Corliss Steam Engine (Coles Power Models)

[ZAPJACK]

This are the exhaust and intake ports. Here comes the rotatives valves
LeZap

 

[Richard Hed]

This are the exhaust and intake ports. Here comes the rotatives valves
LeZap
View attachment 122771View attachment 122772View attachment 122771View attachment 122772

After looking over your beautiful stuff, I want to re-do some of my stuff on the same Corliss. One thing I thimpfk I absolutely must re-do is the Throttle Body. This is Stainless and difficult to do. I did one but would like to redo it as I have learned a little since then and I needs two anyway.

I have a suggestion, it may be too late already as I see you have the ports milled out. Anyplace where a fluid flows, ttry to NOT have square and flat areas where 'bounce' occurs. Use ball end mills to get a curved surface where the fluid can slide instead of bounce. Thimpfk of a kidz' slide on a playground where they slide down. Instead of slide, what if the kidz simply fell off the end of the top? Rather abrupt and a bit bouncy. Bounce in steam is wher the fluid is bounced off a wall and interrupts the steam flow, if it 'slides' instead, it interrupts much less, increasing efficiency. There is an exact formula, but even a 45deg angle will help tremendously. Also, polishing or close to it, fine milling, is a goo thing to do where ever there is fluid flow as turbulence is caused by any roughness of the milling and turbulence really decreases efficiency. In ONE case, you WANT that turbulence, that is at the piston/cylinder wall to act as rings do.

 

[plipoma]

Not about ropes but about piston rings. In IC engines, because of the very high peak pressure during combustion, good sealing rings are very important to reduce the ill effects of blow-by.
My experience with small scale model steam engines that in most cases can run on 5 to 15 Lbs. of pressure and around 100 RPM, blow by can be insignificant when a smooth fit (.001" clearance) between piston and cylinder is used. The friction of most any form of contact piston rings far offsets the effects of blow by. Usually cutting a couple of small grooves around the piston (.02" wide by .02" deep) creates enough turbulence to cause an effective air seal.

 

[justintime]

Nice workshop & work.
I realy like your machines. I,m a fan of Schaublin. I used Shaublin when I worked as a toolmaker in1970.

Great work, I absolutely love seeing Schaublin equipment of any type, loved that brand from first one I saw, beautiful stuff !

 

[ZAPJACK]

And the bonnet and valve port cover
LeZap

 

[Richard Hed]

And the bonnet and valve port cover
LeZap
View attachment 122815View attachment 122816View attachment 122817View attachment 122818View attachment 122819

On my Corliss, I redesigned the parts in this last photo. For the live of me, I could not figure out why the bases of these steam/exhaust bonnets were made in two parts. The only thing that comes near to the necessity is putting part 37 in your section view into the base part. However, that fits nicely thru the side opening just fine--so why the two parts? If anyone knows, please let me know.

 

[ZAPJACK]

@Richard Hed : It's alway possible to simplify the original design, but I want to keep the spirit of early 1946. Thanks to Eloda Ray.
LZ

 

[ZAPJACK]

Pictures speak for themselves
LeZap

 

[Richard Hed]

@Richard Hed : It's alway possible to simplify the original design, but I want to keep the spirit of early 1946. Thanks to Eloda Ray.
LZ

I understand completely however, I am of a different mind. I want the same results, the same look but if two parts can be made into one and still get all the other parts into it properly, to fit correctly and to operate correctly, then I consolidate them

 

[ZAPJACK]

Can someone please explain how the exhaust valves closes?
Thanks
LeZap

 

[Pierkemo]

Nice work Zapjack!!

 

[ZAPJACK]

Now the gear and rods of the Corliss system
The third picture is the Schaublin spherical turning apparatus.
And of course, left and right tread.
LeZap
LeZap

 

[Richard Hed]

Now the gear and rods of the Corliss system
The third picture is the Schaublin spherical turning apparatus.
And of course, left and right tread.
LeZap
LeZapView attachment 123072View attachment 123073View attachment 123074View attachment 123075View attachment 123076

Beautiful L and RH threads

 

[ZAPJACK]

Can someone please explain how the exhaust valves closes?
Thanks LeZap

Nobody for the explaining?

 

[Richard Hed]

Nobody for the explaining?

It is rather straight forward how it works.; The only snag is getting the valves in the correct configuration, both L and R hand valves. the opening is a bit larger width as well as the angle compared to the steam valve. Have you got those correct? It's very tricky. the valve has to be carefully timed when you tighten the bolt into the exhaust rod. The arm that the expansion of the top of the exhaust rod "clamps" to is attached to your wonderful adjustable connecting rods which in turn go to the rocker In the center of the cylinder. I notice in your parts that your steam and exhaust rods do not yet have the bored, threaded and split ends which you need. I have put a jpeg in showing the end. I hope this helps but if not let me know

 

[ZAPJACK]

@Richard Hed, The four rods are finished, but the split have only 0,3mm (0,012") thick, so not visible but it work very well;
I understand (more of less) how the Corliss work. But to adjust all the parts together it's another song!
But I don't understand how exhaust valves closes. For the opening, it's clear.
There no fix link, only the dashpots at the end, but completely free
LeZap

 

[Richard Hed]

@Richard Hed, The four rods are finished, but the split have only 0,3mm (0,012") thick, so not visible but it work very well;
I understand (more of less) how the Corliss work. But to adjust all the parts together it's another song!
But I don't understand how exhaust valves closes. For the opening, it's clear.
There no fix link, only the dashpots at the end, but completely free
LeZap

I don't understand the problem. The exhaust eccentric operates the exhaust lever, this lever is connected to the first or right hand valve, operating it. Then this RH valve is connected to the center circle which operates the LH valve. The only thing is to make sure the correct valve is in the proper position and to make sure the valves are machined correctly.

First get the RH valve adjusted properly and working correctly, then do the LH valve.

BTW, the valve rods, I thimpfk, are incorrectly related to the valves themselves, IMNSHO. In the drawings, the valve has the raised 1/16th X 1/16th raised portion which fits into the rod head. I thimpfk this is a big mistake due to the weakness of cast iron. If the two positions are reversed, that is, the female portion is in the cast iron, it is much stronger. That is the way I am going to proceed. -- Cast iron - female; stainless rod - male.

 

[Richard Hed]

@Richard Hed, The four rods are finished, but the split have only 0,3mm (0,012") thick, so not visible but it work very well;
I understand (more of less) how the Corliss work. But to adjust all the parts together it's another song!
But I don't understand how exhaust valves closes. For the opening, it's clear.
There no fix link, only the dashpots at the end, but completely free
LeZap

Are you sure we're talking about the "exhaust"? The dashpots help operate the "steam" input not the exhaust. The exhaust is very straight forward, the steam input is more complicated.

 

[ZAPJACK]

Yes exactly. I speak about exhaust valves and only the closing. For the opening, it's clear.
It's a big mystery for me. Perhaps the dashpots help? But in that case by depression or vacuum?
LeZap

 

[kvom]

Dashpots are there to close the input valves after cutoff.