel of about .650" but I still haven't resolved the issue of the different travels of the two piston valves. Either the information re the different laps is incorrect or the design of the valve gear should be different from one cylinder to the other.
Hopefully I will try to run the engine on compressed air in a couple of weeks if I can work out how best to set the valve gear.
Martyn
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