Another Corliss Engine

[gbritnell]

Darn it Jerry,
I've always wanted to build a Corliss after seeing one of the Cole's versions many years ago. When I'm though with my current project (differential) I think I'll jump into the Corliss pond with the others.
Great work so far.
gbritnell

[Captain Jerry]

You won the battle of the bearing stand, Jerry. Nice curve on it, with a really graceful undercut chamfer.

Hugh.

Thanks, Hugh.  The chamfer is one of those unplanned opportunities.  After shaping the curve flanks with the boring head, I decided to reduce the thickness and clean up the faces with a fly cutter.  I had left the Y position locked so the center of rotation for the fly cutter matched the center of the curved flanks and by coincidence the radius of the flycutter was just a fraction greater than the boring set.  On the first pass with the flycutter, I noticed how nicely it matched.  I use a HSS bit shaped as described by Bogs with a radiused cutting end so after  finishing the face, I lowered the cutter and made infeeds from each side to achieve the chamfer.

I Like it Jerry!

Dave

Thanks, Dave.  I think I like it too, but the hard part is yet to come.  BIG flywheel, little bitty links.

Darn it Jerry,
I've always wanted to build a Corliss after seeing one of the Cole's versions many years ago. When I'm though with my current project (differential) I think I'll jump into the Corliss pond with the others.
Great work so far.
gbritnell

Good news, George.  Now everyone else building a Corliss will have to raise their sights just a bit.

Jerry

[vcutajar]

Nice work Jerry.

Now everyone else building a Corliss will have to raise their sights just a bit.

Oh no.  I'm done for. 

Vince

[Captain Jerry]

Here is a little more.

The open trunk guide, the main bearing stand, and the connecting girder are now joined into a single piece using screws, Locktite, and J-B Weld. I didn't get any photos.  I wasn't real sure how it was going to workout and I was experimenting.  It seems to have worked.  The parts seem stable in spite of being dropped on the floor twice during cleanup.

I also made a crank.  Shaft, web, and screw in crank pin.  Here is a photo of all of the parts that have been made so far, mostly bolted together. It is not bolted to the base because I am going to need a bigger plate for the base so no holes drilled in this one.  That is why it is sitting on my mill vise with the bar in the chuck to hold it down for pictures.  The little fly wheel in the pictures is just to hold the shaft in place.







The video shows the real reason for doing this trial assemble.  This is to test and verify the clearances at each end of the stroke and the clearance of the crosshead shoe and pin in the guide.  This is a prototype and since the plans are my own, there is plenty of reason to think there might be some error of calculation or creation that would be best found now.  As the video shows, the fits fit.

More to come.

Jerry




413

[Alan Haisley]

Another learning expreience for me 
Alan

[Jo]

  The little fly wheel in the pictures is just to hold the shaft in place.

I am pleased, that won't do anything to help the engine run. 

It is coming along nicely.

Jo

[Ramon Wilson]

Hi Jerry, This is coming along nicely and looking very good indeed.  Certainly turns oververy smoothly.

I'd like to know - how have you found the wearing qualities of cast iron to aluminium to be so far?

I did promise you some Corliss engine pics - I haven't forgotten that but have forgotten where I put them  - bear with me I'm sure they will turn up at some stage

Regards - Ramon

[NickG]

Nice 1 Jerry, looks good.

[Captain Jerry]

Hi Jerry, This is coming along nicely and looking very good indeed.  Certainly turns oververy smoothly.

I'd like to know - how have you found the wearing qualities of cast iron to aluminium to be so far?

I did promise you some Corliss engine pics - I haven't forgotten that but have forgotten where I put them  - bear with me I'm sure they will turn up at some stage

Regards - Ramon

Thanks, Ramon. I think this one is going to run well.  The long connecting rod will help along with a 7+ inch flywheel.

My experience with cast iron running in aluminum is limited.  I have built a number of engines with cast iron pistons with good result but little run time and no load.  The have all had o-rings for sealing.  I do not use the groove depth that o-ring makers recommend for a sliding seal because that creates to much friction and the pressures that I am using don't need that much sealing.  I make the grove depth the same as the o-ring thickness and rely on the o-ring itself to provide the contact with the cylinder wall, much like a CI piston ring.  Cast iron rings are running in aluminum cylinders all over the world so I think it should be fine.  On the crosshead shoe, I put a very small chamfer on the leading and trailing edges to allow the shoe to ride up on the oil film.  These are probably the most critical surfaces since they are subject to side loading from the con rod.

Speaking of that, I am going to set this engine up to run under.  My thinking is that provides the least crosshead guide wear.  If there were no con rod side load, just the weight of the piston rod and shoe bear on the bottom surface with almost none on the upper surface.  When an engine is set up to run "over", the side loading from the con rod adds to the pressure on the bottom on both outward and inward strokes.  By running under, force is directed to the upper guide surface (minus the weight of the shoe and piston rod). 

It seems that most engine run "over" and that is surely correct where the sole or primary running surface of the guide is on the bottom as it seems to be in the UK or Europe.  In the US, more engines seem to have been built with trunk type guides.  I'm not sure why but for rolling mill engines that had a high forward/reverse cyclic operating mode, the trunk guide seems to be an advantage.

Thanks for watching. There will be more.

Jerry

PS:  I brought the partially assembled engine into the house last night thinking I might get some pictures in better light.  My 3 1/2 year old great granddaughter spotted it when she came in and asked about it so I showed it to her and let her handle it.  I showed her how to turn the flywheel and she was fascinated for several minutes, giving it very close inspection.  Finally she looked up and said " when I turn the wheel, this goes back and forth".  Is this how little girl engineers get started, Jo?

[Jo]

PS:  I brought the partially assembled engine into the house last night thinking I might get some pictures in better light.  My 3 1/2 year old great granddaughter spotted it when she came in and asked about it so I showed it to her and let her handle it.  I showed her how to turn the flywheel and she was fascinated for several minutes, giving it very close inspection.  Finally she looked up and said " when I turn the wheel, this goes back and forth".  Is this how little girl engineers get started, Jo?

Yes  , and she will need to be brought appropriate toys like mechanio sets rather than sissy/boring toys like dolls  by her grandfather.

Jo

[Captain Jerry]

PS:  I brought the partially assembled engine into the house last night thinking I might get some pictures in better light.  My 3 1/2 year old great granddaughter spotted it when she came in and asked about it so I showed it to her and let her handle it.  I showed her how to turn the flywheel and she was fascinated for several minutes, giving it very close inspection.  Finally she looked up and said " when I turn the wheel, this goes back and forth".  Is this how little girl engineers get started, Jo?

Yes  , and she will need to be brought appropriate toys like mechanio sets rather than sissy/boring toys like dolls  by her grandfather.

Jo

Probably to soon for castings, huh?

[tel]

Gotta learn to make studs first!

[Captain Jerry]

Gotta learn to make studs first!

She is 3 1/2 and has shown no interest in that yet.

Jerry

[tel]

Sensible girl!

[Bearcar1]

In due time. There are always sections of thread-all to keep her entertained in the mean time.    Capt', your engine is looking terrific so far and I truly do like how you approached the trunk guide, very realistic to be sure. 


BC1
Jim